Thermal Ring Contraction of 1,2-Digermacyclohexadienes Coordinated with Iron Tricarbonyl Fragment
1,1,2,2-Tetraalkyl-3,6-diphenyl-1,2-digermacyclohexa-3,5-dienes (1) reacted with iron pentacarbonyl to give the corresponding tricarbonyl(η4-1,1,2,2-tetraalkyl-3,6-diphenyl-1,2-digermacyclohexa-3,5-diene)iron (2). Heating 2 caused extrusion of dialkylgermylenes to give (η4-1,1-dialkyl-2,5-dipenyl-1-germacyclopenta-2,4-diene)tricarbonyliron (3). The structures of the (diene)iron tricarbonyls were deterimined by X-ray crystal structure analysis.