NEUTRAL AND CATIONIC RUTHENIUM HYDROTRIS(PYRAZOLYL)BORATE DERIVATIVESCONTAINING BULKY MONODENTATE PHOSPHINES - CRYSTAL-STRUCTURES OF UTP(H2O)((PPR2ME)-ME-I)(2)][CF3SO3]CENTER-DOT-ETOH AND [RUTP(N-2)(PET3)(2)][BPH4]

The complexes [RuTp(Cl)((PPr2Me)-Me-i)(2)] 1 and [RuTp(Cl)(PEt3)(2)] 2 were prepared by thermal displacement of PPh3 from [RuTp(Cl)(PPh3)(2) ] by the corresponding phosphine. A series of cationic complexes of th e type [RuTp(L)(PR3)(2)](+) (L = H2O, N-2 Or CNBut; PR3 = (PPr2Me)-Me- i or PEt3) was obtained by chloride abstraction from 1 or 2 in the pre sence of L. As consequence of the steric crowding, one of the (PPr2Me) -Me-i ligands in I is labile, and it was readily replaced by neutral m olecules such as MeCN or CNBut to yield the neutral complexes [RuTp(Cl )L((PPr2Me)-Me-i)] (L = MeCN or CNBut). The monohydrides [RuTp(H)((PPr 2Me)-Me-i)(2)] and [RuTp(H)(PEt3)(2)] were obtained by treatment of 1 or 2 with NaBH4 in MeOH. Protonation of these monohydrides led to the cationic dihydrogen complexes [RuTp(H-2)((PPr2Me)-Me-i)(2)](+) and [Ru Tp(H-2)(PEt3)(2)](+) which were isolated as [BPh4](-) salts, and chara cterized by determination of their (T-1)(min) and (1)J(HD) coupling co nstants in the corresponding isotopomers. The neutral hydride(dihydrog en) complex [RuTp(H)(H-2)((PPr2Me)-Me-i)], which resulted from the rea ction of [RuTp(Cl)(MeCN)((PPr2Me)-Me-i)] with NaBH4 in MeOH, was chara cterized in analogous fashion. The crystal structures of the complexes [RuTp(H2O)((PPt2Me)-Me-i)(2)][CF3SO3]. EtOH and [RuTp(N-2)(PEt3)(2)][ BPh4] were determined.