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• The pyridine polymers with cationic skeleton were obtained utilizing conjugation ring. • The cationic framework of pyridine polymers endows them with Au(III) selectivity. • The single point contact improved the pyridine polymer adsorption capacity for gold. • The cationic pyridine polymers perform well in practical solutions with significantly varying ionic concentrations. Recovering gold from rich waste printed circuit boards (WPCBs) resource are of great significance to gold development and utilization. In this paper, cationic pyridine polymers with different configurations were designed and synthesised for highly selective and efficient recovery of gold from a WPCB leaching solution. The structures and performances of the cationic pyridine polymers were analysed using a 4–aminopyridine polychloromethylstyrene (4–AP/PCMS). The results indicate that the 4–AP/PCMS performed well in an acidic environment, including in the 5 % aqua regia solution. Gold adsorption on the 4–AP/PCMS followed pseudo–second–order kinetics and Langmuir isotherm models, suggesting that chemisorption occurred via a single–layer mechanism with a maximum loading capacity of 437.68 mg/g. Further, Au(III) adsorption on the 4–AP/PCMS involved electrostatic interactions and reduction between pyridine and AuCl 4 −. After five adsorption–desorption cycles, the adsorption rate remained above 99 %, whereas in actual leaching solutions it reached 92.24 %. All five pyridine polymers demonstrated outstanding Au(III) selectivity over binary and multicomponent solutions containing Cu(II), Ni(II), