BRIE F C OMMUNICATIONS

C O M P L E X E S OF DECABORANE W I T H O R G A N I C P H O S P H O R U S

AND ARSENIC COMPOUNDS

L. I. Z a k h a r k i n a n d V. I. S t a n k o

Institute for Heteroorganic Compounds, Academy of Sciences of the USSR Translated from Izvestiya Akademii Nauk SSSR, Otdelenie Khimicheskikh Nauk, No. 11, pp. 2078-2079, November, 1961 Original article submitted May 30, 1961

According to the literature, decaborane is able to form complexes with various electron-donating compounds, for example, with tertiary amines, triphenylphosphine, acetonitrile, diethylcyanamide, etc. [1-3]. The reaction oc- curs according to the following equations:

BtoH14+2CHaCN . . . . Bt0Ht2 [CHaCN] ~q-H2 BloHt4+2P (Calls)a- ~ BxoHrz [(C~H.~)sP]2+H,

B10H14+2 (C2Hs),NCN -" BloHl~ [(C~H~)~NCNJ,+H~~

2-Isopropyl- and 2-methyl-5-(2-chloroethyl)tetrazoles react with decaborane similarly [4]:

BIoH14+2C4N4H8 -o BloHt2 (CjN4Hs),2+H2 ~

In the present work, we studied the reaction of decaborane with trialkyl- and triaryl-derivatives of group five elements: P, As, and Sb. The reaction of triethylphosphine with decaborane occurred energetically with evolution of heat, vigorous hydrogen evolution, and complex formation according to the scheme:

BloH14+2 (C2Hs)aP - CloHl= [(C,Hs)jPh+H2.

The reaction with triethylarsine occurred similarly, but the reaction took place only on heating (60-80~

Bt0Hl4+2 (C2Hs)aAs --, BxoH12 I(C, Hs)aAs]2+H=.

On heating triethylstibene with decaborane at 150 ~ the corresponding complex could not be isolated although gas evolution was observed. It was shown that by heating diphenylchlorophosphine with decaborane in benzene, a complex was formed as in the case of triphenylphosphine:

2(C6H~),zPCI + BIoH14 ~ B10Hlz[(C6Hs)zPC1]z + H2.

Phenyldichlorophosphine does not form a complex with decaborane either in boiling benzene or in toluene. Tri- phenylarsine forms a complex with decaborane with evolution of the theoretical amount of hydrogen only at 110" (in toluene). However, the complex partially decomposes upon prolonged heating:

BxoHl4 + (C~H~)aAs "-" Bx0Hla[(C0Hr,)sAsh + Ha.

Triphenylstibene and triphenylbismuthine do not react with decaborane upon boiling in toluene. It was esta- blished that triethylphosphine, diphenylchlorophosphine, and triethylarsine take part in an exchange reaction with diacetonitriledecaborane, as a result of which the corresponding complexes are isolated in the latter two cases*.

BI,,Hz~(CHaCN)~ + 2As(C2Hs)a ~ BloHr, I(C~Hs)aAs]2 + 2CHaCNj BloH12(CHaCN)., "4- 2(CeHs).,PCI ~ BloH12{(C6Hs)2PCI]o. q-2CHaCN.

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E X P E R I M E N T A L

Reaction of Triethylphosphine with Decaborane. To a solution of 0.6 g (0.005 M) of decaborane in 20 ml of ether or benzene in a nitrogen atmosphere was added an ethereal or benzene solution of 1.4 g (0.015 M) of triethyl- phosphine. An exothermic reaction and vigorous hydrogen evolution took place upon mixing. The reaction mixture was heated on a water bath until hydrogen evolution stopped (120 ml of hydrogen was collected). The solvent was distilled under vacuum and the residue was washed with ether to remove excess triethylphosphine. Bis-(triethyl- phosphine)-decaborane melted at 110 ~ after three recrystallizations from methylene chloride. Found: C 40.29, 40.44~ H 11.84, 11.92%. CtzH~Bx0Pz. Calculated: C 40.45; H 11.79%.

