Coordination of nitroxyl radical probes to the Lewis acid sits on the surface of gallium oxide: a quantum-chemical analysis

摘要

The results of ESR investigations of quantum-chemical studies on the coordination of 2,2,6,6-tetramethylpiperidine-N-oxyl to the Lewis acid sites (LAS) on the surface of gallium oxide are reported and analyzed. The structural, spin, electrostatic, and energy charactreistics of the coordination of the simplest nitorxyl radical, H_2NO~*, to the Ga(OH)_3 model cluster-type LAS were calculated by the unrestricted Hartee-Fock method in the 6-31G basis set and using the semiempirical PM3 approximation. The properties of gallium-containing nitroxyl surface complexes and their aluminum-containing analogs are compared. According to the results of cluster quantum-chemical calculations, the LAS on the surface of gallium oxide are stronger than those on the alumina surface.