Syntheses, structures and luminescent properties of heterodinuclear Cd-Ln coordination compounds

Three novel heterodinuclear d-f coordination compounds [ LnCd (C-8 H-7 O-3), (phen) (H2O)] (Ln = Dy 1, Pr 2, Gd 3; C-8 H-7 O-3 =4-methoxy-benzoate; phen = 1, 10-phenanthroline) were synthesized by the hydrothermal method, and their structures were determined by single-crystal X-ray diffraction. They are isomorphous. In each molecule the Cd2+ ion is five -coordinated and the Ln(3+) ion is eight-coordinated, which are bridged by three 4-methoxybenzoates. In addition,. two neighboring molecules are connected with hydrogen bonds, forming dimers in their crystal. The IR, UV-Vis-NIR absorption, the excitation and emission spectra of the three complexes were determined at room temperature. The associations between the UV-Vis-NIR absorption spectra and the emission spectra of the complexes were analyzed and the influences of the d-block component on the luminescence of Ln(3+) were discussed.