ylide-metal complex to dryness and the residue was extracted with

8/14/2019 Ylide-Metal Complex to Dryness and the Residue Was Extracted With

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Ylide-Metal Complex Inorganic Chemistry, Vol. 15, No. 2 , 1976 417to dryness and the residue was extracted with 10-20 ml of ethadol.After evaporation of the ethanol, the solid that remained was checkedby infrared spectroscopy for the presence of perchlorate. If anyabsorption for the anion was present in the spectrum, the solid wasdissolved in 5-10 ml of water and passed over an anion-exchangecolumn (Dowex 1-X8, 100-200 mesh, CI- form). The eluent wasevaporated to dryness and the solid collected. All products, regardlessof origin, were dried in vacuo over P4010.

Acknowledgment. Acknowledgment is made to t he donorsof the Petroleum Research Fund, administered by theAmerican Chemical Society, for support of this research.

Registry No. 4, 57456-81-2; 5(C104)2, 57427-09-5; 5(c1)2,57379-16-5; 5(CN)C104,57379-18-7; 6,57379-20-1; 7, 57427-1 1-9;8, 57427 -13-1; 9, 57379-22-3; 10, 57379-24-5; 11, 57379-26-7; 12,55701-26-3; 13, 57379-28-9; 14, 39042-83-6; 15, 57379-30-3; 16,57456-82-3; 17(C104)2,57427-14-2; 17(C1)2, 57379-3 1-4; 17(CN)2,57427-15-3; 17(N3)2,57379-32-5; 17(SCN)2,57427-01-7;17(OCN)2,57378-95-7; 17(N?,)(H 20)(C10 4), 57427-74-4; (17)2(N3)3(1),52588-40-6; 18, 57378-97-9; 19, 57378-99-1; 20, 57379-01-8; 21,57379-03-0; 22, 57427-03-9; 23, 57379-05-2; 24, 57379-07-4; 25,57427-05-1; 26, 57379-09-6; 27, 57379-11-0; 28, 48175-68-4; 29,57427-07-3; 30, 57379-12-1; 31, 57379-13-2; 20(C1)2, 57379-14-3;21(C1)2, 57379-15-4; a,d -dib rom o-o- xyle ne, 91-1 3-4; N,N-di-benzylcyclam, 57325-55-0;A,-dibenzyl-A,-dimethylcyclam,57325-56-1: sodium methylsulfinylmethide, 32249-19-7; potassiumhydroxide, 1310-58-3.Supplementary Material Available: Table of analytical data andNMR spectra of N-alkylated complexes (9 pages). Ordering in-formation is given on any current masthead page.

References and Notes(1) E.K. Barefield and M. T. Mocella, Abstracts, 165th National Meetingof American Chemical Society, Dallas, Tex., April 1973,No. INOR139; . A m . Chem. Soc. 97, 238 (1975).(2) G . A. Kalligeros an d E. L. Blinn, Inorg. Chem., 1 1, 1145 (1972);L. L.Rusnak and R. B. Jordan, ibid., 10, 686 (1971).(3) E.K. arefield a nd F. Wagner, Inorg. Chem., 2, 2435 (1973).(4) (a ) R. Buxtorf, W. Steinmann, and T. A. Kaden, Chimiu,28, 19 (1974);(b) R. Buxtorf and T. A. Kaden, Helv. Chim. Acta, 57, 1035 (1974);

