Diruthenium compounds bearing equatorial Fc-containing ligands: Synthesis and electronic structure
Previously, the synthesis of compounds Ru 2(D(3,5-Cl 2Ph)F) 4-n(O 2CFc) nCl (n = 1, 3a; 2, 4a), where D(3,5-Cl 2Ph)F is N,N′-di(3,5-dichlorophenyl) formamidinate, from the carboxylate exchange reactions between Ru 2(D(3,5-Cl 2Ph)F) 4-n(OAc) nCl and ferrocene carboxylic acid was communicated. Reported herein is the preparation of analogous compounds Ru 2(DmAniF) 4-n(O 2CFc) nCl (n = 1, 3b; 2, 4b), where DmAniF is N,N′-di(3-methoxyphenyl)formamidinate, from Ru 2(DmAniF) 4-n(OAc) nCl. Compounds 3 and 4 were characterized with various techniques including X-ray structural determinations of 3a and 4a. Voltammetric behaviors of compounds 3 and 4 were investigated, and stepwise one-electron ferrocene oxidations were observed for both compounds 4a and 4b. Spectral analysis of the monocations  + indicated that they are the Robin-Day class II mixed valent [Fc•••Fc] + species. Measurement and fitting of magnetic data (πT) of 4a between 2 and 300 K revealed a typical zero-field splitting of a S = 3/2 center with D = 77 cm -1, while those of [4a]BF 4 are consistent with the presence of S = 3/2 (Ru 2) and S = 1/2 (Fc +) centers that are weakly coupled (zJ = -0.76 cm -1).
Boyd, D.A. (Darryl A.), Cao, Z. (Zhi), Song, Y. (You), Wang, T.-W. (Tian-Wei), Fanwick, P.E. (Phillip E.), Crutchley, R, & Ren, T. (Tong). (2010). Diruthenium compounds bearing equatorial Fc-containing ligands: Synthesis and electronic structure. Inorganic Chemistry, 49(24), 11525–11531. doi:10.1021/ic101628z