infrared spectra and characteristic frequencies of inorganic ions

Infrared Spectra and Characteristic Frequencies of Inorganic Ions

Their Use in Qualitative Analysis

FOIL A. MILLER AND CHARLES H. WILKINS Department of Research in Chemical Physics, Mellon Institute, Pittsburgh 13, Pa.

Polyatomic ions exhibit characteristic infrared spectra. Although such spectra are potentially useful, there is very little reference to them in the recent literature. In particular, the literature contains no extensive collection of infrared spectra of pure inorganic salts obtained with a modern spectrometer. In order to investigate the possible utility of such data, the infrared spectra of 159 pure inorganic compounds (principally salts of polyatomic ions) have been obtained and are presented here in both graphical and tabular form. A table of characteristic frequencies for 33 polyatomic ions is given. These characteristic frequencies are shown to be useful in the qualitative analysis of inorganic unknowns. Still more fruitful is a combination of emission analysis, infrared examination, and x-ray diffraction, in that order. Several actual examples are given. It is evident that a number of problems involving inorganic salts containing polyatomic ions will benefit by infrared study. The chief limitation at present is the practical necessity of working with powders, which makes it difficult to put the spectra on a quantitative basis.

LTHOUGH there has been a vast amount of work on the A Raman spectra of inorganic salts ( 2 , 4 ) , the study of them in the infrared has been relatively neglected. Schaefer and Mat- ossi (10) have reviewed work done up to 1930, most of which deals with reflection spectra. The most extensive surveys of infrared absorption spectra have been made by Lecomte and his coiTorkers (6, 7 ) , but unfortunately many of their data are somewhat out of date and are not always presented in the most useful form. References to studies on a few ions are given in the books by Wu (12) and by Herzberg ( 3 ) . There has recently been renewed interest in the detailed study of the infrared spectra of selected salts, as exemplified by the papers of Halford (8 ) , Hornig ( I I ) , and their coworkers. The well known Colthup chart ( 1 ) contains characteristic frequencies for nitrate, sulfate, carbonate, phosphate, and ammonium ions. An excellent recent paper by Hunt, Kisherd, and Bonham ( 5 ) contains the spectra of 64 naturally occurring minerals and related inorganic compounds.

Aside from sixteen spectra in this latter paper, there is in the literature no compilation of infrared spectra of inorganic salts obtained with a modern spectrometer. I t therefore seemed worth while to make a fairly extensive survey to seek answers to the following questions: Is it generally possible to obtain good spectra? Do the ions possess frequencies which are sufficiently characteristic to be useful for analytical purposes? What is the effect on the vibrational frequencies of varying the positive ion? Is infrared spectroscopy useful in the analysis of salts?

This paper presents the spectra from 2 to 16 microns of 159 pure inorganic compounds, most of which are salts containing polyatomic ions. A chart of characteristic frequencies for 33 such ions is given. The use of these data for the qualitative analysis of inorganic mixtures is demonstrated. Finally, a number of interesting or puzzling features of the spectra are described.

A brief classification of the various types of vibrations in crystals may be appropriate. Ionic solids are considered fiist. In a crystal composed solely of monatomic ions, such as sodium chloride, potassium bromide, and calcium fluoride, the only vibrations are “lattice” vibrations, in which the individual ions undergo translatory oscillations. The resulting spectral bands are broad and are responsible for the long wave-length cutoff in transmission. In a crystal containing polyatomic ions, such as calcium carbonate or ammonium chloride, the lattice vibrations also include rotatory oscillations. Of greater interest in this case, however, is the existence of “internal” vibrations. These are essentially the distortions of molecules whose centers of mass and principal axes of rotation are a t rest. The internal vibrations are characteristic of each particular kind of ion.

In molecular solids, such as benzene, phosphorus, and ice, the units are uncharged molecules held in the lattice by weak forces of the van der Waals type, andoften also by hydrogen bonds. The same classification into internal and lattice modes can be made. A few examples of such solids are represented in this paper (boric acid, and possibly the oxides of arsenic and antimony).

Finally there are the covalent solids, such as diamond and quartz, in which the entire lattice is held together by covalent bonds. Here the distinction between lattice and internal vibrations disappears. One might a t first expect an ill-defined and featureless spectrum, but such is not the case. Actually there are bands that are very Characteristic. The situation is in some ways analogous to that in a polymer, which in spite of its size and complexity possesses a remarkably discrete spectrum. Silica gel is the only representative of this type included here.

EXPERIMENTAL

Origin and Preparation of Samples. Practically all the samples were commercial products of C.P. or analytical reagent grade. The samples were gound to a fine powder to minimize the scatter- ing of light, and were examined as Sujol mulls. When there were spectral features that were obscured by the Sujol bands, the samples were either run as a dry powder or mulled in fluorolube (a mixture of completely fluorinated hydrocarbons. Fluorolube is a product of the Hooker Electrochemical Co., perfluoro lube oil of E. I. du Pont de Semours & Co.). Some compounds, such as ferric nitrate nonahydrate (No. 49) and calcium permanganate tetrahydrate ( S o . l50), seemed to mull up in their own water of hydration. When the fine powder xas rubbed between salt plates, it acquired the appearance and feel of a typical mull, but no appreciable fogging of the salt plates resulted. For other compounds, such as potassium carbonate, breathing on the sample achieved the same result. This is not recommended, however, for it varies the water content unnecessarily, and with potassium carbonate some of the bands are shifted.

Although these techniques are satisfactory for qualitative examination, it may be of interest to list some other methods which have been mentioned in the literature for handling inorganic solids. Lecomte, who introduced most of them, has pointed out that a finely ground dry powder scatters very little radiation of wave length greater than 6 microns and consequently it may be used directly in that region (6, 7 ) . He also suggests coating

1253

1254 A N A L Y T I C A L C H E M I S T R Y

Table I. Index to Infrared Curves and Tables of Data Formula No. Type Formula No.

Boron hletaborate 1

2 3

Sulfur (Contd.) Sulfate

Tetraborate 4 5 6

Perborate

Misc.

Carbon Carbonate

7

8 9

Bisulfate

Thiosulfate L1&03 NazCOz KzCOa 3hfgCOs hlg(OH)n.3HzO CaCOa BaCOa coco3 PbCOa SHiHCOa NaHCOa KHCOa

10 11 12 13 14 15 16 17 18 19 20

Metabisulfite

Persulfate

Selenite Selenium

103 104 105 106

Bicarbonate

NazSeOa CuSeOa, 2H20

(NHhSeOi NazSeOi. lOHzO KzSeOh CuSeOl. 5HzO

NaC108

Ba(Cl0s)z. Hz0 KClOa

107 108 Cyanide

Cyanate

Thiocyanate

NaCN KCY

KOCX AgOCN

21 22

23 24

Selenate 109 110 111 112

NHISCN NaSCN KSCN Ba(SCN)z. 2Hz0 Hg(SCS)z Pb(SCN)z

Chlorate 113 114 115

Perchlorate NHiClOi SaClOa, H20 KClOa Mg(CIO*)z

116 117 118 119

Silicon Metasilicate 31

32 Bromine

Bromate Silicofluoride Silica gel

NazSiFs 33 SiOr , XHZO 34

NaBrOa KBr03 AgBrOa

120 121 122

Sitrogen Nitrite

Iodine Iodate Nah-02

KNO? AgNOz Ba(SOz!z Hz0

36 36 37 38

123 124 125

126 Periodate

Metavanadate

Chromate

Vanadium

Chromium

KIOi Nitrate 39

40 41 42 43 44 45 46 47 48 49

50

127 128

129 130 131 132 133 134 135 136

(NHl)zCrOa NazCrOi KzCrOa MgCrO4.7HzO BaCrOb ZnCrOa, 7HzO PbCrOa Alr(CrOd8 Subnitrate

Phosphate, tribasic Phosphorus

BiOSOz.Hz0

51 52 53 54 55 56 67 58 59

(NH4)zCrzOi 137 NazCrtO~. 2H20 138 KzCrrOr 139 CaCrzOl.3HzO 140 CuCrzOr ,2Hz0 141

Molybdate NazMoOi, 2HzO 142 Kd~foOi.5HnO 143

Heptamolybdate (~Hdahfo7O24.4HzO 144

Molybdenum

Dichromate

Phosphate, dibasic (NHdzHPOi 60 hazHPOi.12HzO 61 KiHPOi 62 MgHPOi. 3Hz0 63 CaHPOa. 2H20 64 BaHPOi 65

Tungsten Tungstate NanWOi.2HzO 145

KzWOI 146 CaWOi 147

Permanganate NaMn04.3HzO 148 KMnOi 149 Ca(MnOi)*.lHzO 150 B a ( M n 0 h 151

Manganese

66 67 68 69 70

Complex ions Ferrocyanide NarFe(CN)a. 10HzO 152

KdFe(CN)o. 3Hn0 153 c a ~ F e ( C N ) a . 12Hz0 154

Ferricyanide KaFe(CN)s 155 71

Orthoarsenate, tribasic Car(.4sOi)z 72 Orthoarsenate, dibasic NazHAsO4.7HzO 73

PbnHAsOi 74

Cobaltinitrite NasCo(N0r)o

Hexanitratocerate (NHdzCe(N0ah

156

157

158 159

Chlorine Chloride NHhCl

BaCln. 2Hz0

Orthoarsenate, monobasic KHz.4~04

Oxide AszO:

75

76

Mulling agents Nujol, fluorolube 160 Antimony

Sulfur

Oxide SbzOa 77 Sbzos 78

Sulfite (NHI)ZSOS HzO 79 NazSOa 80 KzSOa 2Hz0 81 CaSOa 2Hz0 82 BaSOa 83 ZnSOs 2H20 84

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1255

Table 11. Positions and Intensities of Infrared Absorption Bands v w = very weak w = weak m = medium s = strong v s = verystrong s h = shoulder b = broad vb = verybroad sp = sharp imp. = impurity * = KBr region (15-25~) eyamined

C m . - 1 Microns I Cm. -1 Microns I Cm. -1 hficrons I Cm. -1 Microns I 1. Sodium metaborate 9. Boron nitride 20. Potassium bicarbonate 31. Sodium metasilicate

NaBOz BN KHCOa NarSiOa. 5Hz0 862 11 60 w 925 10 80 vs, b

1175 8 50 ni 1310 7 64 rs 1655 6 05 m 3470 2 85 YS, vb

810 12 .35 w 1390 7 . 2 s

10. Lithium carbonate LipCOp

864 11 .58 in 1445 6.92 s 1490 6 . 7 s

11. Sodium carbonate NapCOa

700 14.3 in 705 14 .2 m 855 11 .7 v w 878 1 1 . 4 s

1440 6 . 9 5 vs 1755 5 . 7 m, sp 2500 4 . 0 m 2620 3 . 8 2 vw

-3000 - 3 . 3 m, vb

12. Potassium carbonate KzCOa

865 11.55 m 900 11 .1 vw

1450 6 . 9 vs -3220 - 3 . 1 m, vb

13. M a nesium carbonate basic 3 M g e O ~ . Mg(OH)n.3H;O

800 1 2 . 5 vw 855 11.7 v w 885 11.3 vw

1430 7 . 0 vs 1490 6 . 7 v s 3450 2 .9 111, vb

14. Calcium carbonate CaCOa

705 14.2 s 833 12 .0 s , s p 990 1 0 . 1 s

1010 9 . 9 9 1370 7 . 3 m, sh 1410 7 . 1 vs 1630 6 . 1 5 vs 2380 4 . 2 w 2600 3 . 8 5 s , vb 2950 3 . 3 7 m

715 1 4 . 0 s 775 12.9 s 832 12.03 s 980 10.2 YS

1125 8 . 9 m 1165 8.58 m 1695 5 . 9 m 2330 4 . 3 m 3280 3 .05 vs, vb

2. M a nesium metaborate M % B o ~ ) ~ . ~ H ~ o

808 12.4 s 838 11 .95 m 892 11.2 vw 952 1 0 . 5 w

1005 9 . 9 5 m 1085 9 . 2 s 1130 8 .8 s 1220 8 . 2 w

32. Potassium metasilicate KtSiOa

770 13.0 vw 990 1 0 . 1 vs, vb

1625 6.15 vw 3330 3 . 0 m

21. Sodium cyanide NaCN (NasCOa impurity)

865 11.55 m , imp. 1310 7 .65 vw 1460 6 .85 vs,imp. 1640 6 . 1 m 2080 4 . 8 s 2220 4 . 5 w, vb 3330 3 . 0 m , vb

1370 7 3 s 1420 7 05 s 1640 6 1 w 3360 2 98 s 3500 2 86 s

33. Sodium silicofluoride Na2SiFa

728 13.73 v s 790 12.7 m , s h

1105 9 .05 v w 22. Potassium cyanide KCN (KHCOa, K ~ C O S impurities)

833 12 .0 m , imp. 882 11.35 vw, imp.