(c) L. Hertli and T. A. Kaden, ibid. , 57, 1328 (1974).(5) M. J. DAniello, Jr., M.T. Mocella, F. Wagner, E. K. Barefield, andI. C. Paul, J . Am. Chem. Soc., 97, 92 (1975).(6) B. Bosnich, M. L. Tobe, and G. A. W ebb, Inorg. Chem.,4 1102 (1965);B. Bosnich, R. Mason, P. Pauling, G . B. Robertson, and M. L. Tobe,Chem. Commun.,97 (1965).(7) L. G.Warner and D. H. Busch, J . A m . Chem.Soc.,91,4092 1969).(8) L. G.Warn er and D. H . Busch, Coordination Chemistry: PapersPresented in Honor of J. C. Bailar, Jr., Plenum Press, New York, N.Y.,1969, I .(9) D. K.Cabbiness and D. W. Margerum, J . A m . Chem. SOC., 2, 151(1970).(IO) L. F. Lindoy, Coord. Chem . Reu., 4,41 (1969).( 1 1 ) G . W. Watt and P. W. Alexander, Inorg. Chem., 7,537 (1968).(12) A preliminary account of part of this work has appeared : F. Wagner,M. T. Mocella, M. J. DAniello, Jr., A. H.-J. Wang, and E. K. Barefield,J . Am. Chem. Soc., 96, 2625 (1974).(13) F. Basolo and R. G. earson, Mechanisms of Inorganic Reactions,2nd ed, Wiley, New York, N.Y., 1967, 32.(14) G. W. Watt and D. H . Carter, Inorg. Chem., 7,2451 (1968).(15) C. P.Ritchie and R. E. Uschold, .I.m. Chem.SOC.,9, 730 (1967).(16) E.L.Blinn and D. H. Busch, Inorg. Chem., 7, 820 (1968).(17) Complexes 20,21, nd 22were prepared by the same procedure utilizedfor [Ni(cyclam)]2+ using the appropriate tetramine. See E. K. Barefield,Inorg. Chem., 11,2273 (1972). nd E.K. Barefield, F. Wagner, A. W.Herlinger, and A . R. Dahl, Inorg. Synrh., i n press, for the cyclamprocedure. A publication describing the preparations and properties ofthese complexes and others prepared by glyoxal condensation methodshas been submitted.(18) D. K. Cabbiness, Ph.D. Thesis, Purdue University, 1970. 2.3.2-tet is1,4,8,11tetraazaundecane.(19) F.Hinz, Ph .D. Thesis, Purdue University, 1973.(20) M. T.Mocella, Ph.D. Thesis, University of Illinois, 1974.(21) C. R. Sperati, Ph.D. Thesis, The Ohio State University, 1971.(22) E. M. Amett, Acc. Chem. Res., 6, 04 (1973).(23) W. . Perkin, J . Chem. Soc., 5 (1888).(24) N. F.Curtis, Coord. Chem. Reu., 3, 3 (1968).(25) (a) W. H. Elfring, Jr., Ph.D. Thesis, University of Washington. 1972;S. C. Cummings and R. E. Severs, Inorg. Chem.,9 1 3 (1970); (b )J. G.Martin and S. C. Cummings, ibid. , 12, 1477 (1973).(26) E. . Corey and M. Chaykovsky, J . Am. Chem. Soc., 84,866 1962);87, 1345 (1965).(27) Potassium hydroxide pellets were pulverized in a Waring blender . Cautionshould be exercised when handling this material as the dust is very irritatingto the eyes and nose. Mate rial thus prepared could be kept in a tightlysealed bottle for long periods of time.(28) TS P is sodium 3-trimethylsilylpropionate-2,2,3,3-d4.

Contribution from the Department of Applied Chemistry,Faculty of Engineering, Osaka University, Suita, Osaka 565, JapanThe Ylide-Metal Complex. Preparations and Structures of Palladium(I1)and Platinum(I1) Halide Complexes with Some PhenacylidesHIRO SHI KOEZUKA, GEN-ETSU MATSUBAYASHI, and TOSHIO TANAKAReceived July 28, I975 AIC505500

Platinum(I1) halide complexes of some phenacylides, ~- CH ~C SH ~N + -C H C( O )C ~H ~= Ny ), C H ~ ( C ~ H S ) ~ P + - C H C ( O ) C ~ H ~(=Py), (C~HS)~AS+-CHC(O)C~HS=Ay), and (CH3)2S+-CHC(O)C6H5 =Sy), were synthesized and their configurationselucidated on the basis of infrared and IH NM R spectra. The coupling constant between the 195Pt nucleus and the ylidemethine proton, 2J(Pt-CH), in tranr-PtClzLY ( L = PPhMe2, PMe3; Y = Ny, Py,Ay, Sy ) increases with inc reasing basicityof the ylide: Ny > Ay > Sy > Py. In trans-PtXz(PPhMe2)Y (X = C1, Br, I; Y = Ny, Py, Sy) , the V(Pt-CH) valuealso increases i n the order of CI < Br < I and at the same time the u(Pt-C) band moves to high frequencies. This resultis interpreted in terms of the interaction of the positively charged ylide heteroatom with halogen. Palladium(I1) ylide complexesPdC12LY (L = PPhMe2, PMe3; Y = Py, Ay, Sy) were also prepared and their structures a re discussed.

IntroductionYlide molecules differ from o ther organic ligands in tha tylides coordinate to metal ions as a neutral ligand to form au bond between the ylide carbon and th e metal atom. Thiswas shown by means of x-ray analyses of some ylide-metalcomplexes, in which the configuration of the ylide carbon istetrahedr al rathe r than planar.-3 Th e copper? silver,4 gold,snickel,6.7 and thallium8 com pound s of ylides are known to b ethermally stable an d th e stability has been ascribed to the roleof the onium center of th e ylide.7-9 Previo usly we rep orte dseveral stable palladium(l1) and platinum(I1) ylide com-

plexes.10 We attem pted to perform more systematic studieson the configurations of metal-ylide complexes and the in-teractions between metal ions and some phenacylides.This paper reports the preparative, infrared, and 1HN M Rstudies of palladium(I1) and platinum(I1) halide complexeswith some stable phenacylides as in+2- CHCCbH,II0

Z=P -CH ,Cs H,N (NY), CH,(C,H,)zP ( P Y ) ,(C,H,),As (AY), (CH,),S (SY)


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418 Inorganic Chemistry, Vol. 15 , No. 2, 1976Table I. Melting Points, Elemental Analyses, and Molecular Weights of the Ylide Complexes

