1,1‘-Bis(dimethylvinylsilyl)ferrocene as a Two-Directional Core for the Construction of Homo- and Heterometallic Systems

The divinyl derivative Fe[(η 5 -C 5 H 4 )(Me 2 SiCH CH 2 )] 2 ( 1 ), prepared by the low-temperature reaction of 1,1‘-dilithioferrocene·TMEDA with ClSiMe 2 (CH CH 2 ), has been used as a readily functionalizable core unit for the synthesis of multimetallic systems. The hydrosilylation reaction of 1 with Cl 2 MeSiH and Ph 2 MeSiH provides the tetrafunctional ferrocenes Fe[(η 5 -C 5 H 4 )(SiMe 2 (CH 2 ) 2 SiMeCl 2 )] 2 ( 2 ) and Fe[(η 5 -C 5 H 4 )(SiMe 2 (CH 2 ) 2 SiMePh 2 )] 2 ( 5 ), which after reaction with Fe(η 5 -C 5 H 4 Li)(η 5 -C 5 H 5 ) and Cr(CO) 6, respectively, afforded the pentametallic molecules Fe[(η 5 -C 5 H 4 )(SiMe 2 (CH 2 ) 2 SiMeFc 2 )] 2 ( 3 ) (Fc = (η 5 -C 5 H 4 )Fe(η 5 -C 5 H 5 )) and Fe[(η 5 -C 5 H 4 )(SiMe 2 (CH 2 ) 2 SiMe{(η 6 -C 6 H 5 )Cr(CO) 3 } 2 )] 2 ( 6 ). Characterization of the synthesized molecules by 1 H, 13 C, and 29 Si NMR and IR spectroscopy, mass spectrometry, and elemental analysis supports their assigned structures. The electrochemical behavior has been studied. While 3 contains two pairs of outer silicon-bridged ferrocenyl units, in which the iron centers interact with one another, in the related 6 the chromium tricarbonyl groups complexed to arene rings, also joined by a single silicon, are essentially noninteracting.