STUDIES ON A NEW TYPE OF TERBIUM COMPLEX WITH SULPHONATED CATECHOLATE - THE MOLECULAR STRUCTURE AND FLUORESCENCE PROPERTIES [TB-2(C6H3S2O8)(2)CENTER-DOT-6DMF](N)

摘要

Reaction of sulphonated catecholate Na2C6H4S2O8 (Tiron) and terbium perchlorate with a 3:2 mole ratio in hot water resulted in the precipitation of crystalline Tb-2(C(6)H(3)S2O(8))2 . 5H(2)O (A) which was recrystallized in water-DMF mixed solvent to obtain the title complex Tb-2(C6H3S2O8)(2) . 6DMF (B). The X-ray crystal structure determination of B indicates that Tiron and terbium ion form a chain polymer with a 1 : 1 mole ratio. The unique structural unit is a dimer in which two terbium ions are bridged by one oxygen atom from a deprotonated hydroxyl group of Tiron. The distance between terbium ions is 3.385 Angstrom. The terbium ion is eight-coordinated dodecahedral. The elemental analysis data and thermographic data show that compound B loses one DMF molecule in air to become Tb-2(C6H3S2O(8))2 . 5DMF (B'). The fluorescence spectra of A and B' have been studied. Both A and B' have the same maximum excitation wavelength (318 nm) at which the emission fluorescence intensity of B' is 2.5 times that of A at 543 nm. The thermogravimetric analysis and IR spectra of A and B' have been studied. [References: 6]