PHOTOCHEMISTRY OF INDENYLIRON DICARBONYL DISILANES, (ETA(5)-C9H7)FE(CO)(2)SI(2)ME(2)PH(3), INVOLVING ISOMERIZATION, EG (2)SIPH(3)-](ETA(5)-C9H7)FE(CO)(2)SIMEPHSIMEPH(2), PRIOR TO SILYLENE ELIMINATION

A series of triphenyl(dimethyl)disilane isomers substituted with inden yliron dicarbonyl, (eta(5)-C9H7)Fe(CO)(2)Si(2)Me(2)Ph(3), have been sy nthesized and characterized. Photochemical treatment of the complexes in inert hydrocarbon solvents ultimately resulted in the formation. of the appropriate monosilyl complexes, (eta(5)-C9H7)Fe(CO)(2)SiMe(n)Ph( 3-n) (n = 0-2) via the elimination. of silylene fragments. However, co ntrary to the results previously obtained with the cyclopentadienyl an alogs, (eta(5)-C5H5)Fe(CO)(2)Si(2)Me(n)Ph(5-n), isomerization. of the disilanes was observed prior to silylene elimination. The chemistry, w hich takes place via equilibrating intermediate silyl(silylene)iron co mplexes, e.g. (eta(5)-C9H7)Fe(CO)(=SiMe(2))SiPh(3), indicates that sil ylene elimination, a photochemical event, is extremely sensitive to th e nature of the ligands bonded to the transition metal. 1,3-Alkyl-(ary l) shifts coupled with the recombination of the silicon-silicon bond t hat lead to isomerization. occur more rapidly than. the silylene elimi nation in the indenyliron, complexes.