Reaction of Triethylarsine with Decaborane, Corresponding to the previous experiment, bis-(triethylarsine)- decaborane was obtained from 0.6 g (0.005 M) of decaborane and 2.0 g (0.012 M) of triethylarsine by heating in benzene. The theoretical amount of hydrogen (120 ml) was evolved. After three recrystallizations from a methyl- ene ch lor ide- ether mixture, bis-(triethylarsine)decaborane melted at 140-141". Found: C 32.42, 32.39; H 9.37, 9.48~ CI2t-I~B10As~. Calculated: C 32.15; H 9.37070.

Reaction of Diphenylchlorophosphine with Decaborane. A s described above, bis-(diphenylchlorophosphine)- decaborane was obtained from 0.6 g (0.005 M) of decaborane and 2.3 g (0.011 M) of diphenylchlorophosphine by heating in benzene. The theoretical amount of hydrogen was evolved. After 8-10 hr standing the substance crystal- lized from benzene. Bis-(diphenylchlorophosphine)decaborane melted with decomposition at 194-196 ~ after recrys- tallization from a methylene chloride - ether mixture and then from methylene chloride. Found: CI 12.65, 12.3707o. C~4H32BIoPz. Calculated: CI 12.6807o.

R__eaction of Triphenylarsine with Decaborane. Decaborane (0.6 g; 0.005 M) in 25 ml of toluene and 3.3 g (0.011 M) of triphenylarsine were heated until the toluene boiled. Hydrogen (120 ml) was evolved. After distilling the toluene the residue was washed several times with ether and recrystallized from methylene chloride. After two recrystallizations from methylene chloride, bis-(triphenylarsine)decaborane melted with decomposition at 152-153". Found: B 13.96%. C~H12B10As,2. Calculated: B 14.75%.

Reaction of Diacetonitriledecaborane with Triethylarsine. Diacetonitriledecaborane (1.0 g, 0.005 M) in 20 ml of benzene was heated with 2,0 g (0.012 M) of triethylarsine for 6 hr on a boiling water bath. After distilling the benzene and washing with ether, the substance was recrystallized from a methylene chloride - ether mixture. The bis-(triethylarsine)decaborane obtained melted at 140". Found: C 32.33, 32,36; H 9.60, 9.41~ CnI-IazBl0Asz. Calculated: C 32.15; H 9.37~

Reaction of Diacetonitriledecaborane with Diphenylchlorophosphine. A s in the above experiment, bis-(di- phenylchlorophosphine)decaborane was obtained from 1.0 g (0.005 M) of diacetonitriledecaborane and 2.3 g (0.011 M) of diphenylchlorophosphine in 20 ml of benzene. After two recrystallizations from a methylene chloride - ether mix- ture, the substance melted with decomposition at 195-197". Found: C1 13.37, 13.3407o. CzaH~B10ClzP2. Calculated: Ct 12.6807o.

SUMMARY

1. Decaborane forms complexes of the following type: B10HIz(ER3) 2 with triethylphosphine, triethylarsine, dE- phenylchlorophosphine, and triphenylarsine.

2. Triethylarsine and diphenylchlorophosphine undergo an exchange reaction with diacetonitritedecaborane with formation of BloHlz[(CzHs)3As] 2 and BIoHtz[(CoHs)zPC1]z.

L I T E R A T U R E C I T E D

1. R. Schaeffer, J. Am. Chem. S.c. "/9, 1006 (1957), 2. M.F. Hawthorne and A. R. Pitochelli, J. Am. Chem. Soc. 80, 6685 (1958). 3. M.F. Hawthorne and A. R. Pitochelli, L Am. Chem. Soc. 81, 5519 (1959). 4. N.R. Fetter, Chem. and Chem. Ind. 1959, 1548.

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