Three interpenetrated copper(Ⅱ) coordination polymers based on a V-shaped ligand:Synthesis,structures,sorption and magnetic properties

Three new CuⅡ coordination polymers,[Cu2(oba)2(H2O)(DMF)].3H2O(1),[Cu4(oba)4(DMF)4].4H2O.DMF(2) and [Cu2(oba)(hmp)2](3)(H2oba = 4,4'-oxybis(benzoic acid),Hhmp = 2-pyridine methanol,DMF = N,N'-dimethylformamide) were synthesized by solvothermal reactions and characterized by single-crystal X-ray diffraction.Both complexes 1 and 2 take three-dimensional(3D) three-fold interpenetrating PtS topology with 1D channels.In complex 3,Cu4 clusters were formed by the chelating hmp ligands,and then the clusters were further linked by oba ligands to form a 3D three-fold interpenetrating dia topology network.For 2,N2 sorption shows type I isotherm with BET surface areas of 562 m2 g-1 and Langmuir surface area of 747 m2 g-1,respectively.At 77 and 87 K,the hydrogen uptakes of complex 2 are 0.89 wt% and 0.57 wt%,respectively.Magnetic investigation showed the ferromagnetic coupling between CuII ions and very weak antiferromagnetic interaction between Cu4 clusters in complex 3.

Electrochromic Two-dimensional Covalent Organic Framework with a Reversible Dark-to-transparent Switch

Electrochromic(EC)materials with a dark-to-transmissive switch have potential applications in optical communications,infrared wavelength detectors for spacecraft,and infrared camouflage coatings.Recently,Yu et al.proposed an innovative low-voltage dark-to-transparent switchable electrochrome based on a donor-acceptor two-dimensional covalent organic framework(COF)material.The compound can be facilely processed in a large-area thin film,which allows for the wide applications in smart displays,windows,and clothing.This work has been published online in Nature Communications on November 2nd,2020.

Photo Switchable Two-step Photochromism in a Series of Ln-Phosphonate(Ln=Dy,Gd,Tb,Y)Dinuclear Complexes

Exploring the discrete complexes with multi-step coloration is still a challenge in the field of electron transfer photochromic materials. Herein, we synthesized a series of dinuclear Ln-diphosphonate compounds[Ln=Dy(1);Gd(2);Tb(3);Y(4)] with a remarkably and reversibly photoactive coloration phenomenon. These compounds showed two-step coloration behavior, which were the first discrete architectures in the reported electron transfer photochromic complexes. This two-step coloration phenomenon was originated from the large distortion of H3-TPT acceptors, which in turn reduced the π-conjugation of electron acceptors and slowed the decay process of electron transfer. The photogenerated stable doublet radicals originated from electron transfer from diphosphonate donor to polypyridine acceptor in these complexes were detected by UV-Vis and electron spin resonance(ESR) spectra. Furthermore, the photogenerated radicals were estimated by direct current magnetic susceptibilities and variable temperature ESR spectra, suggesting the doublet radicals in the dinuclear structure for all the compounds. This work revealed a series of discrete phosphonate-based systems with a multi-step coloration process, providing a new pathway for designing multicolor photochromic materials with potential photoswitching or other applications.

Geminiarene: A New Macrocyclic Arene with Dual/Gemini Molecular Conformation and Guest Selectivity in the Solid State

Prof.YANG Yingwei and his coworker from Jilin University reported an entirely new kind of macrocyclic arene, namely geminiarene, featuring two different but interconvertible molecular configurations. Taking advantage of the dual/gemini confonnational feature and the unique host-guest property of geminiarene, they developed unitary and dual guest selective adsorption/separation systems, in particular toward chlorobenzene and chlorocyc 1 ohexane.

Zinc-coordination Polymers Based on a Donor-acceptor Mix-ligand System:Syntheses,Crystal Structures and Photophysical Properties

By employing an electron-rich tricarboxytriphenyl amine as donor ligand and electron-deficient 2,4,6-tris(pyridin-4-yl)-1,3,5-triazine as acceptor ligand to assemble with Zn2+ions,three new coordination polymers were successfully synthesized and characterized systematically.Three compounds with different structures were obtained by regulating the reaction solvent,and the effect of the reaction solvent on the synthesis of crystals was explored.Furthermore,the photophysical properties of the compounds were investigated.