Insights into metal borohydride and aluminohydride bonding: X-ray and neutron diffraction structures and a DFT and charge density study of [Na(15-crown-5)][EH(4)] (E = B, Al).

The neutron and X-ray structures of [Na(15-crown-5)][BH(4)] and [Na(15-crown-5)][AlH(4)], respectively, are reported, along with a topological analysis of their DFT-computed charge densities that explores the bonding between the anionic complex hydride [EH(4)](-) (E = B, Al) and the counterion [Na(15-crown-5)](+). In each case, the interaction is weak and mainly electrostatic in nature; however, notable differences are observed in the manner in which [BH(4)](-) and [AlH(4)](-) bind to the metal, which explains their different coordination modes. A range of unconventional E-H···H-C contacts is revealed to play an important role in the overall bonding and crystal packing of both complexes.

Can P-H sigma-bond complexes be prepared? A computational study by DFT and AIM methods.

A series of complexes of general formula [CpMn(CO)(2)(eta(2)-HPR(1)R(2).BCl(3))] has been studied by DFT calculations and topological analyses of the charge density thus derived. The 21 complexes included in this study exhibit closely similar Mn-H-P geometries, in spite of a wide range of substituents (R(1); R(2)) at the phosphorus atom.

A structural study of [CpM(CO)3H] (M = Cr, Mo and W) by single-crystal X-ray diffraction and DFT calculations: sterically crowded yet surprisingly flexible molecules.

The single-crystal X-ray structures of the complexes [CpCr(CO)3H] 1, [CpMo(CO)3H] 2 and [CpW(CO)3H] 3 are reported. The results indicate that 1 adopts a structure close to a distorted three-legged piano stool geometry, whereas a conventional four-legged piano stool arrangement is observed for 2 and 3. Further insight into the equilibrium geometries and potential energy surfaces of all three complexes was obtained by DFT calculations.