1440 6 .95 s , imp. 1635 6 .12 8 2070 4 .83 s

23. Potassium cyanate KOCN (KHCOa impurity)

3. Lead metaborate Pb(B0z)n. HzO 34. Silica gel

SiOz. xHzO 800 1 2 . 5 w 948 10.55 w

1090 9 , l 5 vs 1190 8 . 4 s , s h 1640 6 . 1 vw 3330 3 . 0 m

35. Sodium nitrite NaNOz

960 10 .3 s, vb 1340 7 . 4 5 m 1380 7 .2 Nujol? 3280 3 .05 m

4. Sodium tetraborate NazBiOi. lOHzO

706 14.17 s. imp. 833 12 .0 s , rmp. 980 10 .2 m, !mp.

1010 9 . 9 m , imp. 1210 8 25 m , sp. 1310 7 . 6 5 n', s,p. 1410 7 . 1 v s , !mp. 1640 6 . 1 vs, imp. 2130 4 . 7 s , yb 2630 3 . 8 s , imp.

712 14.05 w 775 12 .9 w 828 12 .1 s 843 10 .6 s 831 12.03 m, sp

1250 8 . 0 v s 1335 7 . 5 m , s h

. ~~

1000 10 .0 s 1075 9 . 3 w 1130 8.85 m 1260 7 .95 m 1275 7 .85 m 1360 7.35 vs 1420 7.05 vs 1460 6.85 Nujol? 1650 6 .05 m

715 14 .0 w 877 11.4 s , s p

1430 7 . 0 vs 1785 5 . 6 vw 2530 3 .95 v w

36. Potassium nitrite KNOz

830 12.05 s , s p 1235 8 . 1 vs 1335 7 . 5 m, sp 1380 7.25 m

24. Silver cyanate AgOCN

3330 3 . 0 vs 15. Barium carbonate BaCOa

1210 8 .25 vw 1310 7 . 6 5 w 1345 7 . 4 3 vw 2170 4 . 6 vs 3450 2 . 9 v w

2560 3 . 9 vw 3450 2 . 9 vw

37. Silver nitrite AgNOz

5. Potassium tetraborate K2BiOi. 5Hn0 697 14 .35 vi

858 11 .65 s , s p 1440 6 . 9 5 vs 705 14 .2 vw

782 1 2 . 8 vw 833 12 .0 s 918 1 0 . 9 s

1000 1 0 . 0 s 1060 9 .45 v w 1085 9 . 2 s 1130 8.85 v w 1155 8 .65 w 1240 8 .05 m 1315 7 . 6 2 sh 1340 7 . 4 5 s 1440 6 . 9 5 s 1655 6 .05 w 2480 4 03 vw 3330 3 .03 s 3390 2.95 s 3560 2 . 8 1 s

16. Cobaltous carbonate COCOS

747 1 3 . 4 vw 865 11 .55 m

1450 6 . 9 vs -3330 - 3 . 0 w, vb

17. Lead carbonate PbCOa

685 1 4 . 6 w 840 1 1 . 9 vw

1410 7 . 1 YS

25. Ammonium thiocyanate NHiSCN

1420 7 .05 s 1650 6 05 m 2050 4 88 s 2860 3 . 5 m 3060 3 .27 s 3149 3 .18 s

26. Sodium thiocyanate NaSCN

833 12 .0 w 848 11 .8 v w

1250 8 . 0 vs 1380 7.25 vs

38. Barium nitrite Ba(N0n)z. H20

820 12.2 w 1235 8 . 1 vs 1330 7.53 m 1640 6 . 1 m 3360 2 . 9 8 m, sp 3510 2 .85 m , SP

758 13 2 w 950 10 5 v w , b

1620 6 18 m 2020 4 9 8 3330 3 0 ni

18. Ammonium bicarbonate NHiHCOi 39. Ammonium nitrate

NHiNOa 6. Manganese tetraborate MnBiOi.8HzO

703 14 .25 s 832 12.02 s , sp 993 10 .08 s

1030 9 . 7 w, SP 1045 9 . 5 8 w, SP 1325 7 .55 vs, b 1400 7 . 1 5 vs, sp 1620 6 .17 s 1655 6 .05 s 1890 5 . 3 w 2550 3.92 m 3060 3 .27 V S , S P 3160 3.17 vs, sp

830 12.05 w 1340 1390 ;:i5} 1630 6 . 1 3 w 1740 5 . 7 5 w

w

3410 2.93

27. Potassium thiocyanate KSCN

746 13.4 m 945 10.6 vw, vb

1630 6.13 m 2020 4 . 9 s 3400 2.95 m

990 10 .1 1065 9 .41 s , vb 1150 8 . 7 1370 7 . 3 s 1450 6 . 9 m 1640 6 . 1 w 3390 2 . 9 5 8

7. Sodium perborate NaBOs.4HzO

28. Barium thiocyanate Ba(SCN)z. 2HzO 40. Sodium nitrate*

NaNOa 770 13 0 vw 833 12 0 w 852 11 75 w 877 11 4 vw 934 10 7 T S

1020 9 8 8 1075 9 3 m

1630 6 . 1 5 m 2060 4 .85 vs, sp 3500 2 . 8 5 vs

19. Sodium bicarbonate NaHCOs

836 11.96 m , s p 1358 7.36 vs 1790 5.59 vw 2428 4.12 vw 662

698 838

1000 1035 1050 1295 1410 1460 1630 1660 1900 2040 2320 2500 2940

15 .15 14.35 11.95 10 .0 9 . 6 5 9 . 5 5 7 .73 7 . 1 6 .85

E} 5.27 4 . 9 4 . 3 4 . 0 3 . 4

w (COZ?) R 29. Mercuric thiocyanate

Hg(SCN)z 41. Potassium nitrate KNOI 835 12 .0 vw

1105 9 . 0 5 vw 1150 8 .7 vw 1370 7 . 3 s 1615 6 . 2 w 2090 4 . 7 8 8 3450 2 . 9 w

1175 8 5 s 1240 8 05 s 1655 6 05 w 3330 3 0 vs

824 12.14 m, sp 1380 7 .25 vs 1767 5 .66 vw

8. Boric acid &BO3

807 12.4 m 885 11 3 vw

1195 8 . 3 7 s , s p 1450 6 . 9 vs 3270 3 .15 s

5

m 42. Silver nitrate

AgNOa 733 13.64 vw

803 835 12.45 11.98 w vw 1348 7.42 YB

30. Lead thiocyanate Pb(SCN)E

2030 4 .93 8 . sp 2080 4 . 8 w

v w w (COZ?) s. b


Table 11. Positions and Intensities of Infrared Absorption Bands (Continued) vw = very weak w = weak m = medium s = strong vs = very strong ah = shoulder b = broad vb = very broad sp = sharp imp. = impurity * = I<Br region (15-25p) examined

Cm. -1 RZicrons I Cm. -1 Microns I Cm. -1 Microns I Cm.-' hlirrons I 43. Calcium nitrate 54. Calcium phosphate, tribasic 63. Magnesium phosphate, dibasic 70. Calcium phosphate monobasic,

Ca(N0a)z Caa(P0a)z MgHP04.3H20 Ca(H2POa)z. ~ 2 0

820 12.20 w 1044 9.58 vw 1350 7 4 s 1430 7 . 0 s 1640 6 . 1 m 3450 2 .9 s

44. Strontium nitrate Sr(NOdz

962 10.4 v w 1030 9 . 7 ' YS, vb 1085 9 . 2 1 3230 3 . 1 m, b

882 11.35 m 1020 9 . 8 s 1055 9 . 5 s

670 855 885 915

14.9 m, vh :::: } w, r b 1160 8 6 8 10 9 ' vw, sh

10 5 s. h 9 2 s , b 8 6 w 8 1 s , b

950 1085 1160 1235 1640 2320

-2980

55. Manganese phosphate, tribasic Mns(P0a)z. 7Hz0

935 1 0 . 7 vw, sh 980 10.2 w

1020 9 . 8 s 1040 9 . 6 ? s h 1070 9 . 3 5 s 1145 8 . 7 5 w 1250 8 .00 w 1300 7 .7 w 2470 4 .05 vw 3170 3 , l5 ' ! 3330 3450 i:: I

6 . 1 m 4 . 3 m, vb - 3.35 s , v b 35 m

71. Sodium metaarsenite NaAsO,

64. Calcium phosphate, dibasic CaHPOa. 2H20 697 14.36 vs, b

748 13.35 m 775 12.9 w , a h 833 12.0 s , sp 848 11.8 s , s p

1420 7.06 v w 1460 6.85 m, sp 3450 2.90 w, b

880 11.35, m 990 1 0 . 1

1050 9 . 5 1 s , r b 1125 8 . 9 J 1350 7 .4 ? 1650 6.07 m

-2270 - 4 .4 m, vb -3000 - 3 . 3 m

3610 2.85 vw, sh

45. Barium nitrate Ba(N0s)t

729 13.72 6 , SP 817 12.24 S , S P

1352 7 .40 vs 1418 7 . 0 5 m , s p 1774 5 64 w, SP 2410 4.15 UT, b

46. Cupric nitrate Cu(N0a)z. 3Hz0

56. Nickel(ous) phosphate, tribasic Nia(P0a)~. 7Hz0

735 877 943

100.5 1060

-1440 1595

-3030 3450

13.6 w. vb 11 .4 w

6 w. Rh 72. Calcium orthoarsenate, tribasic

Ca,(AsO4)2 io . , .~. 9.95 s 9 . 4 5 w, sh

6 .27 w - 6 . 9 5 w (Sujol + ?)

65. Barium phosphate, dibasic BaHPOa 836 11.96 w

1587 6.30 6, SP 1790 5 58 vw

3360 2.98 s, b

1378 7.26 vs

2431 4.11 vw 3170 3 15 w

N 3 . 3 s 2 . 9 m , s p

57. Copper(icj phosphate, tribasic C~a(POa)2.3Hz0

645 15.5 m 855 11.7 m 925 10.8 s

73. Sodium orthoarsenate, dibasic NazHAsOa.7HzO 47. Cobaltous nitrate

Co(NOa)2.6HzO 960 10.4 s 1010 9 .9 s 1070 9 .35 s 1100 9 . 1 m , sh 1140 8.75 m 1290 7 .75 m 3390 2.95 m

2440 4 . 1 w 2700 3 . 7 w 712

836 1175 1280 1640 2175 2380

-3130 -

807 12 4 vw, r b 836 11 96 w, 6p

1372 7 29 vs 1640 6 1 m 3230 3 1 m , sh 3410 2.93 s

66. Ammonium phosphate monobasic NHaHzPOa

900 11.1 w, vb 1080 9.25 m , b 1275 7.85 m 1420 7.05 w, sh 1440 6.95 rn

-1610 - 6 . 2 w, vb -2270 - 4.4 w, vb

2900 3.45 w, sh 3050 3.28 m

58. Lead phosphate, tribasic Pbs(P0a)z 48. Lead nitrate

Pb(N0a)z 74. Lead orthoarsenate, dibasic PbzHAsOc 726 13.77 u'

807 12.39 v w 836 11.96 w, sp

1373 7.28 w 743 13.45 m , b 800 12.5 vs

59. Chromic phosphate, tribasic CrPOa. H?O

1030 9 . 7 vs, vb 1625 6.15 w 3230 3 . 1 E , b

49. Ferric nitrate Fe(NOa)a,9HzO

75. Potassium orthoarsenate, monobasic KHzAsOa

835 11.98 w 1361 7 .36 vs 1613 6.19 m 1785 5 . 6 v w 2440 4 . 1 vu. 3230 3 . 1 s , vb

750 13.3 m , b 850 11.75 m, b

1020 9 8 v w , b 1266 7 .9 m, vb 1585 6 . 3 m, vb

-2275 - 4 . 4 m. vb -2740 - 3.85 m

67. Sodium phosphate, monobasic NaH2POa. HzO 60. Ammonium phosphate, dibasic

(NHa)zHPOc

50. Bismuth subnitrate BiONOa. H20

76. Arsenic trioxide AS?Oa

803 12.45 vs 840 11.9 w, sh

1040 9 6 vw, b

816 12 27 vw 1325 7.55 s

1640 6 . 1 v w 1380 7.25 vs

3390 2.95 m, b 1640 6 . 1 m , vb 2850 4.25 s, b 2820 3.55 s , b 51. Sodium phosphate, tribasic

NaaPOa. 12H20 77. Antimony trioxide Sb2Oa 694 14 .4 real?

