J. Iran. Chem. Soc., Vol. 7, No. 4 December 2010, pp.825-833.

Current location: JICS Archive > Vol. 7 > No. 4 > Articles : 5

Synthesis, Crystal Structure, Electrochemical and Fluorescence Studies of a Novel Zn(II)-Fluorophore, 1,10-Phenanthroline-5,6-dione (Phen-dione)

Macrocyclic complex, Schiff base, Cadmium(II),  Pendant arm, Ab initio A.R. Rezvania,*, H. Saravania and H. Hadadzadehb

aDepartment of Chemistry, University of Sistan and Baluchestan, P. O. Box 98135-674, Zahedan, Iran
bDepartment of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran

The crystal structure of 1,10-phenanthroline-5,6-dione ligand with Zn(II), tris(1,10-phenanthroline-5,6-dione)zinc(II) hexafluorophosphate, [Zn(phen-dione)3](PF6)2, is reported. The complex was characterized by elemental analysis, IR, 1H NMR, electronic absorption spectroscopies, cyclic voltammetry and X-ray crystallography. Yellow crystals of [Zn(phen-dione)3](PF6)2 were formed by ether diffusion into an acetonitrile solution of the complex. The title complex crystallized in monoclinic crystal system (Z = 2) with space groups of P21, a = 12.0299(15) Å, b = 14.5306(19)Å, c = 13.1879(17)Å, β = 94.058(2)�° and V = 2299.5(5) Å3. The structure was refined by using 10048 independent reflections, with I > 2s(I) to an R factor of 0.0490. Single-crystal structure showed that the coordination geometry around the Zn(II) was a distorted octahedron. The complex showed an intense fluorescence band at visible region (690 nm) in CH3CN with an excitation wavelength of 310 nm at 25.0 �±  0.1 �°C.         Cyclic voltammogram of the title complex showed two quasi-reversible reduction couples at negative potential, which were assigned to the consecutive reduction of phen-dione ligand to phen-semiquinonate and phen-diolate respectively by analogy to other phen-dione complexes at scan rate 200 mV s-1.

Keywords: Zn(II) complex, 1,10-Phenanthroline-5,6-dione, Zn(II)-Fluorophore, Phen-semiquinonate, Fluorescence

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