Koezuka, Matsubayashi, and Tanaka~ ~~~ ~~ ~~ ~~% C %H % N Mol wta

Complex MP, O C Calcd Foun d Calcd Foun d Calcd Foun d Calcd Foundtrans-PtC1, (PPhMe ,)(Ny)trans-PtBr, PPhMe,)(Ny). /,CH,C1,trans-PtI, (PPhMe ,)(Ny). 1/,CH,Cl,btrans-PtC1, (PMe )(Ny)cis-PdCl,(PPhMe,)(Ay)PdCl, (FMe,)(Ay)Ctrans-PtC1, (PPhMe,)(Ay)trans-PtC1, (PMe,)(Ay)cis-PdCl,(PPhMe,)(Sy)cis-PdC1, (PMe,)(Sy)trans-PtC1, (PPhMe,)(Sy)cis-PtCl, (PPhMe,)(Sy)CHCl,trans-Pt Br, PPhMe ,)(Sy )cis-PtBr, (F'PhMe,)(Sy)CHCl,btrans-PtI, FPhMe, )(Sy)cis-PtI,(PPhMe,)(Sy)trans-PtCl,(PMe,)(Sy).1/zC6H6btrans-PdC1, (PPhMe,)(Py)trans-PdC1, (PMe,)(Py). H ,btrans-PtC1, (PPhMe,)(Py)trans-PtBr, (PPhMe ,)(Py)trans-PtI ,(PPhMe,)(Py)trans-PtC1, (PMe ,)(Py). 1/,C,H6

>165 dec>112 dec>97 dec179-182dec169-173dec171-173dec183-184dec169-171 dec176-177dec191-194dec>165.5 dec179-183 dec>155 dec172.5-175 dec151-153 dec150-153 dec170-173.5 dec107-110dec>178 dec>175 dec131-133dec

108-112

137-138

42.94 42.8236.19 36.5232.14 32.5536.90 36.8555.20 55.1751.39 51.3049.29 49.4345.45 45.2743.61 43.3236.01 35.9936.99 36.9532.43 32.8232.11 32.0528.79 28.9528.18 27.9828.18 27.8534.23 34.2954.96 54.4252.24 52.1448.21 47.7542.93 42.8838.47 38.3845.49 45.74

3.93 4.193.37 3.463.00 2.774.01 4.054.36 4.394.46 4.143.89 4.023.95 3.164.68 4.794.88 4.883.97 4.023.44 3.233.44 3.303.05 3.183.02 2.993.02 3.114.31 4.694.77 4.785.06 4.674.19 4.153.73 3.593.34 3.274.41 4.26

2.27 2.30 6151.88 2.051.67 1.832.53 2.48 55374067 882 9766

76 363 4723905

59 053569 366386 3739

74560375886 3

In chloroform at 37". The existence of solvents was confirmed by 'H NMR spec tra. It is not obvious whether this complex is cis ortrans.Experimental Section

Materials. p-Methylpyridinium phenacylide (Ny)," methyldi-phenylphosphonium phenacylide (Py),l2 and dimethylsulfoniumphenacylide (Sy)l3 were prepared according to the literature.Triphenylarsonium phenacylide (Ay) was synthesized in the same wayas Py.All manipulations for preparing the ylide complexes were carriedout in air.Preparation of Dihalogenodimethylphenylphosphine(dimethyl-sulfonium phenacylide)platinum(II), PtXz(PPhMez)(Sy) (X = CI, Br,I), and Related Compounds. A 10-ml dichloromethane solution ofSy (0.094 g, 0.52 mmol) was added to a 5-ml dichloromethane solutionof di-~-chloro-dichlorobis(dimethylphenylphosphine)diplatinum(I p(0.20 g, 0.25 mmol), and the mixture was stirred for 3.5 hr. Theaddition of petroleum ether to the solution gave a small amou nt ofwhite crystals of ci~-PtCh(PPhMe2)(Sy),which was separated byfiltra tion and dried in vacuo. The trans isomer was obtained as yellowcrystals (0.18 g, yield 62%) by further additions of petroleum etherto the filtrate. The dibromo and diiodo complexes were synthesizedin the same way. The former was mainly obtained as a trans isomer(yellow), whereas the latter was predominantly a cis one (yellow).The recry stallizations of the trans-d ichloride and -dibromide fromchloroform gave the corresponding cis complex containing one moleculeof chloroform.Othe r platinum(I1) complexes, PtXzLY (X = CI, L = PPhMe2,Y = Ny, Py, Ay; X = Br, I, L = PPhMez, Y = Ny, Py; X = CI, L= PMe3, Y = Ny, Py, Ay, Sy) were prepared i n dichloromethaneor 1,2-dichloroethane in the similar way. PtCh(P Me3)Y (Y = Py,Sy) were purified from a benzene-diethyl ether mixture, and theremaining complexes from dichloromethane or 1,2-dichloroethane-petroleum ether.Preparation of Dichlorodimethylphenylphosphine(dimethylsulfoniumphenacylide)palladium(II), PdC12(PPhMez)(Sy), and RelatedCompounds. A 10-ml dichlorom ethane solution of Sy (0.12 g, 0.67mmol) was dropped into a 5-ml dichloromethane solution of di-r-chloro-dichlorobis(dimethylphenylphosphine)dipalladium(lI)0.20g, 0.32 mmol). The solution changed in color from orange to yellow.After the reaction mixture had been stirred for 1 hr, petroleum etherwas added to the solution to give light yellow crystals (0.17 g, yield

Other palladium(I1) complexes, PdChLY (L = PPhMez,Y = Py,Ay; L = PMe3, Y = Py, Ay, Sy) were isolated in the same way, butonly PdClz(PMe3)(Py) was obtained from benzene-diethyl ether.The melting points and analytical data for the ylide complexesprepared are summarized i n Table I.Physical Measurements. Infrared (4000-200 cm-I), IH N M R

54%).

