Fluorinated and B-Vinylated Tris(pyridyl)borate in Copper(I) Coordination Chemistry

Abstract

Fluorinated tris(pyridyl)borate with a vinyl substituent on boron was synthesized and comprehensively characterized, expanding the diversity and functional versatility of the poly(pyridyl)borate ligand family. The coordination chemistry of this ligand with copper(I) was investigated in the presence of ethylene, carbon monoxide, and triphenylphosphine ligand auxiliaries. Single-crystal X-ray diffraction studies revealed distinct coordination environments, with the vinyl group directly coordinating to copper in the solid-state structures of the CO and PPh₃ complexes, while it remains free in the ethylene complex. Room-temperature NMR spectroscopy indicated the presence of two isomers—metal-coordinated and free vinyl species—in CDCl₃ solutions of the ethylene and carbonyl complexes. Phosphine complexes show the presence of only one isomer in CDCl₃ solution at room temperature. These results emphasize the potential of using additional functionalities on the boron of poly(pyridyl)borate ligands to adjust the electronic and structural properties of metal coordination complexes, providing useful design principles for their application. We also demonstrate the use of a user-friendly vinyl-boron precursor for the ligand assembly.