Synthesis, electrochemical and theoretical studies of the Au(I)-Cu(I)heterometallic clusters bearing ferrocenyl groups

摘要

Treatment of the polymeric alkynyl compounds (AuC_2R)_n(R = Fc, C_6H_4Fc; Fc = ferrocenyl) with thediphosphine PPh_2C_6H_4PPh_2gave complexes (RC_2Au)PPh_2C_6H_4PPh_2(AuC_2R) (1, R = Fc; 2, R =C_6H_4Fc) with end-capped ferrocenyl groups. The reactions of 1 or 2 with Cu(NCMe)_4PF_6result information of the heterotrimetallic aggregates [{Au_3Cu_2(C_2R)_6}Au_3(PPh_2C_6H_4PPh_2)_3](PF_6)_2(3, R = Fc;4, R = C_6H_4Fc), which consist of the alkynyl clusters [Au_3Cu_2(C_2R)_6]- "wrapped" by the cationic[Au_3(PPh_2C_6H_4PPh_2)_3]~(3+) "belt". The novel compounds were characterized by NMR spectroscopy andESI-MS measurements. The solid state structure of 3 is reported. Electrochemical properties of thecomplexes 1-4 have been studied. These data show that all six ferrocenyl units are oxidized in theclusters 3 and 4. The Fc groups of 3 are electronically coupled into each other, but in 4 behaveessentially independently. Electronic structure calculations have been performed, showing goodcorrelation with the X-ray and electrochemical studies.