Novel thermal rearrangement reactions: rearrangement stereospecificity of complex [Fe-2(CO)(2)(mu-CO)(2)(mu-t-BuC5H3-Me2GeGeMe2C5H3Bu-t)]

Thermal treatment of 1,2-bis(3-tert-butylcyclopentadienyl)tetramethyldigerm ane with [Fe(CO)(5)] in xylene gave the diiron complex [Fe-2(CO)(2)(mu-CO)( 2)(mu-3-t-BuC5H3Me2GeGeMe2C5H3Bu-t-3)] 1 existing as a mixture of cis and t rans isomers (1c and 1t) which were separated by preparative TLC. When the two isomers were heated in xylene the cis substrate (1c) rearranged to a tr ans product [Fe-2(CO)(4)(mu-3-t-BuC5H3GeMe2)(2)] 2t, while the trans substr ate (1t) afforded a tis product 2c. This indicates that the rearrangement r eaction is stereospecific, which is consistent with previous results. Molec ular structures of 1c, 1t, 2t, and 2c were determined by X-ray diffraction.