1000 10 .0 vs 1450 6 .9 vw 1660 6.03 m 3200 3.13 vs, b

61. Sodium phosphate, dibasic NanHPOa. 12HzO 690 1 4 . 5 w

740 18 .5 vs 950 10 .5 vw, b

68. Potassium phosphate monobasic*

KHzPOc 865 958 985

1070 1125 1145 1185 126.5 1630

-2220 3280

11 ,55 10.45 10.15 9 . 3 5 8 . 9 8 .75 8 45 7 . 9 6.13 - 4 . 5 3.05

9

S 17s

w, sh

u-, sh vw, sh w W m w, vb vs, vb

538 18 59 m 900 11.1 m, vb

1090 9.15 m , b 1300 7 . 7 m 1640 6 1 m , b 2320 4 . 3 m , b

52. Potassium phosphate, tribasic KaPOi

1000 10.0 vs, vh 1590 6 . 3 w, vb 3180 3.15 v s , b

53. Magnesium phosphate, tribasic Mga(POajz.4HzO

78. Antimon pentoxide Sbr8r

685 14.6 v w , real? 740 13.5 s , v b

3225 3 . 1 w, b

79. Ammonium sulfite (NHa)zSOa. H20 69. Magnesium phosphate,

monobasic Mg(H2POa)z

768 13.05 w, b 887 11.3 vw, b

1% %E5] ," 1040 1135 8.83 m 1155 8 . 6 5 w , s h 1230 8.13 w 1640 6 . 1 m 3260 3 .07 s 3460 2 . 9 m, sh

62. Potassium phosphate, dibasic KzHPOc 1105 9 .05 vs, b

1410 7.08 v s , sp 3075 3 . 2 5 s 837 11.95 s

934 10 .7 s 990 10.1 vs, vb

1110 9 . 0 w , s h 1350 7 .4 m, sp 1835 5.45 m 2380 4 . 2 m 2860 3 . 5 m

755 13.2 w. vb 943 10 .6

1040 9 .6 1 m , v b 1150 8 . 7 J 1235 8 . 1 w, sh 1640 6 . 1 m iii: s . b

80. Sodium sulfite Na2S03

1135 11.35 w 1215 8 2 vw

960 10.4 r s , b

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1257

Table 11. Positions and Intensities of Infrared Absorption Bands (Continued) v w = very xeak xv = weak m = medium s = strong YS = very strong sh = shoulder b = broad vb = very broad sp = sharp imp. = impurity * = KBr region (15-25p) examined

Cni.- ' Nicrons I Cm. -1 Microns I Cm. -1 Rlicrons I Cm. -1 Microns I

81. Potassium sulfite 92. Copper sulfate 101. Magnesium thiosulfate 110. Sodium selenate K?SOS. 2H20 c u s o a MgSzOr .6Hz0 Na~Se04.10H~O

913 10.6 vs, vb 1100 9.1 vs, b 1175 8.5 s 1645 6.07 v w 1885 5.3 vw. 3390 2.95 m

680 14.7 m 805 12.45 m 860 11.6 m 1020 9.8 w, sp 1090 9.2 vs, vb 1200 8.35 s 1600 6.25 w, sh

-3300 - 3.15 s , b

735 13.6 vw, sh 793 12.6 vs 838 11.95 vs 573 11.45 vs I105 9 05 m 1125 8.9 m, sp 1165 8.6 w 1240 8.07 m 1390 7.2 s 1640 6 . 1 m 2350 4.25 s 3220 3.1 m 3500 2.85 s , sp

- 665 -1n .O s 1000 10.0 s 1115 8.95 vs 1645 6.08 m 2250 4 . 4 5 > v. vb

3360 2.981 s 3450 2.9 )

3200 3.13

102. Barium thiosulfate BaSzOs.U2O

82. Calcium sulfite CaSOs. 2HzO

653 15.3 m, b :$; i::: } ~ s , h 1100 9.1 v w , v b 1210 8.3 vw 1625 6.15 m, sp 3400 2.94 s , s p

83. Barium sul5te BaSOa

93. Zirconium sulfate* ZrSOa. 4Hz0

627 15 95 w 650 15.4 w 720 13.8 w 770 13 0 vw, sh 920 10 9 vn, sh 1030 9 7 w, sp 1080 9.25 vs, vb 1630 6.12 m 1650 6.05 m 3195 3.13 s

94. Chromium potassium sulfate Crz(SO4) d . KzSOa. 24Hz0

11 1. Potassium selenate KsSeOa

810 12.35 vw.sh 824 12.13 s , sp

857 875 11.67 11.42 vw vw 89? 11.15 m 1080 9.22 vw 1110 9.0 v w 1140 8.75 v w 1375 7.28 vs 1745 5.73 w, sp 2390 4.18 w , 8 p

638 15.7 m 917 10.9 vs. b 990 10.1 w 1070 9.35 m, vb 1200 8.35 m

103.

4.56

a31 660 fifi7 973

.: I 2

lofin 11x0 1265

Sodium metabisulfite* Na&Os

2 1 . 9 1 m 14..58 m 18.81 m 1.5. 171 1,j.n / in.25 vs 0.4.5 1's 8. .5 v s 7.9 v w , sh

1090 9.2 vs 1660 6.05 w, b 3370 2.97 m

1410 7.1 vw

84. Zinc sulfite ZnSOs.2HzO

855 945 1020 1100 1160 1630 3170 3390

85.

645 1105 1410 1740 3032 3165

95. Ammonium bisulfate NHaHSOa

112. Copper selenate CuSeOa. 5Hz0 11.7 s , vb

10.57 w 9.8 s 9.1 m 8.6 m 6.13 m 3.15 2.951

855 11.7 m. b 1035 9.65 m, b 1180 8.5 m, b 1410 7 . 1 v w 3180 3.15 m

770 13.0 m, b 858 11.65 s 922 10.85 m 1600 6.25 m, sp 3220 3.1 \ 3390 2.951

104. Potassium metabisulfite KZSZO5

R R 2 1 , 5 . l rn 475 1 0 . 2 5 cs

10x0 9 . 2 i ni 1105 9 0.5 ni 117.5 R . i 7's 1250 8.0 r w , ~ h

iofin 4.ii

Sodium bisulfate NaHSOh

215.3 ni 12.95 vw

8 . 0 m 8.1 s 6.02 m 3.85 v w 2.88 m

96.

- 655 - 773

, Ammonium sulfate (NHa)zSOa 15.5 w 9.05 vs. b

113. Sodium chlorate NaClOa

935 10.7 s , s p 965 10.35: 990 10.1 ( vs 7.1 vs, sp

5 , 7 5 v w 3.25\ 3.161 s * s p

105. Ammonium persulfate (NHi)zSzOq 114. Potassium chlorate

KClOa 938 10.65 w 962 10.4 YS

fi?7 15 .7 vw 702 14.23 s

865 11 ..?.a 7-w lOR0 4 . 4 5 s , s p 1085 4 . 2 3 m, SD

-1190 - 8 . 4 w, sh 1280 7 . 8 v'

3260 3.07 E

793 12.5- w

14211 7.0.5

86. Lithium sulfate* LizSOa. Hz0

97. Potassium bisulfate KHSOa

634 15.77 m 815 12.25 vw, real? 1020 9.8 v w 1110 9.0 T S 1170 8.55 m, sh 1380 7.25 Nujol + 1 1625 6.15 m, sp 3470 2.88 m

115. Barium chlorate Ba(ClOa)n. HzO 820 12.2 w , s h

848 11 8 s 877 11.4 s 1005 9.95 5

1160 8.6 v s , b 1280 7.78 s

1065 9.37 S , SP t:;:5] vs. vb

1610 6.2 m, s p 3S40 2.83 s , s p 3570 2.80 s , sp

106. Potassium persulfate KzS201 87. Sodium sulfate

NazSOa 645 15 5 w 1110 9.0 vs

88. Potassium sulfate* KzSOa

1110 9 0 vs

710 1 4 . 1 I060 9 1? s , 3p 1270 7 88 1100 7 7 r vs 3300 3 02 w

1325 7.55 w, sh 1640 6.1 w 2:: j> m. vb 2600 3.85 v w 2900 3.45 s , vb

116. Ammonium perchlorate

1060 9.45 v s 1136 8.8 s , s h 1420 7.05 s 3330 3.0 s, sp

NHaClOa

107. Sodium selenite NazSeOa 98. Ammonium thiosulfate

(NHdzSzOa 720 18.7 vs 788 12.7 s 112.5 8.4 w , h 1450 6.9 Nuiol + ? 3330 3.0 w, b

117. Sodium perchlorate NaCIOI. HzO 89. Calcium sulfate

CaSOa. 2Hz0 667 14.95 s 1010 9.9 w, sh 1130 8 . 8 5 vs, vb 1630 6.13 s. sp 1670 5,95 w 2200 4.55 m. b 3410 2.93 s , b

953 10.5 s 1065 8 . 4 s 1390 t.18 s 1650 6.05 w

1100 0.1 vs, b 1630 6.14 s , sp 2030 4.93 vw 3570 2.80 s , sp

2960 3.4 s , vb

99. Sodium thiosulfate Na&03.5H20

108. Copper selenite CuSe08.2Hz0

714 14.0 v s 768 17.0 m . s h 807 12.4 r w , s h 918 10.9 m 1570 6.35 m

2270 4.4 vw, vb -3120 - 3.2 1 3450 2.9 1

1650 6 . 0 5 w

118. Potassium perchlorate KClOc 677 14.8 s

757 13.2 vw, sh 1000 10.0 vs 1125 8.9 1165 8.6 ) '" 1630 G,l5 w 1660 6.03 m

2080 3390 2.95 vs

90, Manganese sulfate MnSOd.2HpO

637 1 5 . 7 w 940 10.65 vw 1075 9 3 s 1140 8 . 7 5 s . SI1 1990 5 ,02 cw

660 15.15 m 825 12.1 s

1025 9.78 nr 1135 8 . 8 vs, vb 3225 3.1 s , b 109. Ammonium selenate

(NH4)zSeOa 119.

