Central-metal exchange, improved catalytic activity, photoluminescence properties of a new family of d¹⁰ coordination polymers based on the 5,5′-(1H-2,3,5-triazole-1,4-diyl)diisophthalic acid ligand

Abstract

The rigid and planar tetracarboxylic acid 5,5'-(1H-2,3,5-triazole-1,4-diyl)diisophthalic acid (H4L), incorporating a triazole group, has been used with no or different pyridine-based linkers to construct a family of d(10) coordination polymers, namely, {[H2N(CH3)2]3[Cd3(L)2(HCOO)]}n (), {[Cd2(L)(py)6]·H2O}n (), {[H2N(CH3)2] [Cd2(L)(HCOO)(H2O)4]}n (), {[Zn(H2L)]·H2O}n (), and {[Zn(H2L)(4,4'-bipy)0.5]·C2H5OH·H2O}n () (py = pyridine, 4,4'-bipy = 4,4'-bipyridine). constructs a 3D porous network containing two kinds of channels: one is filled with coordinated HCOO(-) anions, and the other with [H2N(CH3)2](+) cations. The framework of can be described as a rare (5,6,7)-connected net with the Schläfli symbol of (4(12)·5·6(2))(4(5)·5(3)·6(2))2(4(8)·5(3)·6(8)·8(2))2. The Cd(ii) ions in are connected through the carboxylate ligands to form a 2D layer, with aperture dimensions of ∼15.1 Å × 16.2 Å. The network of features a 3D (3,4)-connected (6·8·10)2(6·8(3)·10(2)) topology. A 3D network with the (4(2)·6·8(3)) topology of possesses an open 1D channel with the free volume of 29.2%. is a 2D layer structure with the (4(2)·6(3)·8)(4(2)·6) topology. The fluorescence lifetime τ values of are on the nanosecond timescale at room temperature. In particular, central-metal exchange in leads to a series of isostructural M(ii)-Cd frameworks [M = Cu (), Co (), Ni ()] showing improved catalytic activity for the synthesis of 1,4,5,6-tetrahydropyrimidine derivatives. Based on this, a plausible mechanism for the catalytic reaction has been proposed and the reactivity-structure relationship has been further clarified.

A microporous metal–organic framework with open metal sites for selective sensing Fe3+, CrO42- and nitrobenzene

“…Recently, Hou and his co-workers have prepared a new MOF of {[Zn(H 2 L)]·H 2 O} n (1), it has been constructed by a rigid and planar tetracarboxylic acid 5,5'-(1H-2,3,5-triazole-1,4-diyl)diisophthalic acid (H 4 L) [14]. Moreover, 1 has five potential sensing sites and its sensing properties were not explored at all.…”

Influence of a Substituted Methyl on the Photoresponsive Third-Order Nonlinear-Optical Properties Based on Azobenzene Metal Complexes

“…The distances of the Zn−O bond are from 1.9592(26) to 2.039(2) Å, and the O−Zn−O bond angles vary from 81.67 (10)°to 141.72(10)°, which are similar to those of the reported Zn complexes. 35,36 In this structure, carboxylate groups respectively connect two Zn1 and two Zn2 to form the binuclear [Zn 2 (CO 2 ) 2 ] unit. The two [Zn 2 (CO 2 ) 2 ] units become a 1D chain structure by extending infinitely (Figure 1c).…”

High Proton Conductivity in Nafion/Ni-MOF Composite Membranes Promoted by Ligand Exchange under Ambient Conditions

“…The exploration of excellent MOF conductors is an ongoing yet formidable challenge. Inspired by our previous work on single-crystal-to-single-crystal skeleton exchange, we were attracted to the report that central metal exchange enhances the proton conduction performance of exchange products. − There are differences in the coordination ability between different central metals and ligands. Driven by strong coordination, original metal ions dissociate from the ligands and enter the solution, while new metal ions enter the crystal lattices from the solution and coordinate with the ligands.…”