Metal–metal bonds have been an interesting topic for many decades due to the fundamental studies in bonding properties, as well as potential applications in small molecule activation processes. Much of what is known about this area is mainly based on 2 and 3 row transitional metals. Understanding of the bonding behavior between first-row transition metals, however, is lacking due to the synthet...

Tetracoordinate planar carbon (that is, carbon atoms coordinated by four other atoms in a square-planar arrangement), first proposed by Hoffmann et al. over thirty years ago, was recently observed in the vibrationally averagedD4h [Al4C] , C2v Al3XC, [Al3XC] (X= Si,Ge), and [CAl4] 2 . Tetracoordinate planar (TP) Si and Ge centers were also discovered in MAl4 and [MAl4] . The TP bonding character...

A set of 41 metal-ligand bond distances in 25 third-row transition-metal complexes, for which precise structural data are known in the gas phase, is used to assess optimized and zero-point averaged geometries obtained from DFT computations with various exchange-correlation functionals and basis sets. For a given functional (except LSDA) Stuttgart-type quasi-relativistic effective core potential...