652 943 962 1060 1130 1625 2100 3540

Magnesium perchlorate MgClOi

15.35 rn 10.58 w 10.4 w 9.45 vs 8 . 85 \I

6.13 s , sp 4 . 8 P, vb 2.83 s

770 13.0 \ @ i:;i31 vs,vb 860 11.63,' 1235 8.1 w 1420 7.03 s 1640 6.1 m 2320 1.3 ni

-3140 - 3.18 v s

91. Ferrous sulfate* FeSOh. 7Hz0

611 16.37 s , v b 990 10.1 vw 1090 9.2 vs, vb 1150 8 . 7 m , s h 1625 6.15 m 3330 3.0 s , b

100. Potassium thiosulfate KzSzOs. H20

658 15.2 676 14.8 995 10 03 s 1120 8 95 v s 1625 6 15 v w 3300 3 03 w


Table 11. Positions and Intensities of Infrared Absorption Bands (ConcEuded) vw = very weak K = weak m = medium s = strong vs = very strong s h = shoulder b = broad vb = very broad sp = sharp imp. = impurity * = KBr region (15-25p) examined

C m - 1 Microns I 120. Sodium bromate

NaBrOz 807 12 .4 vs

Cm.-1 Microns Z 132. Ma nesium chromate

MgErO4.7HzO

Cm.-1 Microns I 140. Calcium dichromate

CaCrzO7.3HzO 725 1 3 . 8 vu. 830 12.05 m 900 11 .1 m 940 10.65 s

1625 6 .15 m 3450 2 . 9 s

Cm.-1 Microns I 151. Barium permanganate

Ba(Mn0a)t 695 14.4 w, vb 765 13 .1 w, b 855 11 .7 m , s h 877 11 .4 vs

1620 1650 ::I%} 2270 4 . 4 m, b 3260 3 .07 vs, b

840 11.9 m , s p 877 11.4 s 913 10.95 s 935 10.7 m 121. Potassium bromate

KBrOa 790 12.65 vs

152. Sodium ferroc anide NaaFe(CN)s. lOd0 141. Copper dichromate

CuCrz01.2HzO 122. Silver bromate

AgBrOs 1625 6.15 s , sp 2000 5 . 0 vs 2020 4.95 m, sh 750 1 3 . 3 s , vb

940 10.65 s 1625 6.15 m 3450 2 . 9 s

765 13 .08 s 797 12.55 vs

1280 7 .25 Nujol + ?

133. Barium chromate BaCrOa

i i g i i :z5} vs b 930 10.75 s , s h

3450 2 . 9 w 123. Sodium iodate

NaIOs

;;; i;:?} vs 800 1 2 . 5 m

124. Potassium iodate KIO?

142. Sodium molybdate NazMoO,. 2 H ~ 0

153. Potassium ferrocyanide &Fe (CN) 8.3H20

820 12.2 vs 855 11 .7 m 900 1 1 . 1 m , s p

1680 5 . 9 5 w 3280 3 . 0 5 s

930 10.75 vw 995 10.05 vw

1630 6.13 8 , sp 1650 6 .07 m 2015 4 .96 vs 3410 3510 ;:%}

134. Zinc chromate ZnCr04.7HzO

720 13 .9 m 795 12 .55 s 875 11 .4 940 10 .65

1050 9 . 5 1 1183 8 . 4 5 m 1620 6 .15 vw 1820 5 . 5 vw, b 2700 3 . 7 w, b 3450 2 . 9 s , b

1090 9 , l 5 s , b

738 13.55 vs 755 13.25 s 800 1 2 . 5 w

143. Potassium molybdate KzMoOa.5HzO

825 12 .1 va 900 11 .1 m

3310 3.02 m

154. Calcium ferrocyanide CazFe(CN)n. 12Hz0 125. Calcium iodate

Ca(I0s)z. 6HzO 1615 6 18 m 2015 4 . 9 6 vs, sp 3390 2 . 9 5 vs, b 748 13.35 m

760 13.15 m 775 1 2 . 9 s 817 12.25 8 827 12 .1 vw, sh 838 11.93 v w , s h

1610 6.20 w , s p 3350 3450 i::8}

144. Ammonium heptamolybdate (NHa)nMoiOzi. 4HzO

663 15 .1 vs 836 11.95 m 877 11.4 vs 913 10.95 w , s h

1420 7.05 s 1640 6 . 1 w 3080 3 .25 s , b

155. Potassium ferricyanide KsFe(CN)e

2100 4.77 s

135. Lead chromate PbCrO4

82 5 855 :::: 1 vw. vb 885 11 .3

126. Potassium periodate KIOa

848 1 1 . 8 vs

127. Ammonium metavanadate NHdVOa

156. Sodium cobaltinitrite NaaCo(N0l)s

145. Sodium tungstate NazW04. 2 H z 0 847 11 .8 s , s p

1333 7 . 5 vs 1430 7 . 0 vs 1575 6 . 3 5 m 1645 6 . 0 7 w 2665 3 .75 vw, sp 2780 3 . 6 vw, sp 3450 2 .9 m

136. Aluminum chromate Alr(CrO4)s 810 12.35 w , s h

822 12.15) 8.50 11,751 vss 925 10 .8 w

1670 6 . 0 w 3310 3.02 s

745 13.4 s , v b 950 10.5 s , b

1010 9 . 9 s 1300 7 . 7 vw 1625 6 . 1 5 m 3460 3520 ;:ii}

690 14.5 s, vb 843 11.85 s 888 11.25 s 935 10.7 s

1415 7.08 s , sp 3200 3.12 8 , sp 146. Potassium tungstate

KsWOc 157. Ammonium hexanitratocerate (NHdzCe(N0dn

128. Sodium metavanadate NaVOa .4&0

750 13.3 vw 823 12 .15 vs, b 925 1 0 . 8 w

1680 5 . 9 5 w 3170 3.15 m 3320 3 .01 w,sh

137. Ammonium dichromate

730 13 .7 vs 877 11 .4 m 900 11 .1 m 925 10 .8 s , s h 950 10.55 s

1410 7 . 1 s , s p 2850 3 . 5 m, sh 3060 3170 ::%}

(NH4zCrzOi 745 13 42 8 , sp 803 12 45 m, sh 807 12.4 8 , sp 815 12 25 vw

1030 9 7 s, sp 1050 9 5 vw 1260 7 95 vs 1325 7 55 w 1420 7 05 s 1530 6 6 vs, b 3210 3 11 s, b

693 14 .4 s, b 828 12.08 s 910 1 1 . 0 vw 935 10 .7 957 10.45}

3450 2.9 w, b 147. Calcium tungstate

Caw04 129. Ammonium chromate

(NHd)zCrO4 794 12 .6 vs, vh 1640 6 . 1 w 3390 2 .95 m 74 5

843 865 935

1410 1650 2860 2990 3120

13 .4 m 11.85 m, ah 11.55 vs, b 10 .7 m. sh 7 . 1 8 6.05 m 3 . 5 m . s h 3 . 3 5 s 3 . 2 m , s h

158. Ammonium chloride* NHiCl 138. Sodium dichromate

NalCrzOr .2Hz0 148. Sodium permanganate NaMn04.3Hz0 1410 7 . 1 8 , sp

1780 5.75 w, b 2000 5 . 0 vw 2860 3 . 5 m 3070 3150 ::?!}

13.55 vs 1 2 . 8 m 11 .25 8 . sp 11.0 m , s p 9 .07 vs 7.2 Nujol + 1

2.85 8

;:A;} 8 , SP

840 1 1 . 9 vw, sh 896 11.15 vs

1625 6 . 1 5 s , s p

3510 2 .85 s $::: ::e} w , b

130. Sodium chromate NaKrOd

159. Barium chloride BaClz.2HzO 680

820 855 890 915

1665 2125 3170

14 .7 m

i?:: 1 vs, b 11.2 10 .90 m , s h 6 .0 s , s p 4 . 7 m, b 3.15 vs .b

149. Potassium permanganate KMnOd 700 1 4 . 3 vs, vb

1615 6 . 1 8 8 , sp 1645 6 . 0 7 8 , s p 3370 2 . 9 7 vs

845 11.85 w 900 11.1 vs

1725 5 . 8 w 139. Potassium dichromate* KnCrzOi

568 17 .61 w 760 13.15 vs 795 12.55 m 885 11 .3 m, SP 905 11.05 m , s p 920 10.85 w , ~ h 940 10.65 vs, b

1305 7 . 6 5 vw

160. Nujol 2918 3.427 s 2861 3.495 a 1458 6.859 m 1378 7.257 m 720 13.89 w

150. Calcium permanganate Ca(Mn03z.4HzO 131. Potassium chromate

KzCrOh 840 11.9 m 905 11.05 vs, b

1625 6.15 8 , s p 3470 2 .88 vs

858 11.65 w, sh

935 1 0 . 7 s 11.45 vs

V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2 1259

one of the salt plates with a very thin layer of solid paraffin to hold the particles in place (6, 7 ) . The fine powder may be prepared by grinding, by evaporation of a suitable solvent (6, 7 ) , or by sedimentation ( 5 ) . Vacuum evaporation which has been used for preparing films of ammonium halides ( I I ) , may be useful for other relatively volatile inorganic materials.

8 1 1 samples were examined from 2 to 16 microns with a Baird XIodel A infrared spectrophotometer. Wave lengths are accurate to about zt0.03 micron, although for broad bands the error of judging the center may exceed this. It was sometimes found that duplicate spectra for the same compound differed by more than this amount. Some oossible reasons

Spectroscopic Procedures.

are mentioned below. Representative ex amp1 es of

several ions were examined in the potassium bromide region with a Perkin-Elmer 12B spectrometer. Likewise, a series of ten nitrates was examined in the rock salt region with this same instrument in order to fix the

Intensity

The purities of the samples are indicated in the legends for the curves.

Many of them show weak remnants of the carbon dioxide bands near 4.3 and 14.8 microns. The latter always appears as a sharp upward pip. Many of the curves exhibit a drop in transmission near 15 microns and then a small increase beginning at 15.5 microns. The initial decrease is due to the absorption by the sodium chloride plates, which was not compensated in the reference beam. The reason for the later increase is not known, but it is not real. It has the effect of suggesting an incorrect position for bands near

Some idiosyncrasies of the curves warrant mention.

Table 111. Infrared Bands of Various Nitrates (Cm.- m, s p a w m, sp w VS S S

. . , . 836 . . 1358 824 . . 1380

733 803 835 1318 , . . . 820 1044 (1359) (

737 . . 815 . . 1387 729 . . 817 . . 1352 . . 835 . . 1361 . . (807) 836 . , 1372

836 . . 1378 726 807 836 . . 1373

. . . . , . . .

1430) ( l i i 0 ,

, . . . (1640) i6ij 1441 . . 1418

. . . . 1587 . .

, .

V S

1790 1767

. . 1795 1774

(1785)

1790

v w

2428

2 i i o (2410)

2431 . .

wave lengths of absorption more Bands >3000 cm.-L are omitted. ( a w, ni, s = weak, medium, strong. g p = sharp. v = very.

) Baird values, less accurate. accurately. No attempt was made to put

the spectra on a quantitative basis.

RESULTS 16 microns. For example, in ferrous sulfate heptahydrate ( S o . 91) the curve indicates a band a t 650 cm.-l (15.5 microns), but actually it is a t 611 ern.-' (16.5 microns).

The spectra are presented a t the end of this paper. Table I lists the compounds examined and gives the numbers of the corresponding spectral curves. Table I1 summarizes the positions of the bands in wave numbers and in microns, and gives estimated DISCUSSION OF RESULTS

peak intensities. If more precise wave numbers have been determined with the Perkin Elmer spectrometer, they are used. Asterisks indicate those compounds examined in the potassium bromide region.

Nujol bands are marked with asterisks; portions of curves run in fluorolube are indicated by an F. The spectra of Nujol and fluorolube are included for comparison (No. 160). In a few cases the ponder was used without a mulling agent; these are indicated by P.

The spectra themselves are shown in graphical form.

The spectra range in quality from surprisingly good ones, with sharp, intense bands (see curves for barium thiocyanate dihydrate, No. 28; strontium nitrate, No. 44; and ammonium hexanitratocerate, No. 157,) to very poorly defined ones such as those for potassium silicate, So. 32; monobasic magnesium phosphate, No. 69; and monobasic potassium orthoarsenate, KO. 75. I t seems to be characteristic of the phosphates, and especially of their monobasic and dibasic modifications, to have ill-defined spectra. The reason for this is not clear, but it may

be due to lack of a single, well-ordered crystal c rn-1 structure.

