Silver(I) and gold(I) complexes of hydrotris(3,5-dimethylpyrazol-1-yl)borate: synthesis, spectroscopic and structural characterization, and reactivity toward C-, N- and S-donor ligands

Reaction of Ag(NO3) with 1 equiv of K[HB(3,5-Me(2)pz)(3)] (pzH=pyrazole) and 1 equiv of PR3 (R=OPh or C6F5) in methanol provides two new air stable derivatives {[HB(3,5-Me(2)pz)(3)]Ag(PR3)}. When the interaction between Ag(O3SCF3), CNR (R=Bu-t or cyclohexyl), and K[HB(3,5-Me(2)pz)(3)] was carried out in CH2Cl2 at 0 degrees C the air stable neutral compounds {[HB(3,5-Me(2)pz)(3)]Ag(CNR)} were obtained. The borderline monodentate imidazole (ImH) reacts with the dinuclear {[HB(3,5-Me(2)pz)(3)]Ag}(2) yielding the mixed-ligand complex {[HB(3,5-Me(2)pz)(3)]Ag(ImH)}. On the other hand when the soft donor 1-methyl-2-mercaptoimidazole (Hmimt) was employed, no stable compound was obtained. We also synthesized [Phen(2)Ag](O3SCF3) (Phen= 1,10-phenanthroline) and its reaction with K[HB(3,5-Me(2)pz)(3)] yielded the complex {Phen[HB(3,5-Me(2)pz)(3)]Ag}, which is not fluxional in solution: Instead only unmanageable material was obtained from the reaction between (Hmimt)(2)Ag(O3SCF3) and K[HB(3,5-Me(2)pz)(3)]. Finally, the gold(I) complex [HB(3,5-Me(2)pz)(3)]Au(PPh3)(2) was obtained when the reaction between PPh3AuCl and [HB(3,5-Me(2)pz)(3)] was carried out in presence of 1 equiv of PPh3. The solid state structures of {[HB(3,5-Me(2)pz)(3)]Ag(PPh2Me)} and {[HB(3,5-Me(2)pz)(3)]Ag(P-o-tolyl(3))}, show that the silver(I) atoms are in a strongly distorted tetrahedral environment, with the [HB(3,5-Me(2)pz)(3)](-) donor acting in the tridentate form. The Ag-P and Ag-N bond distances in {[HB(3,5-Me(2)pz)(3)]Ag(PPh2Me)} are 2.336(2) Angstrom and 2.316(6), 2.336(5) and 2.329(6) Angstrom, respectively; they are shorter than in the more sterically hindered {[HB(3,5-Me(2)pz)(3)]Ag(P-o-tolyl(3))} (Ag-P: 2.375(2) Angstrom; Ag-N: 2.361(4) Angstrom). The ligand bite N-Ag-N ranges from 82.1(2)degrees to 84.8(2)degrees, whereas the N-Ag-P angle ranges from 125.1(1) to 134.1(1)degrees. (C) 1998 Elsevier Science Ltd. All rights reserved.