Synthesis and reactions of alkali metal derivatives of the Ph4P2N4S22- dianion: x-ray structure of Cp*Rh(.eta.3-Ph4P2N4S2-N,S,S')

Chivers, Tristram
Edwards, Mark
Gao, Xiaoliang
Hilts, Robert
Parvez, Masood
Vollmerhaus, Rainer
Faculty Advisor
heterocyclic thiazenes , molecular structures , NMR characterization , P2N4S2 ring
Abstract (summary)
The reaction of 1,5-PhP2N& with 2 molar equiv of M[BEt3H] in THF produces {M2[Ph4P2N4S2]}fl (4a, M = Li; 4b, M = Na; 4c, M = K) in quantitative yields with the concomitant evolution of H2 gas. The lithium and sodium derivatives are obtained as insoluble, yellow powders, whereas (K2[Ph4P2N4&]},, (6(31P) = 33.5 ppm) is soluble in THF when formed initially. The reaction of (Na2[Ph4P2N4&]}, with CH212 in THF yields Ph4P2N4S2- CH2 (Sa) in excellent yields. The methylene-bridged compound Sa is readily deprotonated by LiN(SiMe3)z in THF, and the subsequent addition of Me1 produces Ph4P2N4S2CHMe (a).In a similar way, Sb can be deprotonated and methylated to give Ph4P2N4S2CMe2. The reaction of {N~Z[P~P~N~S~]),, with (Cp*RhC12)2 in THF affords Cp*Rh(Ph&N4S2) (6), which can also be produced by the oxidative addition of 1,5-Ph&N& to Cp*Rh(C2H&. The X-ray structure of 6 reveals that the heterocyclic P2N& ligand is bonded to Rh in a tridentate (v3-N,S,S') fashion with d(Rh-N) = 2.135(5) A. Crystals of 6 are triclinic, space group Pi with a = 10.167(1) A, b = 17.972(2) A, c = 9.377(1) A, a= 100.24(1)", /? = 93.19(1)", y = 95.35(1)", V= 1674.2(3) A3, and Z= 2. The final R and R, values were 0.045 and 0.058, respectively. The treatment of {M~[P~I&N&])~ with a variety of other electrophiles, e.g. ICH2CH21, PhCHBr2, CHI3, CBr4, Me2SiCl2, Me2SnCl2, PhPCl2, S2C12, GeC4, or FeBr2, regenerates the folded ring system 1,5-PhP2N&.
Publication Information
Chivers, T., Edwards, M., Gao, X., Hilts, R., Parvez, M. and Vollmerhaus, R. (1995). Synthesis and Reactions of Alkali-Metal Derivatives of the Ph(4)P(2)N(4)S(2)(2-) Dianion - X-Ray Structure of Cp-Asterisk-Rh(Eta(3)-Ph(4)P(2)N(4)S(2)-N,S,S’). Inorganic Chemistry, 34(20), 5037–5041.
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