57194-45-3Relevant academic research and scientific papers
Solid-state photochemical diag-lat isomerization of (η5-C5H4R)Re(CO)(L)X2 on the surface of silica gel
Cheng, Lin,Coville, Neil J.
, p. 591 - 596 (2008/10/08)
Room-temperature visible illumination (200 W light source) of diag-(η5-C5H4R)Re(CO)-(L)X2 (R = H, alkyl; L = CO, P(OR)3; X = Br, I) adsorbed on silica gel results in isomerization of the complexes into the corresponding lateral isomers in good yield (typically >80%). For L = CO, the isomerization reactions occurred in the direction reverse to that found in solution in which lat-to-diag isomerization was observed. It was found that the ratio of diagonal to lateral isomers established on the surface of silica gel was influenced by both X and L, viz. (η5-C5H4Me)Re(CO)[P(OR)3]Br 2 > (η5-C5H4Me)Re(CO)2Br2 > (η5-C5H4Me)Re(CO)2I2. Chemical removal of surface hydroxyl groups with Me2SiCl2 revealed that only a monolayer of the rhenium complex chemically adsorbed on the surface of the silica gel underwent isomerization. A mechanism to rationalize the role of the silica surface hydroxyl groups is described.