Effect of Varying Positive Ion. One of the purposes of this study was to ascertain whether the various ions have useful characteristic frequencies. It was therefore of interest to know the effect of altering the positive ion. The spectra of ten SUI- fates are shown in Figure 1 in the form of a line graph. I t is seen that two characteristic frequencies occur, one a t 610 to 680 em.-' (m) and the other a t 1080 to 1130 cm.-l (s). There is enough variation between the individual sulfates so that it is often possible to distinguish between them from the exact positions of the bands. Table I11 presents similar data for ten nitrates. Again there are characteristic frequencies, a t 815 to 840 cm.-' (m) and 1350 to 1380 (vs). The authors

tween the positions of these nitrate bands and a

mass. This is not surprising, for there are a t least

I have been unable to find any orderly relation be-

property of the positive ion, such as its charge or

three reasons why a frequency may shift slightly as the kind of positive ion is changed.

M n S O 4 . 2 W

Z r S O 4 . 4 W

C r S 04' K2S 04

I I

I I1 . I

The different charges and radii of the various positive ions produce different electrical fields in the various salts. These doubtless affect the vi-

W. Water brational frequencies of the negative ions. sh . Shoulder (Continued on page 1298)

2 4 W

Figure 1. Comparison of Infrared Spectra of Ten Sulfates

vh. Very broad


IW

10

I W /4n I I I I ,

Sodium metaborste, NaBOz

C.P. = bo

z

40

20

0 2 4

, 5 W I , W I I W I200 l i W Iwo 9w aw 700 b2S WAVE NUMBERS IN CMI WAVE NUMBER5 IN CM'

500) Urn low 2SW ?OW

F A~ ~ \ ~ I; i f~ ~ ~

~ , J ~ I 1 \;Z$U: I

' 0 I

5 6 I 8 7 10 I1 12 I 1 I 4 1s WAVE LENGlH IN MICRONS

Magnesium metaborate, Mg(BOz)z.SH:O

C.P.

2 1 4 5 b 7 I 9 I O 1 1 12 I 1 I4 IS I 6 WAVE LENGTH IN MICRONS WAVE LENGTH IN MICRONS

Ism ,104 I1W I100 I I W Iwo 9w I00 7w b2S WAVE NUMBERS IN CM' WAVE NUMBERS IN CM

5wo Urn 100) 2100 lwa lM 100

I O IO

5 6 0 bO

3 g * z

40

z 20 20

0 0 2 I 4 5 6 7 8 P I O I, I1 I 1 I 4 I S I 6

WAVE LENGTH IH MICRONS WAVE LENGTH IN MICRONS

WAVE LENGTH IN MICRONS WAVE LENGTH IN MICRONS

Lead metaborate, Pb(BOdn.Hz0

C.P

Sodium tetraborate, Na2BO. 10Hz0

C.P.

, 5 W l , W 1100 I I W l l W Iwa 9W ud 7w 625 WAVE NUMBERS IN CM1 WAVE NUMIRS IN CH

500) (ooo 100) 2Mo low

Potassium tetraborate IM

KgBdO?.5HzO I O

c P. i z *

1"

z e

: 20

0 WAVE LENGlH IH MlCRMlS WAVE LENGTH IH MICRONS

V O L U M E 24 , NO. 8, A U G U S T 1952 1261

1 I I " 6'*

I W

I 80 . 10

Manganese tptraborate, MuB4&.8HzO

I! I I I j

1 1 1 E i r Z b Q

f, '0. Y

, z

L'

~

20 v ' I 1 I 1

0 '

C.P.

M)

*

i lo

0 I.

Sodium perborate, ?;aBOa.lHdI

C.P.

I 4 5 b 7

Boric acid, HiBO

0 2 .

8 V 10 I I 11 I1 I4 I5

Boron nitride, B N

Pure

IW. I '1'" 'I 10 Y l V "

Lithium carbonate, LizCOa

AR

I O

s 5 60/ * I r I I \AIL ~ I

I j lh/--, (0

* E'O s IO

0

l a / ! I I \ l /* 1 ~ I ~ : L / ; I 10 1 1 I

I 1 1 ~ I l l I 0

6 7 I V 10 I1 I1 I1 I4 I 5 Ib

IIW l u x ) 1100 I l W l i W loo0 9w 10) 7m SVX 4oW 1VX ZSW 1VX 100.

9 r

Y IO .

/ / -

< F ! ' * '- p7f z u I L c

I I

Y I 1 ~

c 'Ob

I Y 10 . 1 1

~ / I 1 I Q ' I

1 4 5 b 7 I 9 10 1 1 I1 I I4 I 5 J

615 loo

m

M

*

10

Ib

I5W l u x ) 1lW 1100 1100 IVX (w iw 700

-#-- - 1'0

1 0 0 . '

10.

H F I i I \,

I V f a -

u

zi

~

i * -

1 8 9 0 I I1 I 1 I I S

615

I O

64

40

l o

Ib 0


1 5 w 1 4 c a 1100 i i c o ) l o o iom FCO 6CC 100 b l i WAVE hLM5ERS Ih C U I WAYL NUM?ERS IN C M '

5ccO wO 3 w 0 15W lw(.

I S W i l W I I W I700 l l 0 0 IOW 9w IM IW 5wO u40 1wO 2m 1004

I IW 3 15Im r

80 -7

I J ! - -80

" ~

5 . f I

* I 1-1 ~--- 1"

Y !

10

b 4 1 1 5 L 1 I V 0 I I 1 I 1 I 5

WAVE LENGTH IN MICRONS WAVE LENGTH IN W C R M I S

Sodium carbonate, NazCOi

b15

Y

10

10

b 0

AR

Potassium carbonate, KnCOi

AR

Magnesium carbonate, basic, 3MgC.01- Mg(OH)n.aHnO

Unk

Calcium carbonate, CaCOa

AR

Barium carbonate. BaCO:

A R

V O L U M E 24 , NO. 8, A U G U S T 1 9 5 2

WAVE NUMlfRS IN u ( l WAVE NUMBERS IN C M ' 5 io0

W

m

1 1 5 b I I 11 I1 I1 14 16 0

l b WAVE LENGW IN MICRONS WAVf LfNOTH IN MICRONS

Cobaltous carbonate, COCOl

Unk.

I ,263

Lead carbonate, PbCOj

Unk.

Ammonium bicarbonate NHiHCOa

Sodium bicarbonate, NaHCOa

C.P.

Potassium bicarbonate, KHCOI

C.P.


I I I W

i

I 'Na,CO. k.

I P

20

0 I I

80

- W

40

20

0

I O

IW1

s f M

E c 2 E "

10

0

Sodium cyanide, NaCN

I 1 '

2 5 1 m I - 7

\ mPY- I,/ I I I \ 80

" 1 'D

F

10

I 1 1 10

0

NaaCO3 impuritg

1 1 8 e 10 I I I I1 14 ' WAVE LENGTH IN' MICRONS WAVE LENGTH IN MICRONS

Potassium cyanide KCN

5 Ib

IlHCOa and K:COa impurities

Potassium cyanate, KOCN

Considerable KHCO impurity

Silver cyanate, AgOCN

"Higheat purity '

Ammonium thiocyanate, NHaSCN

A R

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1265

WAVE NUMIIERS IN CM ISW I4W I I W 12w I W Iwo 9w 8W I W b25

WAVE NUMBERS IN CM' XCC Urn 3wO 1SW 3000

IW 100

IO (0

i M (0

f e

5" 4

$ 10 20

0 0 1 3 1 5 h 7 1 V I O I! I 2 I 3 I 4 l b

WAVE UN6TH IN MICRONS WAVf LENGTH IN MICRONS

WAVE NUMBERS IN CM WAVE NUMOERS IN CM1 sox 4ccc 3mo 25w 2000 I5W l4W l3W 17W W IWO Vw 8W 703 bl5

lW lW

(0 m 1- (0

I " 4

Y

20 10

0 0 2 3 4 5 6 7 V 0 I t I3 I 4 15 Ih

WAVE ttNGrn IN M~CRONS W A S Wlli IN MICRONS

WAVE NUMBERS IN CM' 1503 I+W I I W I1W I w lax, 9w SOD 7 w hl5

WAVE NUUBERS IN CM' SWO 4wO IWO ISW lD00

lop 100-

I O m

3 k t 4

r m 4Q

n

<

v 20

0 0 1 I 5 L 7 V I O I 1 11 I S Ib I1 Ib

WAVE LENGTH IN MICRONS WAVE LEN6TH IN MICRONS

Sodium thiocyanate, SaECS

Potassium thiocyanate KBCS

A R

Barium th~ocyanate Ba(SCX):.2HzO

C.P.

Mercuric thiocyanate, Hg(SCS)*

Pure

Lead thiocyanate Pb(SCN)*

C.P.


Iyo 1 0 0 1 1 0 ) Irn Ilm la4 no 800 1W Xm u*yI 1800 1100 lOm

\ 33 IW

I I o . J rr-"---/

1 7 ?--

W *

I' I 1

L 1 * 8 " s

20

~

0 3 I I b 1 8 7 0 I1 I ll I+ I&

(11

w

W

44

20

0 Ib

WAVE NUMBERS IN CM WAVE NUMBERS IN CMI

WAVE U N 6 W IN MICRONS WAVE LM6W IN MICRONS

5 IW

H

44

10

0 4 2 I I 5 b 7 I * 0 II WAbl I uN6W IN I 3 MCRONS 4 It b

WAVE LWOM IN HICRM

Sodium metssilicate, NarSiOr5HaO

O.P.

Potassium nietrtsilicate, KrSiOi

O.P.

Sodium ~ i l i r o f l ~ ~ o r i d ~ , SazSiFe

a.p.

Silica gel, SiOmHrO

Sodirim nitrite, NaNOi

C.P.

V O L U M E 24, NO. 8, A U G U S T 1952 1267

37IW tm

' I MI -. /

Y \

/ w

WAVE NUMBERS IN CM I WAVI NUMBERS IN C U I 5

80

Y

a

20

0 2 1 5 6 7 I e I O II I 2 I1 I 4 I 5 Ib

WAVE LLNGTP IH H U M S WAVE ENOW IN mcRoNs

5 im

W

Y

20

* 2 I I 5 b 7 I I O I I 12 I> I 4 Ib

WAVE UNOIH m MICROHS WAVE LENOM IH MICRONS

3 L 1- f

I *

I 20 I

fi

* 2 I 4 5 6 7 e I O I 2

WAVE LENGTH IN

1 1 WAVE LEWTH IN UlCRONS

WAVE HUMBEIS IH C W WAVE NUMBERS IN CU

a

WAVf YHCM IN MICRONS

Y

I ~ l a

20

0 1 14 I 5 Ib WCRONS

Potassium nitrite, KXO,

C.P.

Mver nitrite, AgKOz

C.P.

Barium nitrite, Ba(N0:hHsO

C.P.

Animonium nitrate, NHaKOs

C . P

Sodium nitrate,

AR

KaNOa


W rn im , , 7 0 0 , 1100 l4M llm I lW l l00 IXd 5wO UDO 105) 2SW 2mO

60 1 ' // lP \wd lo '4 I z I z I

b o /

; 401

1 1

S '

g e *

10 I I

I 0

1 1 I 5 b 7 I 0 I 1 1 I I S

b25 loo

M

10

10

Ib *

Potassium nitrate, KSOa

A 11

Silver nitrate, AgSCs

C.P.

Calcium nitrate. Ca(Pi0dp

C.P

Strontium nitrate, Sr(XOd3

Unk.

WAVE WUMlERS N CM 5 100

(D

10

10

* 1 1 4 5 b 7 I 10 I t I1 I1 16 I C 1b

WAVE LENbTH H MICRON5 WAVE LEN6lV IH MICRMIS

Barium nitrate, B~.:(?jod?

A It

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2

100.

80 ~ *7-" ' ~ 4 9 3 - z b o -

- i' / I

z i t 4

P \ / p , 2 ~ i9 \r'

20 "

0 I 2 a V 0 I 2 I 3

1269

I W

no

4a

20

0 ' W A d LENGTH IH' MICRONS

Cuprio nitrate, Cu(XOi):.3H:O

C.P.

