Silver(I)-organophosphane complexes of electron withdrawing CF3- or NO2-substituted scorpionate ligands

New silver(I) complexes have been synthesized from the reaction of AgNO3, monodentate tertiary phosphanes PR3 (PR3 = P(C6H5)(3), P(o-C6H4CH3)(3), P(m-C6H4CH3)(3), P(p-C6H4CH3)(3), PCH3(C6H5)(2)) and two novel electron withdrawing ligands: potassium dihydrobis(3-nitropyrazol-1-yl) borate and potassium dihydrobis(3-trifluoromethylpyrazol-1-yl) borate. These compounds have been characterized by elemental analyses, FT-IR, ESI-MS and multinuclear (H-1, F-19 and P-31) NMR spectroscopy. Solid state structures of the potassium salts K[H2B(3-(NO2) pz)(2)] and K[H2B(3-(CF3) pz)(2)] have been reported. They form polymeric networks due to intermolecular contacts of various types between the potassium ion and atoms of the neighboring molecules. The silver adducts [H2B(3-(NO2) pz)(2)] Ag[P(C6H5)(3)](2) and [H2B(3-(NO2) pz)(2)] Ag[P(p-C6H4CH3)(3)] have pseudo tetrahedral and trigonal planar silver sites, respectively. The bis(pyrazolyl) borate ligand acts as a kappa(2)-N-2 donor. The nitro-substituents are coplanar with the pyrazolyl rings in all these adducts indicating efficient electron delocalization between the two units. The [H2B(3-(CF3) pz)(2)] Ag[P(C6H5)(3)] complex has been obtained from re-crystallization of {[H2B(3-(CF3) pz)(2)] Ag[P(C6H5)(3)](2)} in a dichloromethane - diethyl ether solution; it is a three-coordinate, trigonal planar silver complex.