Table 11. Ir Data of the Ylide Complexes (cm -')v ( M - X )u(C=O) u(M-C) Nujol mullNujol Nujol (dichloro-Complex mull mull methane)

NYtrans-PtC1, (PPhMe,)(Ny)trans-PtBr, PPhMe,)(Ny)trans-PtI, PPhMe,)(Ny)trans-PtC1, (PMe,)(Ny)AYcis-PdC1, (PPhMe,)(Ay)PdCI, (PMe,)(Ay )trans-PtC1, (PPhMe,)(Ay)trans-PtCl,(PMe )(Ay)SYcis-PdC1, PPhMe,)(Sy)cis-PdC1, (PMe,)(Sy)

trans-PtC1, (PPhMe,)(Sy)cis-PtC1, (PPhMe,)(Sy)trans-PtBr, PPhMe,)(Sy)cis-PtBr, PhMe,)(Sy)trans-PtI, PPhMe,)(Sy)cis-PtI, (PPhMe, )(Sy)trans-PtC1, (PMe,)(Sy)PYtrans-PdC1, (PMe,)(Py)trans-PtC1, (PPhMe,)(Py)tmns-PtBr, PPhMe, (Py)trans-PtI,(PPhMe,)(Py)trans-PtC1, (PMe,)(Py)

trQns-PdC1, PPhMe, (Py)

14991645 5251644 5281647 5241643 52715081633 a1627 a1629 a1637 a15081631 5171633 523

1633 5161636 5441632 5131636 5351633 5201627 5191623 51014991607 a1621 5101622 5171632 5171636 5241633 525

Obscured by the ligand bands.observed due to its low solubility.spectra,IO and molecular weights's were measured as describedelsewhere. The complexes are essentially monomeric i n chloroformas shown in Table 1.Results and DiscussionThe carbonyl stretching band of the ylide complexes wasobserved at higher frequencies than those of the original ylidesas found in Table 11. This indicates increasing double-bond

Other bands were not

331 (332)24 3335 (334)aa339 (338)330 (330)296,265(350b)268,245(35 1,270,246)337 (337)312,28024 3

338 (337)345 (346)348 (347)334 (337)245338 (336)


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Ylide-Metal Complex Inorganic Chemistry, Vol. 15, No. 2, 1976 419Table 111. 'H NMR Data of the Yl ide Complexes at 23"

Coupl ing constants, Hza,J-hem shifts, 8 , p pmY lide ZJ(195pt- 3J()'P- (J lp - 3J(IP5pt-

Complex So lven t* CH Yl ideCH, Y l ideo-HC Nya- Hd P C H , CH) M-CH) CH, P-CH,)NYtrans-PtCl ,(PPhMe,)(Ny)t rans-PtBr, (PPhMe,)(Ny)trans-PtI , PPhMe ,)(Ny )trans-PtC1, (PMe,)(Ny)t rans-PdCl ,(PPhMe,)(Ay)t rans-PdCl ,(PMe,)(Ay)trans-PtC1, (PPhMe,)(Ay)

AY

trans-PtC1, (PMe ,)(Ay)SYtrans-PdCI,(PPhMe,)(Sy)cis-PdC1, (PPhMe,)(S y)trans-PdCl,(F'Me,)(Sy)cis-PdC1, (PMe )(S y)trans-PtCl, (PPhMe,)(Sy)cis-PtC1, VPhMe ,)(Sy )trans-PtBr, (PPhMe,)(Sy)cis-Pt Br, PPhMe ,)(Sy)t rans-PtI, (PPhMe,)(Sy)cis-PtI, (PPhMe,)(Sy)trans-PtC1, (PMe,)(Sy)PYtrans-PdC1, (PPhM e,)(Py)t rans-PdCl ,(PMe,)(Py)trans-PtC1, (PPhM e,)(Py)trans-PtBr, (PPhMe,)(Py)t rans-PtI, (PPhMe,)(Py)trans-PtC1, (PMe,)( Py)

AAAAAAAAAAABBBBBABABABAAAAAAAA

6.646.887.137.576.824 .705.715.636.055.974.324 .405.085 .724.955.695.335.985.63f6.22f5 .244.245.145.015.365.716.335.25

2.352.532.522.5 32.56

2.962.813.00,3.12,3.04,3.12,3.02,3.04,3.00,3.07,3.00,2.96,3.05,2.432.822.852.782.802.852.81

2.712.802.692.832.762.772.732.8 12.742.802.77

7.808.448 . 4 38.388.487.978 .438.408.438.407.797.698.278.068.298.298.368.058.388.078.368.018.417.898.388.358.388.398.368.34

9.47 11 23.84 1 .64 , 91 1211 25.90 1 .76 96 13

8.99 2.06 100 11 10 2711 22.86 1 .39 90 12

1.62

1 .67 , 12 111.611 .35 12 1 21 .71 , 8 5 1 0 1 0 2 61.641.39 82 11 11 25

1.59 1 3 1 21.74 Oe 1 21 .32 12 121.39 oe 1 21.69. 85 11 11 24

1.82, 90 11 11 241.801.86 f f 11 372.12 9 4 1 0 1 1 2 82.00 f f 11 391 .44 84 11 11 25

