Synthesis and photoluminescence of Zinc(II) complexes with tetrafluoroterephthalic acid (H2L). Crystal structure of coordination polymer [Zn(H2O)4(L) · 4H2O]n

Complexes Zn(H 2 O) 4 (L) ( I ) and Zn(H 2 O)(L) ( II ) (H 2 L = p -HOOCC 6 F 4 COOH) are synthesized. Single crystals of compound [Zn(H 2 O) 4 (L) · 4H 2 O] n ( III ) are grown. According to the X-ray diffraction data, the crystal structure of compound III is built of zigzag chains of coordination polymer Zn(H 2 O) 4 (L) and molecules of water of crystallization. The chain contains ions Zn 2+ , whose octahedral coordination sphere includes the O atoms of four water molecules and two O atoms of the deprotonated carboxyl groups. The chains in structure III are joined by a system of hydrogen bonds of coordinated water molecules and molecules of water of crystallization. The photoluminescence spectrum of H 2 L exhibits the band with λ max = 368 nm. The spectra of compounds III , I , and II contain bands at 322, 340, and 353 nm, respectively.