Department of Chemistry, Keio University
○Takashiro Akitsu Yasuaki Einaga
Recently, we have discovered the first photo-induced magnetization phenomenon of 3d-4f cyanide-bridged bimetallic assemblies, Ln(DMF)4(H2O)3M(CN)6.H2O (Ln = Nd; M=Fe, Co) . In contrast to conventional photo-induced electron transfer for cyanide-bridged 3d-3d transition metal complexes, the photo-induced magnetization for 3d-4f complexes was suggested to be due to structural distortion of cyanide-bridge ligands as well as lattice strain of the crystals. In order to elucidate the relationship between molecular or crystal structures and their electronic properties, we have developed metal-substituted complexes exhibiting various dimensionality such as bimetallic complexes, one-dimensional chains, and two-dimensional sheets systematically. In the present paper, we will report on new one-dimensional chain structures, magnetism, and IR, electronic, and XPS spectroscopic properties of, Ln(DMF)4(H2O)2Cr(CN)6.H2O (Ln = Tb, Dy, Ho, and Er) complexes.
Because of lanthanoid contraction, four complexes are isostructural in P21/a showing gradual differences in both cell parameters and Ln-N bond lengths or Ln-N-C bond angles. Only Dy and Er complexes could be solved as P21/c, though structural similarity between P21/c and P21/a complexes was proved by powder pattern simulation. The detailed electronic properties in the solid state will be presented later.
 G. Li, T. Akitsu, O. Sato, and Y. Einaga, J. Am. Chem. Soc., 125, 12396 (2003).