An unambiguous electron-counting notation for metallaboratranes

Abstract

A cohesive notation for indicating the overall number of electrons associated with metallaboratanes and metal-boron (M-B) dative unit that eliminated confusion arising from electron-counting formalisms was investigated. Metallaboratanes are a new class of compound in which a metal-boron dative is housed within a cage or chelated structure and the majority of such complexes were developed from investigations of the chemistry of poly(methimazolyl) borates. It is anticipated that as the field of metallaboratanes develops, a spectrum of behavior for the M-B bond will emerge, involving different degrees of electron transfer from the metal to the Lewis acid. The results of computational studies of the two metallaboratanes are distinct to provide a gradation of M-B dative interactions. It is expected that more subtleties will emerge from computational studies of metallaboratanes, with several factors contributing to the Lewis basicity of a transition metal.