Rings Compounds of Boron and Phosphorus

Abstract

The synthesis and characterization of some ring systems of phosphorus and boron are described. Ring systems of boron such as boroxines, silylboranes, and diborabenzenes are considered. The structural and spectroscopic data for the ring derivatives support varying degrees of electron delocalization, depending on the size of the ring. Ring systems of phosphorus such as phosphenium ions and diphosphorus cations are outlined. The importance of P-C π-bonding interactions and the heterocyclic frameworks in the stabilization of these compounds are highlighted. Finally, new heterocyclic organoboranes are reported, which result from reductions of RBX₂ and with alkalai metals. All the rings and their respective derivatives have been characterized spectroscopically and the solid-state structures of some representative members were determined by X-ray crystallography. The degree of delocalization in the pertinent ring complexes are compared with theoretical models.