| Abstrakt: |
The synthesis and characterization of two bulky ferrocenyl-functionalized amidinates and their lithium, potassium, rhodium(I), and iridium(I) complexes are reported. The ferrocenyl mono(amidine) [Fc{C(NDipp)(NHDipp)}] (1) (Fc = ferrocenyl; Dipp = 2,6-diisopropylphenyl) and its potassium complex [Fc{C(NDipp)2K}·3THF] (2) as well as the 1,1′-ferrocendiyl-bridged bis(amidinate) [fc{C(NMes)2Li}2·3THF] (3) (fc = ferrocene-1,1′-diyl; Mes = mesityl) were synthesized. Salt metathesis reactions with the metal precursors [Rh(cod)Cl]2(cod = 1,5-cyclooctadiene) and [Ir(cod)Cl]2gave the rhodium(I) and iridium(I) complexes [Fc{C(NDipp)2Rh(cod)}] (4), [fc{C(NMes)2Rh(cod)}2] (5), and [fc{C(NMes)2Ir(cod)}2] (6), as well as the ortho-metalated compound [(Cp)Fe(C5H3){C(NHDipp)(NDipp)Ir(cod)}] (7). As complex 7showed an ortho-metalation on the ferrocene backbone, we investigated this reaction in more detail. It was found that the rhodium(I) complexes 4and 5also undergo ortho-metalation upon treatment with carbon monoxide (CO). After the carbonylation, the first known ortho-metalation of rhodium(I) on ferrocene complexes was observed for [(Cp)Fe{(C5H3)C(NHDipp)(NDipp)Rh(CO)2}] (8) and [Fe(C5H3)2{C(NHMes)(NMes)Rh(CO)2}2] (9). A combined electrochemical and quantum chemical study revealed that depending on both the metal-bound ligand (CO vs cod) and the bonding mode (κ2Nvs ortho-metalated), the highest occupied molecular orbital is located more on iron or on rhodium/iridium. |
