Molecular orbital model of the influence of interaction between O2 and aluminosilicate sites on the triplet-singlet energy gap and reactivity.

The behavior of O(2) molecule in models of acid aluminosilicate sites on any kind of material was investigated using reliable QM ab initio calculations. The triplet-singlet energy gap of isolated O(2) was calculated at confident levels of theory with different basis sets as a reference. Models of aluminosilicate active sites interacting with oxygen in their singlet and triplet electronic states were considered for two kinds of O(2) arrangements. Geometry optimizations were performed on both non-corrected and corrected BSSE potential energy surfaces, realizing that good modeling of heavy atom-hydrogen interactions is sensitive to BSSE corrections during these processes. Energies were further evaluated at higher level of theory to test tendencies. Singlet oxygen appears more attractive to active aluminosilicate sites than those calculated with triplet oxygen, indicating a source of oxidative efficiency for designed nanostructures containing such molecular residues. It was clearly seen that aluminosilicate groups, appearing ubiquitously in several materials, could reduce the O(2) triplet-singlets energy gap by at least 10 kJ/mol. Some elegant features of oxygen interactions with such sites were further analyzed by means of the atoms in molecules (AIM) theory.