Quadruply-bonded dimolybdenum compounds: reactivity towards TCNE. Structural evidences for the 1-D polymer [{Mo2(O2CCF3)4}(TCNE)]∞

Abstract Reaction of [Mo 2 (O 2 CR) 4 ] (R = CF 3 , 1 ) with TCNE in toluene affords the new compound [Mo 2 (O 2 CCF 3 ) 4 (TCNE)]·2C 6 H 5 CH 3 ( 2 ). The structure of 2 is built on [Mo 2 (O 2 CCF 3 ) 4 ] fragments having the usual paddlewheel structure of 1 (Mo–Mo 2.1117(8) A) and TCNE units. Each polynitrile moiety acts as a bridging ligand between two Mo 2 fragments (Mo–N 2.875(4) A) affording 1-D polymeric chains crossing in the crystal; the toluene molecules occupy the cavities between the chains. 13 C NMR, IR and electrochemical data clearly show that formation of 2 does not involve electron density transfer from dimolybdenum fragment to the TCNE unit, which remains in 2 in its neutral state. To cite this article: B. Le Gall et al., C. R. Chimie 8 (2005)