Syntheses and Spectroscopic and Structural Characterization of Silver(I) Complexes Containing Tertiary Phosphines and Hydrotris(pyrazol-1-yl)-, Hydrotris(4-bromopyrazol-1-yl)-, Hydrotris(3,5-dimethypyrazol-1-yl)-, and Hydrotris(3-methy1-2-thioxo-1-imidazoly)borates

(Trialkyl- and (triarylphosphine)silver (I) derivatives containing anionic tris(1H-pyrazol-l-yl)borates were prepared from AgX (X = CF3SO3 or NO3), PR3 (R = phenyl, benzyl, cyclohexyl, 2,4,6-trimethylphenyl, or o-, m-, and p-tolyl) or PMePh2, and M[HB(pz)3] [M = K or Na; pzH = pyrazole in general; in detail, pyrazole (PzH), 3,5-dimethylpyrazole (3,5-Me2PzH), or 4-bromopyrazole (4-BrPzH)] and characterized through analytical and spectral (IR; 1H, 13C, and 31P NMR) measurements. These air stable, light-sensitive complexes are not electrolytes in CH2Cl2 and acetone. In these solvents they decompose even with strict exclusion of oxygen and light. The solid-state structures show that the silver atom adopts a distorted tetrahedral geometry. Crystal data with Mo Kα (λ = 0.71070 Å) at 293 K: [HB(Pz)3]Ag(PPh3), C54H50Ag2B2N12P 2, a = 15.082(2) Å, b = 19.728(2) Å, c = 9.432(1) Å, α = 94.8(1)°, β = 107.4(1)°, γ = 87.8(1)°, triclinic, P1̄, Z = 2; [HB(Pz)3]Ag[P(o-tolyl)3], C30H31-AgBN6P, a = 14.461(2) Å, b = 14.461(2) Å, c = 30.473(2) Å, α = 90°, β = 90°, γ = 120°, trigonal, R3̄, Z = 6; [HB(Pz)3]AgP(Bz)3, C30H31AgBN6P, a = 12.183(2) Å, b = 18.596(2) Å, c = 13.804(2) Å, β = 100.8(1)°, monoclinic, P21/n, Z = 4; [HB(3,5-Me2Pz)3]Ag[P(p-tolyl)3], C36H41AgBN6P, a = 34.839(3) Å, b = 10.375(2) Å, c = 10.203(2) Å, β = 90.8(1)°, monoclinic, P21/n, Z = 4. Crystal data with Cu Kα (λ = 1.5418 Å): [HB(4-BrPz)3]AgPPh3, C27H22AgBBr3N6P2, a = 10.306(2) Å, b = 11.425(2) Å, c = 13.571(2) Å, α = 90.3(1)°, β= 107.0(1)°, γ = 91.4(1)°, triclinic, P1̄, Z = 2. The anionic soft S3-donor hydrotris(3-methyl-2-thioxo-l-imidazolyl)borate (Tm) was synthesized as its potassium salt from the corresponding imidazole and KBH4 in high yield. The potassium complex KTm was used as ligand transfer agent in the preparation of the silver (I) derivatives [(Tm)Ag]n and (Tm)Ag(PPh3). The S-donor 1-methylimidazolyl-2-thione (Hmimt) reacts with [HB(3,5-Me2-Pz)3]Ag(PPh3), yielding the derivative [HB(3,5-Me2Pz)3](Hmimt)AgPPh3 in which the [HB(3,5-Me2Pz)3]- acts likely as bidentate N2-donor.