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

摘要

Reaction of[Mo2(O2CR)4](R=CF3,1)with TCNE in toluene affords the new compound[Mo2(O2CCF3)4(TCNE)]·2C6H5CH3(2).The structure of 2 is built on[Mo2(O2CCF3)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 Mo2 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.