Synthesis, Structure and Photoluminescence of One Zinc-based Metal-metallosalen Framework

Dicarboxyl-functionalized salen ligand 1,2-phenylendiamine-N,N'-bis(3-tert-butyl-5-(carboxyl)-salicylide-ene (H4L) was synthesized in good yield from 3-tert-butyl-5-formyl-4-hydroxybenzoic acid and used to construct a 2D zinc complex, [(ZnL)Zn-3/2(BDC)(1/2)(DMSO)(2)]center dot 3DMSO (1, BDC = 1,4-benzenedicarboxylate), under mild reaction conditions. 1 was characterized by IR, microanalysis, TGA and single-crystal X-ray crystallography. It crystallizes in triclinic space group P (1) over bar with a = 11.3860(4), b = 13.2636(5), c = 17.5503(7) angstrom, alpha = 92.2240(10), beta = 94.5070(10), gamma 96.0580(10)degrees, V = 2624.52(17) angstrom(3), Z = 2, M-r = 1143.62, D-c = 1.448 g/cm(3), F(000) = 1186, mu = 1.395 mm(-1), GOOF = 0.993, the final R = 0.0380 and wR= 0.1280 for 21752 observed reflections with I > 2 sigma(I). The 2D coordination polymer 1 is further assembled into a 3D supramolecular network structure via pi(...)pi interactions between the aromatic rings of the ligands in adjacent layers. Thermal gravimetric analysis demonstrates that 1 is a thermally robust structure with network decomposition temperatures of 420 degrees C and it also exhibits strong photoluminescence in the visible region.