Cobaltous nitrate, CO (;203) 2.6 €I20

AR

Lead nitrate, Pb(XO3)

Ik I 5 I b WAVE LENGTH IN MURCUS

A R

Ferric nitrate, Fe(S03)3.9H20

AR

Bismuth subnitrate. BiOSO3.HnO

Unk.


IW

\ 80

I - " I

I s 5 / E M

1 51:

b4

Eodium phosphate, tribasic, NalP04.12H;O

\ f '0 I / F I ! ( 1

\J \ I Y I 1 10 1

AR

1 i '\I I

4a

20

Potassium phosphate. tribasic, &PO4

0~ I v 2 1 I I b 7 I t

WAM L W l H IN MICRONS

c. P

I l l 1 0

D I1 I 2 I 1 I 4 IS Ib WAVE LENGTH IN WCROHS

Magnesium phosphate, tribasic, Mga(POdyAHz0

80

3 - I a -

C.P.

5 M Mo( 3oW 2W W I w - ' I ( " ' , ' ' '

I i 52lw I 1 I , ;

v i I 10

* ! \ I I ji * \ \ / I ! j I I I

\ 40

Calcium phosphate, tribasic, Cas(PO4)r

lol L: j ~ 1: 0

*

r . e

IC/ I 2 0

I i I ' 0

I

Manganese phosphate, tribasic, Mni(POdp.7H10

2 I I 5 b 7

C.P.

8 e I O 1 1 I 2 I1 I* 15

I W

80

P g,

P g Z "

10

0

Ism lua I l W I2W I l W Imo (00 aw 700 b25 swo k4f8 1m 2100 zoo0

I I I 153r

I; I I I

' " . ! '

I

:i I ! ~1

J , I 8 O

? I b-, ' A /--..,

* I

f I i i ? ba

I I -$

4a

! I

t I

IO

V I * 0

2 3 I 5 b I WAVE LEN6TH IN MlCRMiS

8 . 0 I1 I 2 I 3 I b WAVE LENOW IN MICRONS

V O L U M E 24, NO. 8, A U G U S T 1952

I I I I 5 qoo

/-7. ir\ , 1.m, , ! I -

WAVf NUMBERS IN CM1 IW I- IIW IZW iim imp t W IN I W L I S

WAVE NUMltRS IN C M ' I m p m tmo 2100 I m a

/ * 1 ,

I I

* 1 i i 7 I /,

1271

I \ \, , I

I I

L,

I

I I

I ~ l I ;

I I

0

Nickel (ow) phosphate, tribasic, Nia(POdz.7 H?O

Copper(ic) phosphate, tribasic, Cut(POa)z.3H10

C P

WAVE NUMBERS IN CM' 9w IN 100 b15 15w Iuc 1100 Lm, l I W Iwo

WAYZ NUMBfRS H CM 5wO I W P ION 25W ZOW

58Iw I O I

I ? I '

I ~ i * 10

I

I 1 . 5 b 7 I V 0 I 12 I 1 I4 I 5 0

I b WAVE LENGTH IN MICRONS WAVf LENGTH IN HhROlll

WAVE NUMBERS IN CM 5 iw

(0

M

40

20

5 b I I V I O I 1 I1 I> I 4 0

I6 WAVf LENGTH IN MKRONS WAVf LfNGTH IN UICROM

Lead phosphate, tribasio, PbdPOdz

C.P.

Chromic phosphate, tribasic, CrPOc.Hn0

P.P.

Ammonium phosphate, dibaaio, (NHOrHPOt

C.P

1272 A N A L Y T I C A L CHEMISTRY

l 5 a IUD I1rn I 2 0 0 llrn Im, 100 700 b25 WAVE NUMDERS IN CUI WAW W W S IN CU-

100 100

S 80

U

E

I " P

4

n 10

I I I I I W I I I 1 I I I 1 4 5 b 1 8 * 10 I 1 I2 I 1 I4 I 5 I b

WAVr W T H IN UCRONS WAVr LW6W IN MICRONS

(0

E M

f o 4 F

20

0

WAYS W T H IN MKRONS WAVE ENSW IN UCRCUS

WAVE NUMBERS IN CUI WAYS NUMBERS IN CU I w urn 1m 2 x 0 2wo 5

ID3 Irn

10 m

j M f P

Lo

5" 4

10 20

0 2 1 5 6 I 8 * I O II 12 I1 I4 I 5

0 I b

WAVE UNSW IN UKROM WAVE LENGTH IN MICRONS

WAVE NUMllRS IN CUI

1 a 4 5 b 7 8 * I O I 1 I1 t i I 4 I 5 I b WAVr LBTW N W W WAVE LWSM IN MICRONS

Sodium phosphate, dibasic, NaSHPO 1.12 H20

C.P.

Potassium phosphate, dibasic, K~IIPCI

C.P.

llagnesium phosphate, dibasic, MgHPOa.3HzO

C.P

Calcium phosphate, dibasic. CaHP04.2H20

C.P

Barium phosphate. dibasic, BaHPOi

C.P.

V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2

I W

I O

kb3 n

5 F 5 a - 8 t

20

0

1273

67lW ~

ao

1 w

lJ In v -v'd 1 ~- a

I F I

I I 1

I 20

I 0 2

Sodium phosihate, monobasic, KaH1POd.HsO

I . 5 L 7 I 9 i 0

C.P

IW

I O

P 2 5" z

ia 20

0

I lW

6 8 ~ Potassium phobphate, 1 1 monobasic KHlPOl \ I

I - - 1

C P I I b O

I * \J .-

I I I i*) *

1 I

10

0

I

0 2 I 4 6 b 7 8 I D I 1 I 2 I 3 I 4 I S

WAVI W ? H IN MICRONS W A X M O T H W MICRONS

2 3 4 I b 1 8 v 0 I t 2 WAVE UNSTH IN WAVE UNOTH IN *UCRON5

.\Iagnesium phosphate monohaeic, 3Ig(HzPO&

3 MICROM I4 16 I b

C . P .

.\Iagnesium phosphate monohaeic, 3Ig(HzPO&

c P.

2 I 4 6 b 7 8 I D I 1 I 2 I 3 I 4 I S I b WAVI W ? H IN MICRONS W A X M O T H W MICRONS

Calcium phosphate, monobasic, Ca(H?P03~.HrO

.\ R


I IWW( I 1

to

Sodium rnetaaraenite, YaAsOe

I I

l,

1 3 4 5 b 7 I I I D I WAVf LfNGTH IN MICRONS

A R

I i 72O0

M

4a

\ / f / XI

0 12 I1 I 4 I S Ib

WAVE LLNGTH IN MICRONS

Calciuni orthoarhenate, tribasic, Cas(AsOd2

C.P.

Fodiuni orthoarsenate. di- haiic, Na:HAsO~.iH,O

Unk.

Lead orthoaraenato, dibasic. P ~ H A s O I

C.P.

Sm 1 1 0 ) ,100 I lm llm Imp 9m UD 7m bZS WAM NUHIILRS IN C H I WAVE NUMPfRS IN CM

X 4 8 1000 *Dp 2100 IWO

Im Potawurn orthoarsenate, inonohasic, KH14a04

iR M

4a

m

0 2 3 4 5 6 7 8 10 I 2 I 3 I 4 I 6 Ib II

WAVE LfN6lH IN HKRONS WAVE LENGTH IN MICRONS

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1275

Arsenic trioxide, .-\sr03

Vnk.

Yodirirn


Potassium sulfite. K?S0!.2H?0

r I,

Calcium sulfite, CaSOi.2H20

C.P.

Barium sulfite, BaSOi

C.P.

Zinc sulfite, ZnSOa.2HnO

C.P

Ammonium sulfate, (NHWOd

Unk.

1277

Sodiuiii sulfate, Xa?SOd

AR

Potawlurn sulfate, lid304

A R

Calcium sulfate CnS04.2H20

A R

XIangnn-e aiilfare, JInSOc2HzO

C.P.


i I BO

~

, ~

d

Ziroonium sulfate, ZrEOi,4H?O

C.P.

, I

Chroiniu~n potassium ralfare, CI.E(SOI)J.- l i rR0~.24H:O

, I 20

Unk.

I rJ I I I I * ~ j o i ~ I j i ~

I 1 1 5 6 7 I 9 I O I , 12 13

Ammonium bisulfate, NH4HSOl

0 k 15 Ib

C.P

I O

f i i ! * I 110

\ g i 5 b o ; I ~ __r

I bo

I ,I i f~ ' _ ,

z l ; j ~I i : j" i 5 10

J

20- ! . I i * : I o l I 1 1 5 b 7 V 0 I1

WAM tEwm IN MICRONS WAVE

i , "0

1 I IC

I 1 I

I , I I, I 5 I 6 LENGTH UI UICRONS

1 0

V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2 1279

Sodium biaulfate, XaHSOI

A K

Potassium bierilfate. KHSOI

A R

Aiiiruoniurii thiosrilfate (N €i,)..S2OI

C.P

Sodium thiobulfatr, xa:S*03.5H?o

.I R

Potassium thioniilfntr, KnSrOa.Hr0

C.P


IW,

I O

4 1

E 5 10

I H D i H i O ,IS0 l1W i l W two PW BOO 700 b2S WAM NUMBERS IN CM WAVE NUMBERS IN CM

I1100 k1100 31100 I H D 2Wa

I IW I

IW

I

I

-

I

V I , 1

! b o 7 A 1~ ~

'il , i * i 20 + \

I I j

Magnesium thiosulfate, hlgS20a.6H10

m

O

C.P.

4 5 b 1 8 P 0 I I I1

Barium thiosrilfatr, Be&Oa.H>O

I I 4 I5 Ib

C.P

Sodium ~netahisrilfite, Wa?PtOs

Potassium nietittiisuifite, Ii2SnOr

A R

Arnmoniuni persillfate. ( N H I ) ? S ~ O ~

.IR

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1281

IW

I i I 'I 08Im Y * ? A Y I

\

5 M A z

t

\

Potassium persulfata, KnStOs

C.P.

(0

a

Sodiiini

\ / I ~ I I

5 40 I ~

$ 1 , 20.

I i I I

0 I

selenite,

P t iye

, \

4

I

\/ 20

0 I

Copper selenite, CuSeOL2HZ0

1 I 5 b 7 8 V 0 I I I 2 I3 I 4 I S I 6

Vnk.

Pl'alSeOd

Sodium selenate, SazSe04.10H~O

C . P .


b% WAM NUHBERS IN CM' WAVE NUUlKRS IN C M '

rKa urn m a 1XD mo ,Cd 100

80 W

60

4

10 20

0 1 1 4 5 b 7 8 I O I 1 I1 I 3 I 4 I 5 I b

0

WAM LENCTH W MICRONS WAM LENSTH IN MICRONS

Potassium Belenate, KzSeOi

C.P.

Copper selenate, CuSeOc5HzO

C.P.

Sodiuiii chlorate, l iaCl01

AR

Potassium chlorate, KClOa

AR

Barium chlorate. Ba(C10a)z.HaO

C.P.

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1283

IW 1

I O p?, f"" 1 1

WAVE N V H l E R S IN C U ' W A S NUMBERS IN CMI 5 IW

80

M

4c

20

2 3 I 5 6 I I O II I 2 I 3 I 4 I 6 16 7 . 0

WAM LLHSTH IN MICRONS WAVE LENOTH IN MICRONS

I \n,.L'-\, & *

s $ * 2 $10 8 L

10

0

lrm 14w lrn 1100 11m Iom m 10) 5mo UC4 ImO I= 2mO

',ii 1 1 11 ;;r I I

i I I LJ

x

t

L . P .

ym urn 3om 2 5 0 ) 1w- ?

80

!

