Advances and recent trends in dipnictenes chemistry

Abstract

Dipnictenes are molecules comprising a double bond between two Group 15 elements (referred as pnictogens (Pn) = P, As, Sb, Bi). Over the last decades, the chemistry of dipnictenes has undergone a remarkable advance. This is largely because of the advancement of new ligand sets with distinct stereoelectronic properties. In general, classical dipnictenes are kinetically stabilized by the use of extremely bulky aryl or alkyl substituents. In recent years, numerous ligand frameworks featuring non-carbon donor substituents have also been introduced in dipnictenes chemistry. Now a plethora of dipnictenes with divergent electronic structure, reactivity, and physical properties are known. Among carbon-donor substituents, stable N-heterocyclic carbenes (NHCs) and other singlet carbenes have also been used as potent Lewis bases to derive related unsaturated species. A comprehensive understanding of the structure, bonding, and reactivity of a whole series of dipnictenes (RPn=PnR) (R = a substituent) as well as the influence of substituents on the nature of these species will be instrumental for the advancement of the field, in particular to unveil the relevance of these molecules in materials science. The aim of this review is to outline recent advances in dipnictene chemistry with a special focus on their reactivity. The outcomes show that dipnictenes have emerged from simple laboratory curiosities to versatile and useful synthons in modern main-group chemistry, which is expected to evolve further.