Synthesis, structure and M?ssbauer characterization of polymeric iron(II) complexes with bidentate thiourea ligands

摘要

Complexes of FeCl_2 with the known bis(3-methyl-2-thione- imidazolyl)methane (L~1) and the new bis(3-tert-butyl-2-thione- imidazolyl)methane (L~2) are reported. For both [L ~1FeCl_2]_n (3) and [L~2FeCl _2]_n (4) X-ray crystallography reveals that 1D-polymeric chain structures are present in the solid state, with the two mercaptoimidazolyl units of L~1 and L~2 coordinating to different metal ions. Complexes 3 and 4 are further characterized by M?ssbauer spectroscopy and SQUID magnetometry. NMR spectroscopy suggests that the complexes largely dissociate in polar solvents. X-ray structures of L~2 and its precursor bis(imidazolium) salt are also reported.