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-methyl-2-thioxo-1-imidazolyl)borates

(Trialkyl- and (triarylphosphine)silver(I) derivatives containing anionic tris(1 H- pyrazol-1-yl)borates were prepared from AgX (X = CF 3 SO 3 or NO 3 ), PR 3 (R = phenyl, benzyl, cyclohexyl, 2,4,6-trimethylphenyl, or o -, m -, and p -tolyl) or PMePh 2, and M[HB(pz) 3 ] [M = K or Na; pzH = pyrazole in general; in detail, pyrazole (PzH), 3,5-dimethylpyrazole (3,5-Me 2 PzH), or 4-bromopyrazole (4-BrPzH)] and characterized through analytical and spectral (IR; 1 H, 13 C, and 31 P NMR) measurements. These air stable, light-sensitive complexes are not electrolytes in CH 2 Cl 2 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 = 0.710 70 Å) at 293 K: [HB(Pz) 3 ]Ag(PPh 3 ), C 54 H 50 Ag 2 B 2 N 12 P 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, P 1̄, Z = 2; [HB(Pz) 3 ]Ag[P( o- tolyl) 3 ], C 30 H 31 AgBN 6 P, a = 14.461(2) Å, b = 14.461(2) Å, c = 30.473(2) Å, α = 90°, β = 90°, γ = 120°, trigonal, R 3̄, Z = 6; [HB(Pz) 3 ]AgP(Bz) 3, C 30 H 31 AgBN 6 P, a = 12.183(2) Å, b = 18.596(2) Å, c = 13.804(2) Å, β = 100.8(1)°, monoclinic, P 2 1 / n, Z = 4; [HB(3,5-Me 2 Pz) 3 ]Ag[P( p- tolyl) 3 ], C 36 H 41 AgBN 6 P, a = 34.839(3) Å, b = 10.375(2) Å, c = 10.203(2) Å, β = 90.8(1)°, monoclinic, P 2 1 /n, Z = 4. Crystal data with Cu Kα (λ = 1.5418 Å): [HB(4-BrPz) 3 ]AgPPh 3, C 27 H 22 AgBBr 3 N 6 P 2, 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, P 1̄, Z = 2. The anionic soft S 3 -donor hydrotris(3-methyl-2-thioxo-1-imidazolyl)borate (Tm) was synthesized as its potassium salt from the corresponding imidazole and KBH 4 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(PPh 3 ). The S - donor 1-methylimidazolyl-2-thione (Hmimt) reacts with [HB(3,5-Me 2 Pz) 3 ]Ag(PPh 3 ), yielding the derivative [HB(3,5-Me 2 Pz) 3 ](Hmimt)AgPPh 3 in which the [HB(3,5-Me 2 Pz) 3 ] - acts likely as bidentate N 2 -donor.