SYNTHESIS OF BIMETALLIC CARBONYL-COMPLEXES OF MANGANESE, RHODIUM, AND RUTHENIUM FROM 1,4-BIS(CYCLOPENTADIENYLTHALLIUM)-1,4-BUTADIONE

1,4-Bis(cyclopentadienylsodium)-1,4-butadione was prepared from reaction of sodium cyclopentadienide and diethylsuccinate and converted into its thallium analog by metal exchange using thallium ethoxide. Reaction of the thallium reagent with BrMn(CO)5 yielded 1,4-bis(cymantrenyl)-1,4-butadione, while reaction with [ClRh(CO)2]2 gave both a bis(cyclopentadienylrhodiumdicarbonyl) complex and a small amount of a bis(cyclopentadienylrhodiumcarbonyl)-μ-carbonyl species. This latter material was found to undergo slow exchange on the NMR time scale which is believed to involve a side-to-side movement of both the μ-carbonyl and interring bridge. A complete variable temperature analysis of this motion was carried out. Reaction of the thallium reagent with [Cl2Ru(CO)3]2 resulted in the formation of a bis(cyclopentadienylrutheniumdicarbonyl) complex and small quantities of two other materials which have not yet been characterized. With the exception of these last two, all transition metal compounds have been fully characterized with Ir, 1H and 13C NMR, mass spectroscopy and elemental analysis. © 1990.