Crystal structure, fluorescence spectroscopy, and electrochemical property of two neodymium coordination polymers with phenoxy acids

摘要

Two nine-coordination coordination polymers of neodymium, [Nd-2(p-C8H4O4)(o-C8H4O4)(2) aEuro cent 4H(2)O] (n) (I), [Nd-2(C10H4O8)(C10H2O8) aEuro cent 2H(2)O] (n) (II), have been prepared by hydrothermal reaction of Nd(NO3)(3) aEuro cent 6H(2)O with terephthalic acid and phthalic acid, or benzenetetracarboxylic anhydride and determined by means of IR, UV, fluorescence, TG-DTA, cyclic voltammetry (CV) and X-ray single-crystal diffraction methods (CIF files CCDC nos. 1006206 (I), 979309 (II)). Yellow-green luminescence could been observed at 391 nm (lambda(ex) = 305 nm) for complex I and 370 nm (lambda(ex) = 331 nm) for the complex II. The emission of complexes I and II may be due to the pi* -> n transition, which may be assigned to the ligand-to-metal charge-transfer bands. Compared with complex II, the complex I exhibits a stronger fluorescence intensity for the different coordinated environment. Cyclic voltammetric measurement of the two compounds reveal that the compounds both have a couple of irreversible redox peak, indicating that the two polymers were both corresponded to the unusual Nd(III)/Nd(V).