1.65, I: 111.34 I: 1 21.68, 7 9 I: 11 261.82, 8 4 R 10 262.12, 91 I: 11 271.39 7 7 R 11 26

1.621.651.792.09

a Uncertainty + I Hz . * A = chloroform-d, ; B = dimethyl-d, sul foxide. Or tho pro tons o f t he phenyl g roup . 01 p r o t o n s of t h epyridine ring. e Not accu rate because of broad signals. f Obscured by the phenyl signals. g Not determined due to the coupl ings betweenthe yl ide methine proton and two "P nuclei.cha racte r of the carbon-oxygen bond of the ylides upon co-ordination of the ylide carb on to the m etal ions, as previouslymentioned. 10,16 Th e existence of th e ylide carbon-metal bondis also suggested by the observation of the spin-spin couplingbetween the ylide methine proton and the 195Pt nucleus, asshown in Table 111. The formation of the ylide carbon-metalbond leads to a downfield shift of the ortho phenacyl phenylprotons (Table H I ) , which may be due to the increased an-isotropy of the carbonyl grou p.' ' Th e ylide methine signalalso shifted to a lower magnetic field owing to the inductiveeffect of the metal ions upon complexation.It was previously pointed ou t tha t the a protons of thepyridine ring of the free Ny were markedly deshielded fo r theformation of the hydrogen bond with the carbonyl oxygen,giving a six-membered ring.18 This a-pro ton sign al shifts toa higher magnetic field upon complexation. This may be dueto the change of the hyb ridization of the ylide carbon orbitalsfrom sp? to sp3 and the reduction of negative char ges on th e

carbonyl oxygen upon formation of the ylide carbon-metalbond.The Palladiurn(I1)-Ylide Complexes. The PdC12L(Sy)complexes (L = PPhMez, PMe3) exhibited two v(Pd-C1)bands in the solid state (Table II) , which suggests a cisconfiguration around the palladium atom. In dichloromethane,however, an ad ditional band w as observed at 350 or 351 cm-'when L = PPhMez or PMe3, indicating the app earan ce of atrans isomer. Th e coexistence of the cis and trans isomers insolution is also confirmed by the IH N M R s p e c tr a ; t h e Sycomplexes in dimethyl-& sulfoxide displayed two doub lets ofS-CH3 and a singlet and a doublet of methine signals (Table111). Th e higher field pair of S-CH3 signals and th e doubletsignals of methine proton m ay be assigned to the tran s isomer,because (i) the Sy in the trans isomer is subjected to a strongtran s influence of the phosphorus ligand, which ma y result ina weaker palladium-carbon bond than th e cis one and (ii) thespin-spin coupling between the ylide methine proton an d 3iP


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420 Inorganic Chemis try, Vol. 15, No. 2, 1976nucleus is expected to occur in the trans isomer rather thanin the cis isomer (Ta ble 111). Integr ated intensity of theS-CH3 signals revealed tha t th e ratio of the cis to tran s isomerwas about 2.8:l and 4.5: l for the PPhMez and PMe3 com-plexes , respectively. Th e fact that PdC lz(PMe j)(Sy) has alarger portion of the cis isomer would be mainly attributedt o a smaller steric repulsion between S y and PMe3.T h e 1HN M R spectra of PdClzL(Ay) (L = PPhMez, PMe3)in chloroform-di indicated the existence of only one isomer,and the 3J(P-Pd-CH) values were both 12 ( f l ) H z . T h i svalue is almost identical with those of trans-PdClzL(Sy),suggesting a trans a rrang emen t of th e complexes in solution,although the configuration in the solid state has not beendeterm ined because the v(Pd-C1) is obscured by the ab-sorptio ns of Ay. In the synthetic process of PdC12-(PPh Mez )(A y), the addition of a large amoun t of petroleumether to a solut ion containing di-pchloro-dichlorobis(di-methylphenylphosphine)dipalladium(II) and Ay gave amixtu re of a yellow powder and orang e crystals. The y ex-hibited the u(C=O) band a t 163 3 and 1621 cm--I in the solidstate, respectively. Th e forme r frequency, however, moveddown to 1623 cm-1 in dichloromethane. In addition, the IHN M R spectra of both products in chloroform-di were qui tesimilar to tha t of the tra ns isomer described above. In viewof these results, the yellow compound would be a cis isomerwhich easily isomerizes to a trans isomer in solution, and th eorange crys tals would be a t rans isomer,

PdClzL(Py) (L = PPhMez, PMe3) exhibi ted only oneu(Pd-Cl) band b oth in the solid state and in solution, sug-gesting a trans configuration around the palladium atom.The Platinum(I1)-Ylide Complexes. Th e solid-state spectraof PtXzLY (X = C1, L = PPhMez , Y = Ny, Ay, Py; X = C1,L = PMe3, Y = Ny, Ay, Sy , Py; X = Br, L = PPhMez, Y= Ny , Py) show only one v(Pt-X) band around 335 cm-1 forthe dichlorides, or 24 5 cm-1 for the dibromides, indicating atran s configuration around the platinum. Th e 3J(P-Pt-CH)values (1 1 f Hz) of these complexes suggest a trans structurein solution. Th e diiodide complexes PtIz(P PhM e2)Y ( Y = N y ,Py) in solution are also assigned to a trans arrangement onth e basis of the 3J(P-Pt-CH) an d 3J(Pt-P-CH3) values, whichar e almost identical with those of the corresponding dichlorideand dibromide complexes (Table 111). In view of the fact tha tthe configurations of th e dichlorides and dibromides in solutionare identical with those in the solid state, respectively, thediiodide complexes may be assumed to have a trans config-uration in the solid state, too.

