Hydrogen gas formation from the photolysis of rhenium hydrides - mechanistic and computational studies.

The photolysis of 4,4'-disubstituted, 2,2'-bipyridine fac-Re(bpy)(CO)H derivatives produces stoichiometric H gas. The rate of production varies greatly depending on the electronic nature of the disubstituted bipyridine (bpy) with halogenated substituents increasing the rate. Isotope labeling studies along with B3LYP geometry optimization DFT modeling studies indicate a mechanism involving a Re-H-Re bridging complex that leads to a dimeric Re-Re(η-H) state prior to dissociating H gas.

First-row transition-metal chloride complexes of the wide bite-angle diphosphine (iPr)DPDBFphos and reactivity studies of monovalent nickel.

The diphosphine 4,6-bis(3-diisopropylphosphinophenyl)dibenzofuran (abbreviated as (iPr)DPDBFphos) has been metalated with transition metal dichlorides of zinc, cobalt, and nickel to yield ((iPr)DPDBFphos)MCl(2) complexes. Within these compounds, the diphosphine (iPr)DPDBFphos adapts a wide range of bite angles (115 to 180°) as determined by X-ray crystallography. A three-coordinate planar Ni(I) species was isolated from the reduction of ((iPr)DPDBFphos)NiCl(2) with KC(8).