Rhenium allenylidenes

After these initial studies, the most recent developments in Group 7 allenylidene chemistry concern rhenium. Thus, the cationic octahedral Re(I) derivatives 6 [98, 99], 7 [100], and 8 [1011 have been conveniently prepared by following the Selegue s synthetic approach (Fig. 4). In addition, starting from appropriate bis-alkynols, several homo- and hetero-bimetal lie derivatives 9-10, in which two allenylidene groups are held together by an organic spacer, could also be synthesized [102]. 

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