Two isomers of PtXz(PPhM ez)(Sy) ( X = C1, Br, I) weresepara tely isolated; the m ajor prod uct is a trans isomer andthe minor one a cis isomer when X = C1 or B r, as revealedfrom infrared spectra. Th e diicdo complex was predominantlya cis form. The cis -dichloride and -dibromide and thetrans-diiodide are sta ble to isomerization in solution. On theother han d, th e trans-dichloro complex quickly underwent anisomerization to a cis form an d the trans-dibromide slowly didso when dissolved in chlorof orm. Th e cis-diiodide par tlyisomerized in dimethyl-& sulfoxide, as detected by m eans of1H N M R spectra . These observations may be related to thefact that the v(Pt-C) of the dichloride and dibromide com-plexes is lower in the trans isomers than in the cis isomers,while both isomers of the diiodide complexes, whose meltingpoints are very close, display nearly the sam e u(Pt-C) fre-quencies (Ta ble 11 ) .

T he average frequency (296 cm-1) of two u(Pt-C1) ban dsof cis -PtCh(P PhMe z)(Sy) is lower than th at (304 cm--l) ofcis-PtCIz(PPhMez)2,19 indicating a la rger trans influence ofSy than of PPhMez .Th e pKa values of the conjugated acids of Ny, Ay, Sy, andPy were reported to be 10.5, 8.25, 7.68, and 6.51, respec-

Koezuka, Matsubayashi , and Tanakatively.18JO Th e ZJ(Pt-CH ) value of the platinum-ylidecomplexes with the sam e configuration approxim ately increasesin this order of the pKa value (see Table 111). It should benoted that the zJ(Pt-CH) values obtained in the present tran scomplexes (77-100 Hz), though they are smaller than theZJ(Pt-CH) value of trans-PtClz(CH3CHzC-HN+C5Hs)-(CsH5N) (115 Hz),21 a re somewhat larger than the V(Pt -C H 3 ) of c i s -P tMez(PPhMez)z (67 Hz)22 and [P tMe-(PPhMe2)3]+ (57 Hz),23 which have the same phosphorusl igand in the t rans posit ion as t rans-PtXz(PPhMe2 )Y ( X =C1, Br, I; Y = Ny, S y, Py). Thus , the yl ide complexes mayinvolve a larger s character in the platinum-carbon bond thanthe methylplatinum compounds. This is also shown from theassumption th at a positively ch arged , electronegative het-eroatom causes an increase in the s character in the Pt-C bondas a result of the rehybridization of the ylide carbon.24Influence of Ligands Cis or Trans to tbe Ylides. A sub-stitution of PMe 3 for the PPhMe:! tran s to an ylide caused areduct ion in the zJ(Pt-CH). This is explained by theweakening of the ylide carbon--metal bond in the PMe3complexes, which resulted from th e larger t ran s influence ofPMe3 (pKa = 8.65) than of PPhMez (pKa = 6.50).25Th e v(Pt-C) frequency of cis-PtXz(P PhMe z)(Sy) (X = C1,Br , I) decreases on going from Cl to I. This result is consistentwith the ord er of the trans influence of the halide ions. Onthe other hand, t rans-PtXz(PPhMe2)Y (X = C1, Br, I; Y =Ny, Sy , Py) howed an opposite trend; the u(Pt-C) frequencyof the diiodide complex is equal to or higher th an tha t of th ecorresponding dichloride. In addition, the zJ(Pt-CH) valueincreases in th e order of C1C Br C I. These are not explainedin terms of the cis labile property of halide ions, Le., I > Br> C1, estimated from th e spi ns pi n coupling constant betweenthe 31P and 195Pt nuclei in a variety of platinum(I1) com-plexes.2Q7 In view of a significant role of the onium centerto stabilize ylide-metal complexes, as mentioned in the in-troductory section, the phenomena conflicting with the cisinfluence of halide ions may be interpreted as follows; theelectronic polarizability of the halogens augments on passingfrom CI to I, and therefore the electronic interaction (A ) of

\c___ 26 I+-..

rl.(Z = a heteroatom group)the halide ion with a heteroatom involving positive chargesincreases in the same order. This interaction polarizes theplatinum-halogen bond to decrease the s character, resultingin enrichment of the electron density in the 6s valence orbitalat the platinum a tom. A similar electronic polarization mayoccur in the ylide carbon-heteroatom bond. These interactionsrecall an intermediate of the Wittig reaction. Th e synergeticpolarization of this kind would cause a high-frequency shiftof the v(Pt-C) and an increase of the V(P t-CH ) value in thediiodo complexes (see Tables I1 and 111). An increase of th e3J(Pt-P-CH3) value is also seen on going from CI to I . It istherefore suggested that the increment of 2J(Pt--CH) andv (Pt -C) is mainly d ue to the p olarization of the m etal-halogenbond, because that of the ylide carbon-heteroatom bond wouldstreng then the platinum-ylide carbo n bond to weaken theplatinum-phosphoru s bond , resulting in a decrease of th e3J(Pt-P-CH3) value.

