Hydrothermal synthesis, crystal structure and luminescence of four novel metal–organic frameworks

Using the principle of crystal engineering, four novel metal–organic coordination polymers, {[Cd1(nic)2(H2O)]2[Cd2(nic)2(H2O)2]}n (1), [Cd2(fma)2(phen)2]n (2), [Cd(fma)(bipy)(H2O)]n (3) and [Zn(mal)(bipy)·3H2O]n (4) (nic=nicotinate, fma=fumarate, mal=malate, phen=phenanthroline, bipy=2,2′-bipyridine) have been synthesized by hydrothermal reaction of M(CH3COO)2·2H2O (M=Zn, Cd) with nicotinic acid, fumaric acid and cooperative L (L=phen, bipy), respectively. X-ray analysis reveals that complex 1 possesses an unprecedented two-dimensional topology structure constructed from three-ply-like layers, complex 2 is an infinite 2D undulating network, complex 3 is a 1D zigzag chain and complex 4 belongs to a 1D chain. The results indicate a transformation of fumarate into malate during the course of hydrothermal treatment of complex 4. The photophysical properties have been investigated with luminescent excitation and emission spectra.

Graphical abstractUsing the principle of crystal engineering, four novel metal-organic coordination polymers, {[Cd1(nic)2(H2O)]2[Cd2(nic)2(H2O)2]}n, [Cd2(fma)2(phen)2]n, [Cd(fma)(bipy)(H2O)]n and [Zn(mal)(bipy)·3H2O]n have been synthesized by hydrothermal method. X-ray analysis reveals that complex 1 possesses an unprecedented two-dimensional topology structure constructed from three-ply-like layers, complex 2 is an infinite 2D undulating network, complexes 3 and 4 belong to a 1D chain. The results indicate a transformation of fumarate into malate during the course of hydrothermal treatment of complex 4.Figure optionsDownload full-size imageDownload as PowerPoint slide