Selective pyridine recognition by an imidazole dicarboxylate-based 3D cadmium(ii) MOF

Abstract

One newly prepared 3D polymer (1) composed of left- and right-handed helices containing [Cd8(p-ClPhHIDC)12(4,4′-bipy)6] cages shows selective pyridine recognition, with a visual colour change from pearl to pink under ultraviolet irradiation.

Four new metal–organic frameworks based on bi-, tetra-, penta-, and hexa-nuclear clusters derived from 5-(phenyldiazenyl)isophthalic acid: syntheses, structures and properties

“…As shown in Fig. 1a, 50 the dinuclear copper paddle-wheel SBU is bound with four carboxylates from four different PDIA 2ligands and two terminal coordinated DMA molecules (Cu-O = 1.951-2.161 Å). As shown in Fig.…”

“…Temperature 45 dependent magnetic susceptibility data were carried out by the use of a Quantum-Design MPMS-XL SQUID magnetometer over the temperature range of 2-300 K under an applied field of 1 kOe. 1 H NMR spectra were recorded on a Bruker AV 400 spectrometer with Me 4 Si as the internal standard in deuterated solvents CDCl 3 50 and DMSO-d 6 at 298 K. The fluorescence measurements for JUC-128 were recorded on a Fluoromax-4 Spectrofluorometer in the solid state at room temperature.…”

“…A single-crystal X-ray diffraction analysis reveals 50 that JUC-128 crystallizes in the trigonal R-3c space group and shows a 3D coordination framework. In the asymmetric unit, there is one Zn1, a half Zn2, one third Zn3, one Zn4, one Zn5, three PDIA 2ligands, one third µ 4 -O atom (O14), one µ 3 -OH group (O13) and one terminal coordinated DMA molecule (Fig.…”

“…In mode 1, each PDIA 2ligand links four Co(II) centers through the µ 4 -η 2 :η 2 coordination mode, while µ 6 -η 3 :η 3 coordination mode in mode 2. Each hexanuclear SBU [Co 6 (µ 3 -OH) 2 (COO) 10 ] is linked with eight diverse ligands to form a 2D layer, which is 50 further packed together by π-π stacking interactions between arene cores of two independent PDIA 2-(3.627 Å) to form a 3D supramolecular architecture (Fig. 4d).…”

“…[30][31][32][33][34][35][36][37] Yaghi 45 et al reported elongated organic linkers with the same metalcontaining secondary building units (SBUs) to tune the size of pores in isomeric frameworks. 38 However, to the best of our knowledge, reports are still rare on the construction of MOFs with a rigid ligand, which contains large aromatic rings without 50 any coordination nodes, not only because the aromatic ring can't join the work to connect to metals, but also the overcrowded space. 39 On the other hand, azobenzene functionalized ligand have been prepared to synthesize dynamic and photo-responsive MOFs.…”