Nitrogen-Based Ligands in the Coordination Sphere of Bismuth
摘要
The heavy bismuth, a metal, and the light nitrogen, a non-metal, both elements of the 15th group of the periodic table of the elements, do not occur in nature in a binary compound. In addition to sulfidic and oxidic bismuth ores, there is even elemental bismuth in nature, but no natural bismuth–nitrogen compounds, so it is not surprising that bismuth–nitrogen chemistry is only a marginal field of chemical research. This is certainly due to the fact that nitrogen, with its thermodynamically stable triple bond, is too inert to combine under standard conditions directly with bismuth like oxygen or sulfur. Bismuth–nitrogen chemistry therefore only slowly developed late in the twentieth century. Bismuth(III)–nitrogen chemistry in particular was developed, while bismuth(V) nitrogen chemistry is still in its infancy. This article focuses on nitrogen-rich bismuth(III) compounds with direct Bi–N bonds. This includes the chemistry of bismuth azides, nitrides, and amides. Particular attention is paid to synthesis, structure and chemical bonding, whereby unusual structural and bonding situations are critically examined and their interpretation critically scrutinized. Both tri- and di-coordinated Bi–N compounds are discussed, including Bi–N species with bismuth in unusual oxidation states such as +II. Although there is still no direct application for Bi–N compounds, the increasing number of reports on the activation of molecules and even catalysis by bismuth compounds is bringing bismuth compounds in general, and thus also Bi–N compounds, increasingly into focus.