Synthesis, structure and property of one porous Zn(salen)-based metal-metallosalen framework

Abstract

Chiral Schiff-base ligand L was synthesized through six steps in good overall yield from readily available 2-tert-butylphenol and was used to construct one chiral porous metal-metallosalen framework, [Zn5(µ3-OH)2(ZnL)4(H2O)2]·18H2O (1, L = 5′,5″-(1E, 1′E)-(1R, 2R)-cyclohexane-1,2-diylbis(azan-1-yl-1-ylidene)bis(methan-1-yl-1-ylidene)bis(3′-tert-butyl-4′-hydroxybiphenyl-4-carboxylic acid), under mild reaction conditions. 1 was characterized by IR, TGA, CD, UV, PL, single-crystal and powder X-ray crystallography. The structure of 1 displays a 3-fold interpenetrating 3D framework with 1D channel of 1.14 nm × 0.58 nm and imparts unique Zn(salen) units on the surface of the pore, in which (ZnL)2 dimer acts as multi-functionlized metalloligand. 1 is thermally robust with network decomposition temperature of 400 °C and it also exhibits strong photoluminescence in the visible region.