Crystal structures and solid-state CPMAS 13C NMR correlations in luminescent zinc(II) and cadmium(II) mixed-ligand coordination polymers constructed from 1,2-bis(1,2,4-triazol-4-yl)ethane and benzenedicarboxylate

Abstract

The hydrothermal reaction of M(NO(3))(2).4H(2)O (M = Zn and Cd) with benzene-1,4-dicarboxylic acid (H(2)bdc) or benzene-1,3-dicarboxylic acid (H(2)ip) and 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) produced the mixed-ligand coordination polymers (MOFs) {[Zn(2)(micro(2)-bdc)(2)(micro(4)-btre)]} (), {[Cd(2)(micro(4)-bdc)(micro(4)-btre)(2)](NO(3))(2).H(2)O} and {[Zn(2)(micro(3)-ip)(2)(micro(2)-btre)(H(2)O)(2)].2H(2)O} (). The compounds, characterized by single-crystal X-ray diffraction, X-ray powder diffraction, solid-state cross-polarization (CP) magic-angle-spinning (MAS) (13)C NMR and thermoanalysis, feature 3D metal-organic frameworks for and and 2D double layers which are connected through hydrogen bonds from the aqua ligands for 3. The CPMAS (13)C NMR spectra picture the symmetry-independent (unique) C atoms and the bdc/ip-to-btre ligand ratio in agreement with the crystal structures. The zinc and cadmium coordination polymers show a strong bluish fluorescence upon excitation with UV light (the free btre ligand is non-luminescent).

A Cadmium Anionic 1-D Coordination Polymer {[Cd(H2O)6][Cd2(atr)2(μ2-btc)2(H2O)4] 2H2O}n within a 3-D Supramolecular Charge-Assisted Hydrogen-Bonded and π-Stacking Network

“…The combination of neutral nitrogen donor ligands with anionic carboxylate ligands are frequent choices for the synthesis of mixed-ligand networks [22]. The linker 1,2-bis(1,2,4-triazol-4-yl)ethane (abbreviated as btre, Scheme 1) has recently been intensely studied in mixed-linker MOFs [19][20][21][22][23][24] and single-linker networks [25]. Herein, we report an attempt to construct a mixed-linker network with the 4,4 1 -bis(1,2,4-triazol-4-yl) (btr) ligand which was not hydrothermally stable under the synthesis conditions of 125˝C in water, so that the hydrolysis product 4-amino-1,2,4-triazole (atr) was incorporated instead (Scheme 1).…”

“…Coordination polymers based on mixed-linkers allow for a fine-tuning of MOF properties and can show additional characteristics such as crystal-to-crystal transformations [19], short and long-range magnetic ordering [20], luminescence [21], etc. [22].…”

Synthesis, Crystal Structure and Characterization of Cu(II) and Cd(II) Coordination Compounds Based on Ligand 2-(3-(Pyridin-2-yl)-1H-pyrazol-1-yl)acetic Acid

“…The other reason is that these complexes have many potential applications in, for example, magnetism, gas separation, optoelectronics and biomimetic materials. [7][8][9][10][11] Studies in this field have been focused on the design and preparations of coordination complexes, as well as structure-property relationships. Among the reported organic ligands, carboxylate compounds and N-donor compounds are the most efficient families and play dominant roles in fabrication of coordination complexes.…”

Synthesis, Structures and Properties of Two Metal-organic Frameworks Derived from 3-Nitro-1,2-benzenedicarboxylic Acid

“…Utilizing hydrothermal technique, (2) have been obtained. In addition, fluorescent properties, thermal decomposition process and powder X-ray diffraction of compounds 1 and 2 were studied.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] Studies in this field have been focused on the design and preparation, as well as the structure-property relationships. Although big progress has been achieved, 16 it is still a great challenge to predict the exact structures and composition of the assembly products built by coordination bonds and/or hydrogen bonds in crystal engineering.…”