The σ2π4 Triple Bond between Molybdenum and Tungsten Atoms: Developing the Chemistry of an Inorganic Functional Group

Numerous analogies between organic and inorganic chemistry have emerged in recent years. The most prominent example is the isolobal relationship. Many reactions have shown that metal‐metal double and triple bonds exhibit a pattern of reactivity similar to that of alkenes and alkynes. In compounds containing a σ2π4 triple bond between molybdenum and tungsten atoms, the MM bond order can be increased from three to four by reductive elimination or decreased from three to two or one by oxidative addition. Complexes with MM bonds can be used to prepare clusters or can serve as catalysts. In this review relationships between structure (electronic and stereochemical) and reactivity that are characteristic for modern inorganic chemistry are discussed.