First hyperpolarizability of 6-vertex carboranes 2. DFT study of NH 2 /NO 2 -substituted 1,2-closo-dicarbahexaboranes

Abstract

The structure and molecular first hyperpolarizability (β) of the nitro-amino-substituted 1,2-dicarba-closo-hexaboranes were investigated at B3LYP/6-31+G(d) level of theory. Conformations with different orientations of the substituents with respect to the carborane cage were considered. It is shown that two factors significantly influence the value of β: orientation of the amino- and nitro-group with respect to the cage, and their mutual orientation. The latter factor appears to be more important. The results obtained have revealed that a carborane substituted at boron atoms is characterized by higher value of the molecular first hyperpolarizability.