Registry N o. trans-PtC12(PPhMez)(Ny), 57396-07-3; trcins-Pt Br2( PPh Me2) (Ny ) , 57 396-08-4 ; t r a m -Pt I?(P P h M e2) ( N y ),57396-09-5 ; t rans-P tC lz(PMe3)(Yy) , 57396-10-8 ; t runs-PdClz-(PPhMez) (Ay) , 57396-1 1 -9 ; c i s -PdCI?(PP hMe2)( ,2y ) , 7456-87-8 ;


5/5

Magnet ic Propert ies of [Cu(DMAEP)OH]z(C104)2trans-PdCIz(PMe3)(Ay), 57396-12-0;rans-PtCh(PPhMe2)(Ay),57396- 3- ; rrans-PtCIz(PMe3)(Ay), 57396-1 -2; rans-PdCIz-(PPhMez)(Sy),57396-1 -3; i+PdCh(PPhMe2)(Sy), 57456-88-9;trans-PdCIz(PMe3)(Sy), 57396-16-4; is-PdCh(PMe3)(Sy),57456-89-0;rans-PtClz(PPhMez)(Sy), 57396-17-5; is-PtClz-(PPhMez)(Sy), 57456-90-3;ran~-PtBrz(PPhMe2)(Sy),7396-18-6;cis-PtBrz(PPhMez)(Sy), 57456-91-4; rans-PtIz(PPhMez)(Sy),57396-19-7; is-PtIz(PPhMez)(Sy), 57456-92-5; rans-PtCIz-(PMe,)(Sy), 57396-20-0;rans-PdClz(PPhMez)(Py), 57396-21-1;trans-PdCh(PMe3)(Py), 57396-22-2;rans-PtCh(PPhMez)(Py),57396-23-3;rans-PtBr2(PPhMe2)(Py), 57396-24-4;rans-PtIz-(PPhMez)(Py), 57396-25-5;rans-PtClz(PMe3)(Py),57396-26-6; y,25357-50-0; y, 24904-06-1; y, 5633-34-1;y (charged form),57395-87-6; i-p-chloro-dichlorobis(dimethylphenylphosphine)di-platinum(II), 15699-79-3;i-p-chloro-dichlorobis(dimethylpheny1-phosphine)dipalladium(II), 15699-80-6; y (uncharged form),References and Notes57395-88-7.

( I ) M. Keeton, R. Mason, and D. R. Russell, J. Organomet. Chem., 33,259(I97 1).(2 ) F. Heydenreich, A. Mollbach,G.Wllke, H. Dreeskamp, E. G. Hoffmann,G. Schroth, K. Seevogel, and W . Stempfle, Isr. J. Chem., 10,293 (1972).(3) P. Bravo,G. Fronza, C. Ticozzi, and G. Gaudiano, J . Organomet. Chem.,74, 143 (1974).(4) H. Schmidb aur, J. Adlkofer, and W. Buchner, Angew. Chem., 85,448(1973); H. Schmidbaur , J. Adlkofer, and M. Heimann, Chem. Ber., 107,3697 (1974).(5) H. Schmidbaur and R. Franke, Angew. Chem., 85,449 (1973)

Inorganic Chemis try, Vol. 15 , No. 2, 1976 421(6 ) H. H. Karsch and H. Schmidbaur, Angew. Chem., 85,9 10 (1973); H.H. Karsch and H Schmidba ur, Chem. Ber., 107, 3684 (1974).(7) H. H. Karsch, H.-F. Klein, and H. Sch midbaur, Chem. Ber., 107, 93(1974).(8 ) H. Schmidbaur and H.-J. Fuller, Chem. Ber., 107, 3674 (1974).(9) H. Schmidbaur, Acc. Chem. Res. , 8, 62 (1975).(IO) H. Koezuka, G. Matsubayashi, and T. Tanaka, Inorg. Chem., 13,443( 1974)(11) F. Krohnke, Chem. Ber., 68 , 1177 (1935).(12) F. Ramirez and S. Dershowitz, J. Org. Chem., 22, 41 (1957).(13) K. W. Ratts and A. N. Yao, J. Org. Chem., 31, 1185 (1966).(14) F. R. Hartley and G. W. Searle, Inorg. Chem., 12, 1949 (1973).(15) H. Koezuka, G. Matsubayashi, and T. Tanak a, Inorg. Chem., 14 ,253(1975).( 1 6) Y. Omawa, T. Miyamoto, T. Saito, and Y. Sasaki, Chem.Letr., 33 (1975).(17) L. M. Jackman, and S. Sternhell, Applications of Nuclear MagneticResonance Spectroscopy in Org anic Chemistry, 2nd ed, ergamon Press,_Oxford, 1969, p 88.(18) W. G. Phillips and K . W. Ratts, J . Org. Chem., 35 , 3144 (1970).(19) D. G. Coooer and J. Powell. J . A m . Chem. SOC . , 5, 1102 (1973).(20) A. W. Johison and R. T. Amel, Can. J. Chem., 46, 461 (1968).(21) R. D. Gillard, M. Keeton, R. Mason, M. F. Pilbrow, and D. R. Russell,

