Lithium, Tin(II), and Zinc Amino-Boryloxy Complexes: Synthesis and Characterization

Abstract

Analogous to the ubiquitous alkoxide ligand, metal boroxide and boryloxy complexes are an underexplored class of hard anionic O − ligand. A new series of amine-stabilized Li, Sn(II), and Zn boryloxy complexes, comprising electron-rich tetrahedral boron centers have been synthesized and characterized. All complexes have been characterized by one-dimensional (1D), two-dimensional (2D), and DOSY NMR, which are consistent with the solid-state structures unambiguously determined via single-crystal X-ray diffraction. Electron-rich μ 2 -(Sn and Zn) and μ 3 -(Li) boryloxy binding modes are observed. Compounds 6−9 are the first complexes of this class, with the chelating bis-and trisphenol ligands providing a scaffold that can be easily functionalized and provides access to the boronic acid pro-ligand, hence allowing facile direct synthesis of the resulting compounds. Computational quantum chemical studies suggest a significant enhancement of the π-donor ability of the amine-stabilized boryloxy ligand because of electron donation from the amine functionality into the porbital of the boron atom.

Zinc and cadmium thioamidate complexes: rational design of single-source precursors for the AACVD of ZnS

“…87,88 We have also previously reported using 1 H DOSY to calculate the estimated molecular weights of zinc phosphate complexes. 89 Previous AACVD studies have shown that organic solvents capable of metal-coordination (e.g., THF or diethyl ether) as well as those non-coordinating (e.g., toluene) can significantly affect the deposition process as well as thin film morphology. 30,90,91 Therefore, 1 H DOSY studies were carried out on these compounds in representative solvents, CDCl 3 and THF-d 8 .…”