67605-95-2Relevant academic research and scientific papers
Photochemistry of nitrogen ligand substituted dinuclear rhenium carbonyl compounds
Gard, David R.,Brown, Theodore L.
, p. 1143 - 1147 (2008/10/08)
The reactions of eq-Re2(CO)9 L (L = CH3CN, pyridine, CH3NH2, or CaHgNH2) and of 1,2-eq,eq-Re2(CO)8L2 (L = CH3CN, pyridine (py)) have been examined under sunlamp irradiation. 1,2-eq,eq-Re2(CO)8(CH3CN)2 is observed as the primary photoproduct under continuous photolysis of Re2(CO)9(CH3CN). Re4(CO)12(OH)4 is formed from a side photochemical reaction of the CH3CN compounds with residual H2o in the THF or heptane solvent. The initial rhenium-containing products of the photochemical reaction of eq-Re2-(CO)9(pyridine) or of 1,2-eq,eq-Re2(CO)8(pyridine)2 under continuous photolysis in THF are Re2(CO)10, Re(CO)3(py)3+, HRe4(CO)16-, and 1,1-(μ-H)Re2(CO)7(py)(NC5H4) (formed in similar yields with either starting compound). Flash irradiation of eq-Re2(CO)9(py) in THF allows detection of the intermediate 1,2-eq-eq-Re2(CO)8(py)2·(μ-H)Re 2(Co)8(NC6H4) can be prepared in a thermal reaction from 1,2-eq,eq-Re2(CO)8(py)2. It reacts slowly with pyridine to yield 1,1-(μ-H)Re2(CO)7(py)(NC5H4). Photolysis of eq-Re2(CO)9(RNH2) (R = CH3, C2H5) in heptane yields Re2(CO)10 and a precipitate of 1,1-Re2(CO)8(RNH2)2. Mechanisms are proposed for the photochemical reactions of the nitrogen-base compounds. The primary photoprocess in all cases is homolytic cleavage of the Re-Re bond. Loss of CO or L from the Re(CO)4L· radicals allows formation of Re(CO)5· and Re(CO)3L2· species. The rate of dissociation of L from photogenerated Re(CO)4L· appears to be comparable to that of CO. Analogies to the photochemical reaction of Re2(CO)10 with H2o are noted.
