1,1-bis(1 '',2 '',3 '',4 '',5 ''-pentamethylferrocen-1 '-yl)ethene

1,1-Bis(1 ",2 ",3 ",4 ",5 "-pentamethylferrocen-1'-yl)ethene (6) was synthe zised as a prototype of two metallocenes that are bridged by the sp(2)-carb on center of a vinylidene group. Starting from 6-N,N-dimethylamino-6-methyl fulvene, the iron-containing intermediates were a pentamethylferrocenyl-sub stituted fulvene and an ethene that was geminally disubstituted by a Cp ani on and a pentamethylferrocenyl moiety. Besides other methods, the ferrocene s were characterized by NMR spectroscopy including full signal assignment. The bimetallic compound 6 showed moderate interactions between the two ferr ocenes in the cyclic voltammogram (Delta E-1/2 = 150 mV). According to X-ra y crystal structure analysis compound 6 is a twisted molecule; the vinylide ne moiety and the Cps of the neighboring ferrocenes are not coplanar. (C) 1 999 Elsevier Science S.A. All rights reserved.