Synthesis and Characterization of 1,4-Diimine Complexes of 1,2,3,4,5-Pentamethylcyclopentadienylrhodium and Iridium

摘要

Monomeric rhodium and iridium diimine complexes Cp*M(HNRNH)(Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl : (M=lr; R=o-C6H4 (1a), 4,5-(CH3)2-C6H2-1,2 (1b), 4,5-(Cl)2-C6H2-1,2 (1c), NCC=CCN-1,2 (1d): M=Rh; R=NCC=CCN-1,2 (1e)) have been synthesized from [CP*MCl2]2 and 2 equiv. of diamine in the presence of NEt3. The Crystal structure of 1a was determined by X-ray diffraction method : 1a was crystallized in the monoclinic system, space group P21/c, with lattice constants a=9.543 (1) ∈, b=16.286 (1) ∈, c=10.068 (1) ∈ and モ=99.25 (1), with Z= 4. Least-squares refinement of the structure led to R factor of 0.049. The coordination sphere of rhodium and iridium can be described as a 2-legged piano-stool. All complexes are highly colored. Electrochemical studies show that 1d and 1e display quasi-reversible reduction and 1a-1c display irreversible reductions, suggesting that the acceptor orbital might be localized on the diimine ring.