The synthesis, structure, and fluorescence properties of two heptanuclear coordination compounds containing trigonal prismatic [LnCu(6)(mu-OH)(3)(Gly)(6)Im(6)](6+) cations (Ln: Eu, Sm)

摘要

Two heptanuclear trigonal prismatic polyhedra, [EuCu6(-OH)(3)(Gly)(6)Im(6)](ClO4)(6)3H(2)O and [SmCu6(-OH)(3)(Gly)(6)Im(6)](ClO4)(6)3H(2)O were synthesized through self-assembly of Eu3+(Sm3+), Cu2+, glycine, and imidazole in aqueous solution and characterized by X-ray single crystal diffraction. Both complexes crystallize in the rhombohedral R3 space group (a=b=15.8673 angstrom, c=23.4038 angstrom, V=5103.0(6)angstrom(3), Z=3) and (a=b=15.8749 angstrom, c=23.455 angstrom, V=5119.1(8)angstrom(3), Z=3). In the clusters, Sm3+ and Eu3+ ions are situated in the center of a prism formed by six copper ions and coordinate to nine oxygens with a tricapped trigonal prismatic coordination polyhedron. Six glycinato ligands and six imidazole terminal ligands (each coordinates to one Cu2+) construct the cluster. The fluorescent excitation and emission spectra showed that the complexes have strong ligand-based fluorescence.