SOLUTION PHOTOSUBSTITUTION CHEMISTRY OF AMINE PENTACARBONYL DERIVATIVES OF GROUP 6B METALS IN PRESENCE OF CO-13 - EXAMPLE OF STEREOSPECIFIC INCORPORATION OF CO-13

The ligand photosubstitution chemistry of M(CO)5(amine) derivatives (M=Cr, Mo, W; amine=piperidine, pyridine) in the presence of 13C-labeled carbon monoxide has been demonstrated to involve both CO and amine loss at 366 and 313 nm. The relative quantum yields for CO vs. unique ligand (amine) dissociation were found to be highly dependent on the metal center, with the chromium complexes exhibiting a greater propensity for CO dissociation as opposed to amine loss. On the other hand, molybdenum and tungsten were shown (consistent with and as an extension of previous studies) to undergo amine dissociation with a greater quantum efficiency than CO loss. More importantly, it has been clearly established that for the process involving CO photosubstitution with 13CO the products are stereospecifically labeled metal pentacarbonyl derivatives, cis-M(CO)4(13CO)(amine). These experiments demonstrate that there is either exclusively equatorial carbonyl photosubstitution occurring (affording a Cs intermediate) or a facile rearrangement of the C4v form of the intermediate, [M(CO)4(amine)], to the Cs structure prior to recombination with an incoming 13CO ligand. 1978, American Chemical Society. All rights reserved.

SOLUTION PHOTOSUBSTITUTION CHEMISTRY OF AMINE PENTACARBONYL DERIVATIVES OF GROUP 6B METALS IN PRESENCE OF CO-13 - EXAMPLE OF STEREOSPECIFIC INCORPORATION OF CO-13 Academic Article