Structural diversity of copper, silver, and gold complexes supported by a fluorinated B-methylated tris(pyridyl)borate.

The coordination chemistry of the fluorinated, B-methylated tris(pyridyl)borate ligand with coinage-metal centers Cu(I), Ag(I), and Au(I) bearing triphenylphosphine and tert-butyl isocyanide co-ligands is described. The complexes [MeB(6-(CF3)Py)3]M(PPh3) and [MeB(6-(CF3)Py)3]M(CNtBu) were synthesized in good yields and fully characterized by multinuclear NMR and IR spectroscopy, as well as single-crystal X-ray diffraction. The tris(pyridyl)borate ligand exhibits systematic variations in denticity governed by both the metal center and the ancillary ligand. Bulky PPh3 enforces κ2 coordination in trigonal-planar Cu(I) and Ag(I) complexes, but κ1 coordination in linear Au(I) species. In contrast, the smaller CNtBu ligand enables κ3 coordination, affording tetrahedral Cu(I) and Ag(I) complexes and a pseudo-κ2, distorted T-shaped Au(I) derivative. Together with previously reported CO (κ3) and ethylene (κ2) analogs, these findings demonstrate that the steric and electronic properties of the terminal ligand effectively modulate binding modes across the coinage-metal triad. Some of the fluorinated systems exhibit informative through-space 31P-19F and Ag-F NMR couplings. Density functional theory (DFT) and energy decomposition analysis using natural orbitals for chemical valence (EDA-NOCV) reproduce the observed structures and indicate that the interactions are predominantly electrostatic. These results establish [MeB(6-(CF3)Py)3]- as a robust and versatile platform with flexible coordination modes for tuning coordination environments in coinage-metal complexes.