A new family of binuclear lanthanide
compounds of general formula [Ln(2,4-DClBA)3phen]2 (Ln(III) = Nd (1), Sm (2), Dy (3), Yb (4); 2,4-DClBA = 2,4-dichlorobenzoate; phen =
1,10-phenanthroline) have been synthesized and characterized by elemental
analysis, molar conductance, infrared spectroscopy, ultraviolet spectra,
thermogravimetric analysis, and single-crystal X-ray diffraction.
On the basis of X-ray crystallography, compounds 2–4 belong to the triclinic crystal system, PI̅ space group. In compound 2, the Sm3+ ion adopted a distorted monocapped square-antiprism coordination
geometry. Compounds 3 and 4 are isomorphous
whose central ions (Dy3+ and Yb3+) formed a
distorted square-antiprism geometry. The heat capacities of compounds 1–4 are measured using DSC technology
and fitted to a polynomial equation by the least-squares method. The
smoothed molar heat capacities and thermodynamic function data of
compounds 1–4 relative to the reference
temperature 298.15 K are then calculated. Meanwhile, these compounds
exhibit in good antifungal activity against C. albicans, good antibacterial activity against S. aureus, and better antibacterial activity against E. coli. The fluorescence spectra of the samarium and dysprosium compounds
behave as characteristic transitions of Sm(III) and Dy(III) ions.