The Effect of Carborane Substituents on the Lewis Acidity of Boranes

Abstract

The Lewis acidity of primary, secondary, and tertiary boranes with phenyl, pentafluorophenyl, and all three isomers of icosahedral carboranes (ortho, meta, and para) were investigated by computing their fluoride, hydride, and ammonia affinities as well as global electrophilicity indices and LUMO energies. From these calculations, the substituent effects on the Lewis acidity follow the trend of ortho-carborane > meta-carborane > para-carborane > C6F5 > C6H5.