Hydrogen and silyl bridges in group 13 and 14 atom containing molecules.

Group 13 and group 14 atom containing small hydrides were investigated by quantum chemical methods to characterize their possible nonclassical bridged isomers. A robust set of methods were used like NBO analysis, topological analysis of ELF, AIM theory, several bond indices (Mayer bond order, fuzzy atoms bond order, Wiberg bond index, atom–atom overlap weighted NAO bond order), and geometry. The hydrogen bridges can be interpreted by 2 electron – 3 center bonds in NBO analysis, trisynaptic X1-Hb-X2 valence cores in ELF, and two X-Hb bond critical points in AIM theory. The bond orders of the X-Hb bonds are always around half of that in a classical bond, and the sum of the bond orders for the two bridging bonds is always around one. Bonding interaction between the pillar X1-X2 atoms exists in several cases, suggested by NBO analysis, ELF, the geometry and the bond orders. In the AIM picture, however, the X1-X2 pillar bond or one of the X-Hb bridging bond is missing. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 [ABSTRACT FROM AUTHOR]