5 b0 n I # 2 Z W I

?r IO , Y

0

I

A R

)IS 150) 14w 13W la I l W ImO sw 8W 7w 2om 1 , I l l , I l l , , ,

d i I IS '* >!. I I j : / 80

i I \, 1 l ~ ! ! d *

z I bo

' I 1 I- ; !+I20

0 1

2 3 I S b 7 I 9 0 1 1 I 2 I1 I4 I S Ib

10'

I W

P

I -lW

V /?\ nf 1 1 1191 10

I

r rL /

I I

I / I I I

I , I /* h ,

I I 111 1

10 i 87 ' . Z W 2

1 1

0

I \ i 1 1 [ I M g d 1 0 4 ~ 1 I - ' 10

\L r' 1 -+*20

I I I I

I I

l o 2 3 4 S b 7 9 0 I 1 2 I 3 I+ I S I b

A N A L Y T I C A L C H E M I S T R Y

10

0

I I 9

0

Potassium bromate, KBrOa

I

h R

I 4 6 b I 7 0 I 1 1 I I, I S Ib

Silver bromate, AgBrOi

C.P.

Sodium iodate, KaIOz

C.P.

Potasaium iodate. KIOi

Unk.

Calcium iodate, CaIOa.BHz0

O.P.

V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2 1285

Potassium periodate, KIO4

C.P.

.4mmonium metnvana. date, NHcVO:

c. P

Sodiurn rnetavunadate. SnVOz.IHr0

Sodium chromate. KaL'rO4


IUD ,100 1100 I200 1100 ImO wo 800 1m b2S WAVE NUMBERS IN CM' WAVf NUMBERS M CM'

ym urn 3m0 I s m ZmO Im

z ! * - 5 *

i

20

0

I \ I IW

' V rl I-$ I I O

I + ;

I \\ P, / / J

I I

rA I * W

~

9,'

I O

I I

10

* I W ' I 0

Potassium chroinate , KnCrO4

I 3 4 5 b 7 8 I I O ,I I1

l l agne j iun i chroniate, M g C r O ~ . i H ~ O

I I 4 I 5 I b

f i i i i i I \ I I 1 10

C.P.

Barium ciironiate, BaCrOa

C.P.

Zinc rhromate. ZnCr04.7IipO

C.P.

1m WAVf NUHIERS IN CMl

pm 8W WAM NUMBERS IN CM'

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2

I

I I

1287

136 M

I

1 I 1 S

I - /I ,I

I IO

', 1 3 , 5 1 7 8 t 0 , I I, 4 I 5

WAVE W T H IN MICRONS WAVE LENGTH IN MICRCUS

oI

b15 WAVE HUMERI IN W1

IUD 1100 i im im i i w ID^ ua m 700 WAVE NUMBERS H W'

u y x ) u D o m n m laa im IC4

M W

i fbQ M

;;" 40

: Y

20 m

0 0 I 3 . 5 b 7 8 9 I O I 1 I1 I 3 I 4 IS Ib

WAVE UNOW IN I ~ O N S WAVE LEMGTH IN MKROM

IUD iua i im IIW itw imo 9m em 7m bl5 WAVE NUMDERS IN C M ' WAyt NUMlERS IN C Y '

row urn nm IUD Imo

0 b

Aluminiini chromate, Alz(CrO4) i

C.P.

im

10

< z

Ammoniuni dichroniate, (XHi)zCrSO;

I

1 I 37' 80

~

I 1 C.P.

IUD lua 110 I lm I l W lmo Ho em 7m W r ( 0 m>YE nm

I i : \, !/ S I f I F j d i I ll I ~~ ~ I \ \ r $ 'V

10 1 ,VI I I 1 I

I 0

3 . 5 b 7 8 7 I O I 1 I1 I 3 I 4 I S WAVE LINGTH IN MKlOHS WAVE LENGTH m WCROHS

Sodium dichroinate, NatCrtO; .2 € 1 2 0

625

S

40

m

0 b

C.P

100

I O

i M I

Potassium dichromate. K~CTSOT

L-nk.

- I \

I38 '

!\! ! / [ -c

W

- - 1 -

7T \ / I d I Y I rl t

Calcirini dichromate. CaCrzO;.SHrO

C.P.

!/ , 1

I 20

I * I , 0 .

1 I O I Y * I I 1

I 4 5 b 7 8 * 10 I 1 I1 WAVE LINGW m WRONS WAVE LENGTH IN MKROHS

44

i i'L 1 - m I V 0

2 I 5 b 7 I 9 0 II I I1 I4 I WAVE W T H IN MICRONS WAVE LEN6TH IN MKRONS

I b


IW

110

P i

~ ~ I4 I I I S

A M 1 m~ I

5 " \ r $ 1 I

10 I

I I I I I I

0

WAVE NUMBfRS IN CM' 5 lm

(0

M

10

0 1 I I 5 b 7 D . ,I WAVE I 1 LEN6TH 111 11 MKRONI I. I 5 Ib

WAVE LEN6M IN MICRONS

4a

I IO

1 0

Copuer dichromate, C uCr& .S H 2 0

1 I 4 S b 7 I 9 10 I / , I I

i P.

. I 5 I b

>odium molybdate. S a A f o 0 ~ 2 H z O

Iopdurn l u d m lwo Iffl - 2 I 43:Im M A T I

I

I i ~

* I /

P

2 Z"

$ @ !~

\ i f

20 Y : 1 I \J

P I

I O

~

1 I 4 S b 8 9 0 , I 1 I1 I, I S W A E W T H M U C R O N S WAVE LENOlH IN W C U S

.4 R

M

P

10

' 1 0

l o b

Potassium molybdate, KzMoo4.mo

\ /

/

F

I."-

5 M - ,pf, J ' U x s

C.P.

,4z W

-

.4 m nion I u ni he1)tamolybdate ~ N H ~ ) s ~ I o ; O u . 4 H i O

3 I " I

10

0 1 1 4 5 b 7 8 V I O !

WAVE WAVE LENOM IN MICRONS

.1 R

4

10

0 1 1 I. I 5 I6 LENOW IN WCRONS

Sodium tungstatr, S ~ ~ W O L ~ I I I O

c P.

1289

Potassium tungstate KzWO4

C.P

Calcium tungstate Caw04

Pure

WAY€ WMERS IN CMI 15% I100 I1W IM I I W Iwp em 800 7m '15

WAVE NUMIIERS IN C M '

.. I I

I48 ' -,i \ ,~ ~,-..-- I 4

', ~ ? bo

' " i , : 1 I ; 10 * ,

f i - W

I 0 1

1 3 4 5 6 7 I 9 I O I I 2 I 3 I 4 0 15 b WAVE LENGTH IN MICRONS WA- W l H IN Y C I C U S

W A M NWlERS IN W-l WAVE NUMlElS vi CM' yxxl UD) Mm 1m 2mo lxx) lux) llm ,100 I I W Imo .m 8rn 7m b25

im IW

10

E 5

4

5

I4

= 60 M

- 40

P 10

10 20

0 1 4 5 b 7 8 1 , 11 11 I. I 5

0 Ib WAVf LEN6TH IN MICRMIS W A M LWOTH IN MICRONS

Sodium permanganate. NaMnOc3HzO

C.P

Potassium permanganate, KhlnOi

A R

Calcium permanganate, Ca(MnOa)z.4Hn0

C P


Im

10

f E M

E f 5 *

IO

0

sbx rom rn 15m 2rm I

I I 54 '

I -

\ 110

n I \, 4 i~ I I I

60

I J * I

I J I I

, I 10

I

I

IO

I l I O

I 4 5 b 7 I 9 0 I I1 , I I, I5 Ib

Bariuui permanganate Ra(3lnOi)z

C.P.

Sodium ferroeyanide, SaiFe(CN)s.lOH.O

C.P

Potas.ium ferrocyanide, KqFe(CX"i).3I1~0

h K

Ca!cium ferrocyanide, CarFe(CN)s.l2H>O

Pure

Potassium ferricyanide, KsFe(CN)s

AR

V O L U M E 24, NO. 8, A U G U S T 1 9 5 2 1291

VW aw 7W 615 WAVE NUMBERS IN C M '

1x4 I r n I1W I I W I I W lca WAVE NUMBERS IN CM1

5WO I M o 1wP 2 x 4 1wP

f- ~ I r-\ 157Iw

I

I 1 1

I

I I

I

I I i - I

Sodiuiii coliultiriitritr NarCo i SO.!*

I LO

1 'e

.% K

1 -

AR

~ 10

Barium chluride, BaC12.2H10

.i R


Table IV. Use of Infrared Spectra in Qualitative Anal>-sis Final

Independrnt dnaly-e . Cornbined 1.0 Eniiwion Infrared X-ray rinalysis

1 Sa SaHCOi I.; Ca

.I I Silica gel

4T14SOI NH4NO.I Very poor pattern SO,---

Silica eel

B Ph A I

x Na ICKr20; Sothing K*CI.yOi Yellon K N a S C S or N H i K S Very poor pa t t e rn NaSCN

Cr Ifp(cloi)? AIg(ClO,)? " Sulfide odor Pb 1 Ph Y

4 Cd SiL?HlOi SatBaO; IOtLO NazBIO; 10H?O

B SaBiOx '! S a ') c ? P

I'ellon- Bi CdS CdS

.\IO K*S?O6 Ca CaCOa I.; PhCrO4 Sa '? KazSOr Y Sr 11

Sh Caar PO, I 2 Si P c a C P? Ba Na I. .11 ? SI. ? 7

KaI.03 B a ( K 0 s A nitrate; prohahly Ba- PhSOI '?

isos)?. possibly SaSOz Other component(s) Possibilities: Another ni-

trate, SaBrOl. Sa?WO, or K?\VOi. S a l l o O , or K l l o O ~

Changing the positive ion may produce a different crystallin? arrangement, resulting in a different symmetry or iiitensity of the electrical field around a negative ion.

A difference in t,he type or extent of hydration probably alters some of the frequencies.

011 the other hand Hunt, J\-isherd, and Bonham ( 5 ) found that for anhydrous carbonates there is an approximately linear relationship between the wave length of the 11- to 12-micron band and the logarithm of the mass of the positive ion(s). Hunt has kindly pointed out that, the authors' data tit his curve, with the exception of lit,hium carbonate.

Characteristic Frequencies of Inorganic Ions. Just as with sulfates and nitrates, most other polyatomic ions exhibit characteristic frequencies. These are summarized in Figure 2. It is evident that they are distinctive and that they do not have a great spread in wave numbers.

The usefulness of these charactei,istic frequencies in qualitative analysis is obvious. It appeared that the infrared spectrum might give, rapidly and easily, some information about the polyatomic ionE that are present in an unknoivn inorganic mixture. If only one or two compounds are involved, it might, even be possible to narrow the possibilities to a fex- specific salts. It also seemed that a combination of infrared, emission, and x-ray analysis might be very effective. Presumably emission analysis would determine the metals, infrared would say something about the polyatomic ions, and x-ray analysis might, give their combinat,ion into specific salts.

Qualitative Analysis.

Actual Composition

WaHCOi CaCOr K S O i

KilCrzOi S-aSCX RSCS CaS0. L H j O

To explore this possibility, u series of eight synthetic mixtures wa? prepared and analyzed in- dependently by the three techniques. ( A photographic x-ra!. procedure was used.) This iri- formation was then pooled, thr data were re-esamined, and ii

combined analysis was obtained. The test was not completel!- fair because it, was known that infrared spectra have been oh- tained for nearly all the inorganic salts in the laboratory, and that t'hese same salts would he used in making up the mixtures. In addition, t,he components n-ere mixed in roughly equ:il amounts by bulk.

