Two Novel Bridgehead-C-Substituted Diiron Propanedithiolate Complexes as Active Site Models for Fe-Only Hydrogenases

The two novel diiron propanedithiolate model compounds [Fe2(μ-CH2SMe)(μ-SCH2)(CO)6][Fe2(μ-SCH2)2CMe(CO)6] (3) and [Fe2(μ-CH2CHCH2)(μ-SCH2)(CO)6][Fe2(μ-SCH2)2CMe(CO)6] (4) have been unexpectedly obtained through a “one-pot” route by reaction of the trithiol MeC(CH2SH)3 with Fe3(CO)12 in the presence of Et3N, followed by treatment with MeSCH2Cl and CH2CHCH2Br, respectively. The structures of 3 and 4 have been fully characterized, and the possible pathway for formation of 3 and 4 is suggested. In addition, some electrochemical properties of 3 related to the H2 evolution function of Fe-only hydrogenases are also reported.