Synthesis, structure and formation pathways of new Fe–S complexes containing [Fe2S2]-units in different valences, [Fe2S2(CO)4(PPh3)2], [Fe3S2(CO)6(PPh3)3] and [Fe4S2(CO)10]2− and the origin of the [Fe2S2]-unit in metal–[Fe2S2(CO)6] complexes
摘要:
Novel Fe-S cluster complexes, [Fe2S2(CO)(4)(PPh3)(2)] (1), [Fe3S2(CO)(6)(PPh3)(3)] (2) and [Ph4P](2)[Fe4S2(CO)(10)] (3) have been synthesized by the reaction of LiEt3BH with [Fe2S2(CO)(6)] in the presence of CuCl-PPh3, AgNO3-PPh3 and CuClO3-MeCN, respectively. Structure determination indicated that 1, 2 and 3, respectively, possessed [Fe2S2](0) core with [Fe2S2](0)-unit, [Fe3S2](0) with [Fe2S2](2-) and [Fe4S2](2-) core with [Fe2S2](4-) unit, which implied that [Fe2S2(CO)(6)](2-), as a starting material, underwent a disproportionation in the synthetic reaction. Investigating the structure and synthetic reaction, an origin of the different valence[Fe2S2]-units and formation pathways of those clusters via disproportionation of the [Fe2S2(CO)(6)](2-) following by 'Unit Construction' were proposed and discussed. (C) 2004 Elsevier B.V. All rights reserved.