Investigations on synthesis, structural characterization, and new pathway to the butterfly [2Fe2Se] cluster complexes

As a continuation of our studies on butterfly [2Fe2S] cluster chemistry, two new N-functionally substituted butterfly [2Fe2Se] cluster complexes 1 and 2 have been first synthesized by the condensation pathway and in satisfactory yields. Reaction of Fe2(SeH)2(CO)6 and aqueous formaldehyde affords the possible intermediate Fe2(SeCH2OH)2(CO)6. While the intermediate Fe2(SeCH2OH)2(CO)6 reacts with Glycine (NH2CH2CO2H) or (BocNH-p)C6H4NH2, to produce [(μ-SeCH2)2NCH2CO2H]Fe2(CO)6 (1) and [(μ-SeCH2)2NC6H4(p-NHBoc)]Fe2(CO)6 (2) in satisfactory yield. This synthesis route is found to be an efficient pathway to produce the N-functionally substituted butterfly [2Fe2Se] cluster complexes. As new complexes, both 1 and 2 have been characterized by elemental analysis and spectroscopy, as well as for 1 by X-ray crystallography.