The results are shoa-n in Table IT'. The analysis of misture 3 is discussed in greater detail below. I t is apparent that no one of the techniques by itself is powerful enough to give a complete analysis of even these idealized unknoums. This is partl)- because there was no prior information about the caontent of the samples, and therefore every possibility had to be considered. -1s xith any other anal) much more detailed and reliahlr

Cm-1 600 700 800 900 !OW 1100 1200 1300 1400

-21 s Z Y - 8 BO; 3

840: 3 ¶ c c o j a -

nco; 3 + SCN' *A

L l

- L

SILICATES 1 N N O i 4

NO: I I

NH; 17

HPOq 6 H PO' 5

5 SO; 6 1

P Po: 9

2. 4

soq I O A nso; 3 s20g 5

A , * s - I

s 2 0 j 2 i L -

I

s z o i 2 - k * L P

se sao; 2 li -1- s*o; 1

c uo; 3 C l O i 4

I lo; 3 v v o j 2

c, c,o; 8 , G o= 5 E . !

w wo; 3 A

Br Br 0; 3

No h b o i 2

Mn MnOZ 4

600 700 800 900 1000 1100 IPW 1300 1400

Figure 2. Characteristic Frequencies of Polyatomic Inorganic Ions s. m, w. sp. Sharp ** Literature value

Strong, medium, weak * In most, but not all, examples

V O L U M E 2 4 , NO. 8, A U G U S T 1 9 5 2 1293

results can be obtained if there is some advance information ahout the nature of the unknowns. However, Table I\- also shoTvL: that the three techniques are nicely complementary, and th:it together they are capable of providing a considerable amount of information even when such prior knowledge is lacking. Al- though thrre are two or three surprising errors in the combined :inaI?ws, the over-all rwults are verj- encouraging. It is espe- c-iall:. noteworth>- that the actual chemical compounds are giveir iri miny ca.vs.

tain possibilities for the x-ray analysis which greatly simplify its interpretation.

The advantages of this physical analysis include small sampk requirement, reasonable time, and the ability to determine the actual compounds in man>- cases. I t is evident, too, t'hat any or all of these three techniques are valuable preliminaries to a ishemica1 analyis on an unknown material, especially a quantitative one.

It is not uncommon to find that the spectra of t,wo samples of the same com-

Variability of Spectra.

pound are somewhat different. There are several possible reasons for thin.

WAVE N U M B S IN CM.1 1 5 W 1 4 0 0 1100 1100 I I W 1000

IMP~RITIES. In the spectra of sodium cyanide, potassium cyanide, and potas-

~ y sium cyanate (Xos. 21, 22, 23) bands 2 have been marked that are plainly due to 60 5 the corresponding carbonates and bicar- 2 bonates.

= CRYSTAL ORIESTATIOX. It is well knonm that the spectra of anisotropic

y crystals depend on the orientation of 8 the sample. Consequently it is desirable

to have completely random orientation of the crystallites to avoid such effects. This is an additional rewon for grinding the sample very finely.

WAVE LENOTH IN MICRONS PoLnioRPmsai. Different crystalline forms of the same compound are often raDable of eshibitine slightly different

io

Lp--d 0 8 9 I O 1 1 12 I 3 I 4 I 5 Ib

Figure 3. Portion of Infrared Spectrum of Lead Sitrate

WAVE NUMBERS IN CM' 1200 1100 1000 900 800

I , t > -4 I

8 0 I O I I 12 I 3

WAVE LENGTH, 1.1

Figitre 1 . Znonialous H a n d in Unknown 3 I n v i e r \ c a w (:a301 .hould be w r i t t e n C a S 0 ~ . 2 A ? 0

I s i ) i \ - i i ) i . . i i , T i : i . i i s r u i I . > . S-I,:~?. :in;ilysis of a conipletely unknowi sani~)Ie I ~ ~ ~ i ~ o i r i i ~ ~ tiiffii.ult \vhi~11 thrr(J art' nlow than two coniponc~ntr. I t is not :i1)plii,:iI)lv t o noncrystallinc material.. ( r f . unknown 2 ) and runs into troul)lc \\-ith substances that gaiii 01' lose water of hydi,ation readily. In both c5ase.q infmred i i often a rcliable tool.

Suhstanc~es like metal osides, hytirosides, and sulfides gener- :illy h:ivcl no sharply defined infrared absorption from 2 to 10

i d e from possible water and 0-H bands. On the ot1rc.r y are often good samples for x-ray analysis (vf. cad-

mium sulfide in unknown 4). The principal fault with emission analysis is its great sensitivity :

it is frequently difficult to distinguish between major components :ind impurities. This fact arcounts for t,he surprising oversight 01 cdcium in unknoivn 2 , and tungsten in 8.

Infrared examination has advantages over wet chemistry for detecting the more unusual ions, such as BOz-, B407--, SzOs-- , and S?Os--, since these are not included in the usual schemes of

The proper sequence in using these techniques is the order The first two present rer- cniission, infrared, and then s-ray.

., . infrared spectra ( 2 1 1..

\ . A R Y I S G DXGREES OF HYDRATIOX.

Several esamples of variable spectra have been otiserved, lor Lvhirh the muse is not definitely knonn. Tn-o different samples of potassium metabisulfite, KzS206, were esaniincd, and proved to have different, patterns of band intensities in one region (see curve 104). In potassium carbonate there is a hand a t 880 cm- ' or a t 865 em.-', and in one spectrogram out of a total of ten hoth hands appear. There is no cleai correlation betwen position and water content.

It rompares the spectra of two lead nitrate samples, one prepared nornially with Sujol and one with very little Sujol. Differ- mces near 1300 rm.-l and 880 t o TOO cm-I are striking. This may be an orientation effect. X more baffling case of unexpected variation was ol)serveil

with unknon-n S o . 3. In analyzing this by infrared, calcium sulfate dihydrate was missed completely and magnesium per- cahlorate \\-as reported in its place. The reason is brought out in Figure 4. Pure calcium sulfate dihydrate has a single broad lmnd centered near 1140 cm.-' (8.8 microns), whereas in inis- ture 3 a strong doublet was observed a t 1080 and 1140 cni.-l Thtx origin of the doublet was puzzling berause no other ($om- poncnt of 3 but calcium sulfate has a band near here. Calcium sulfate dihydrate had been run as a Nujol mull and mixture 3 as a dry powder. Reversing each did not change their spectra. Then calcium sulfate dihydrate was mised with each of the other components in turn in the dry state, and the mixtures \wre es- :mined as Nujol mulls. It \vas found that the misture with

ium thiocyanate gave a doublet. \Tith sodium thio- rj-anate there was also a doublet, but it TI-as much less pronounced.

I t seems unlikely t,hat a chemical reaction between calcium sulfate dihydrate and potassium thiocyanate could account for these peculiar results, bemuse the materials are in the solid state. Two other possible causes are changes in crystal structure, presumably caused by changing the hydrate, and an orientation effect. The following observat,ions seem to rule out variable water content as a cause, and suggest the orientation effect.

Figure3 shows that the mode of preparation is important.

A calcium sulfate dihydratepotavsium thiocyanat'e mixture heated a t 170' C. for 3 days gave the two bands near 1100 em.-'

Only one band was found after the salt plates were separated and the mull e~posed t o air for an hour.

1294 A N A L Y T I C A L CHEMISTRY

is evidence that these are 0-H stretching frequencies of the hydroxyl groups attachrd to the rentral atom.

B.%RInf CHLORIDE. Several chlorides of the purely ionic type were examined to observe how the hands due to watcr of hydrat,ion varied. Among these was barium chloride dihydrate ( S o . 159). Surprisingly it has a strong band a t 700 cm.-', which )\-as totally unexpected but was c,onfirnied on a second sample. I t is not attributable to carbonate or bicmhonate, hut may tie due to a torsional motion of the w:itcr molecules in tlic lattice.

COMPLEX Ioss. The rliaracteristic. frequcncic:; carry over moderately wcll into roinplex ions-for exainple, pot ricyanitie has a band a t 2100 cm- l , and each of the rhree fer- rocyanides has one near 2010 cni-'. This is obviously thc stretching frequency of the C S - gi'oupj which in simplr ryanides is 2070 to 2080 c i n - '

Sickel hydroxide, fci~ic* oside, cadmium sulfide, and mercuric sulfide have no absorption in the rock salt rcgion aside from watcr mid hydroryl hands.

Other examples are shon.n in Tnl)le V. CoIiPoazrns WITH So ABSORPTIOS.

Another portion of the same heated mixture was esposetl to air under more humid conditions for an hour and then mulled in Nujol: two bands again resulted.

This mull was opened to the air for an additional half hour, and only one band was found.

\\-hen calcium sulfate dihydrate alone was heated overnight a t 170" C., three bands were found. The sulfate vibration absorb- ing near 1100 cni.-l is triply degenerate (12), and this may be a case of splitting of the degeneracy as a result of altering the crystal symmet'ry. Finally, potassium sulfate has exhibited a similar variability in this same band,

. ~ _-_

Table V. Characteristic Frequencies i n Complex Ions Complex Ion Simple Ion cm. - 1 cm. -1

Fe(CN)s- - - 2100 cs - 2070-80 Fe(CKjc---- -2010 C?i - 2070-80 F e ( C S ) s N O - - 2140 cs - 2070-80

1923 XO (gac) 1878 847

1336 1430

SOP 820-33 1235-80 1328-80

C e ( S 0 d s - - 745 S O , - i26-40 SO? 815-35 1080 1260 1420

. . . 13.40-80

1530

I t is much safer to base arguments on the identity of spectra than on their nonidentity. >lore empirical experience with the spectra of salts from many different' sources should improve t,his situation.

Miscellaneous Observations. AXOMALOUS DISPERSION A N U

CHRISTIAXSEN FILTER EFFECTS. These have been adequately described in the literature (5 , 9). Examples will be seen in the steep-sided band of magnesium carbonate a t 3 microns (No. 13), of sodium thiocyanate near 5 microns (No. 26), and of potassium ferricyanide near 5 microns ( S o . 155).

The sharpness of the \\-ater bands near 3 and 6 microns in sodium and magnesium perchlorate (Nos. 117, l lS) , and the high value of their 0-H stretching frequency ( >3500 cm.-I), are striking. Apparently t'here is very little hydrogen bonding in these salts. It, is interesting to note that animoniuni perchlorate (KO. 116), \vhicah forins no hydrate, has a high K-H stretching frequency. Other compounds with sharp water bands are barium chlorate (KO. 115) and 1)ai~iuni chloride (No. 159).

In bicarbonate there is a band a t 2500 to 2600 cni.-', in Iiisul- fate at 2300 to 2600 cm.-' (very broad), and in HPOI--, H2P04-, HAs04--, and HP;IsO4-at about 2300 em.-' (very broad). Their

WATER AXD HYDROXYL BAXDS.

ACLYO&LEl)(;\I E X 1

The authors are inciel)ted to two colleagues, D. T. P i t i i i x i i

and E. S. Hodge, for carrying out th r x-ray and emission analy- ses, respectively. Helen Golob prepared many of the curvrs . The Chemistry Departments of the University of Pittsburgh and Carnegie Institute of Technolog!- graciou3ly provided many of t,he samples.

LITERATURE CITED

Colthup, N. E., , I . Optical Soc 40 397 (lCJ50'. Glockler, G., Rec. M u d e r n I 'hys . , 15, 111 (1913). Hersberg. G., "Infrared and Raman Spectra of Polyatomic

(4) Hihhen, J. H., "The Ranian Effect and Its Chemical -ippIica- Molecules." Sew I-ork. D. Van Noatrand Co., 1945.

tions." S e w York. Reinhold Puhlishinrr Coru.. 1939. ( 5 ) Hunt, J . M., Wisherd. 11. P., and Ronhani, L. k. , .is\r., C H i c v . ,

(6) Lecomte. J., AM^. Chim. d c t n . 2, 727 (1948). (7) Lecomte, J.. C'ahiers p h y s . . 17, I (1943!, and referelives cited

(8) Sewman, It.. and €Idford, R. S.. .I. C'Aem. Phys.. 18, 1 2 i 6 , 1 9 1

(9) Price, TT. C.. and Tetlow, K. S. , I b i d . , 16, 1157 (194q).

22, 1478 (1950).

therein.

(1950'.

(10) Schaefer, C.. and Xlatossi, F.. "Das ultrarote Spektrum," Her- lin, Julius Springer., 18:30; repi.inted by Edwards Bi,os., Inc., Ann Arbor, l f i c h .

(11) \Vagner, E. L., and I-Ioi,nig, D. F., J . Chem. P h y s . . 18, 296, 305 (1950).

(12) Wu, Ta-You, "Vibrational Spectra and Structure of Poly- atomic Molecules," 2nd ed., .%nn .%I hor, Mich., J. W. ICcIwat ds. 1946.

RECEITED for review July 3 , 1931 .ici.epted J u n e 7 , 19z2

infrared spectra and characteristic frequencies of inorganic ions

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