J. Organonret. Chem., 33, 247 (1971).(22) J. D. Ruddick and B. L . Shaw, J . Chem. SOC. , 2801 (1969).(23) H. C. Clark and J. D. Ruddick, Inorg. Chem., 9,1226 (1970).(24) H. A. Bent, Chem. Reo., 61, 275 (1961).(25) C . A. Streuli. Anal. Chem., 32, 985 (1960).(26) T. G. Appleton, H. C. Clark, and L. E. Manzer, Coord. Chem. Reti.,10, 335 (1973).(27) A. Pidcock, R. E. Richards, and L M. Venanzi, J . Chem. SOC. , 1707(1966): G. Socrates, J. Inorg. Nucl. Chem.,31, 1667 (1969); F. H. Allen,A. Pidcock, and C . R. Waterhouse, J . Chem. SOC.A , 2087 (1970): F.H. Allen and S. N. Sze, ibid., 2054 (1971).

Contribution from the Department of Chemistry,The University of North Carolina, Chapel Hill, North Carolina 27514Magnetic Properties ofar-Di-~-hydroxo-bis[2-(2-dimethylaminoethyl)pyridinecopper(II)] Perchlorate,a- [Cu(DMAEP)OH]2 ( C l O 4 ) 2KENNETH T. McGREGOR, DEREK J . HODGSON, and WILLIAM E. HATFIELDReceived June 13, 1975 AIC504178

The magnetic susceptibility and electron paramagnetic resonance spectra of a-di-p-hydroxo-bis[2-(2-dimethylamino-ethyl)pyridinecopper(II)] perchlorate are reported. The susceptibilitydata are characteristic of exchange-coupledcopper(I1)pairs with a small interpair interaction. The pairwise interaction results in a singlet ground state for the pair with a verylow-lying triplet excited state. A crossover of the triplet and singlet energy levels is produced with an applied field of -50kG . The magnetic parameters derived are J = -2.35 l: 0.2 m-1, J -0.1 cm-1, g = 2.08f 0.02, nd D = 0.4 m-1.The results are discussed in terms of the molecular structure of the complex and compared to structurally similar systems.

Th e preparat ion and characterizat ion of a number of di-hydroxo-bridged copper(I1) complexes which belong to thegenera l class [ C U ( L ) O H ] ~ X ~ - ~ H ~ Oave been reported.1-4Here L has been a variety of chelating amines and X- has beenseveral counterions such as C104-, Br-, 1/ 2 SO&, etc . Themagnet ic propert ies of this series are characteristic ofexchange-c oupled copper(I1) ions. For these systems, thesinglet-triplet (S-T) splitting energy , which results from theisotropic exchange interaction, ranges from large positivevalues (triplet ground states) to very large negative values(singlet ground states). Studie s on this series have yieldedmuch useful information in our continuing efforts to correlatethe structural and magnetic properties of magnetically con-densed systems. Th e structural properties vary only slightlythroughout the series while the magnetic properties varygreatly. Ou r investigation of several memb ers of the serieshas revealedz-4 a striking correlation between the S-T splitting2 J and the Cu-0-Cu br idge angle 4.Recently, Uhlig an d co-workers reported5 the preparationof complexes formed with copper(I1) and N-substituted 2-(2-aminoethy1)py ridine which, on the basis of th e spectral andhigh-temperature magnetic da ta, should belong to this series.

Of particular interest is the reaction of copper(I1) perchlorateand 2-(2-dimethylaminoethyl)pyridine D M A E P ) . R e c e n tstruc tural investigations3.6 have revealed th e existence of twoforms of complex. Th e monoclinic form does belong to thestructural class and obeys the near-linear 2 5 vs. 4 relationship.Th e triclinic a form, however, does not belong to this structuralclass since the copper(I1) ions are bridged by the perchloratoanions as well as the hydroxo groups.We report here the m agnet ic propert ies of the a form ofthe D M AE P complex which indicate tha t the exchange in-teraction is greatly affected by this structural change. Themagnetic p roperties of CY -DMA EP re of special interest sincea n S-T crossover is produced by large applied magneticfields, a phenomenon which has received very little attentionin previous reports of exch ange-coup led systems.

Experimental SectionPreparation. The addition of 2-(2-dimethylaminoethyl)pyridineto an equimolar quantity of copper(1l) perchlorate hexahydrate i na minimum volume of an alcohol-ether solution yields a blue pre-cipitate having the stoichiometry Cu(DMAEP)OHC104. Magneticmeasurements (vide supra) indicate that this precipitate is a mixtureof the a nd 13 forms of the complex. Cry stal growth from an absolute

ylide-metal complex to dryness and the residue was extracted with

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