Synthesis and characterization of 2-(2-benzimidazolyl)-6-methylpyridine Cu (Ⅰ) Fe (Ⅱ) heterodinuclear complex

A Cu (Ⅰ) Fe (Ⅱ) heterometallic dinuclear complex Cu (Hbmp)(dppf)(ClO₄) (1) was synthesized by using 1, 1′-bis (diphenylphosphino) ferrocene (dppf), 2-(2-benzimidazolyl)-6-methyl pyridine (Hbmp) and Cu (CH₃CN)₄(ClO₄) as raw materials. As revealed by single-crystal X-ray diffraction, compound 1 is a Cu (Ⅰ) Fe (Ⅱ) heterodinuclear complex, in which the Cu (Ⅰ) ion adopts a four-coordinate mode and connects with two N and two P atoms to form a distorted tetrahedral configuration, while the Fe (Ⅱ) ion is sandwiched between two cyclopentadienyl moieties to generate a staggered sandwich biscuit geometry. Complex 1 has a weak low-energy broad absorption in the 355~460 nm region, which is assigned to metal-to-ligand charge-transfer (Cu (Ⅰ)→Hbmp, MLCT) transition, mixed with some ligand-to-ligand charge-transfer (dppf→Hbmp, LLCT) transition.