Access to Silver–Bismuth and Lighter Pnictogen Complexes with a Fluorinated Tris(pyrazolyl)borate

Abstract

Unsupported Ag–Bi interactions are exceedingly rare due to the poor donor ability of bismuthines. Using the highly fluorinated tris(pyrazolyl)borate ligand, we have isolated and characterized the silver(I) bismuthine complexes [HB(3,5-(CF3)2Pz)3]Ag(BiMes3) and [HB(3,5-(CF3)2Pz)3]Ag(BiPh3), together with the corresponding SbPh3 and AsPh3 analogues. X-ray diffraction studies reveal unsupported Ag–Bi bond distances that are substantially shorter than those previously reported. Structural and computational investigations show systematic Ag–E (E = P, As, Sb, Bi) bonding trends, with interaction energies decreasing down Group 15 in accordance with diminishing pnictogen donor strength. Energy decomposition analyses identify electrostatic attraction and pnictogen-to-silver σ-donation as the principal contributors to bonding. This work provides rare, well-defined examples of unsupported Ag–Bi bonding and expands the coordination chemistry of silver with heavier pnictogen donors.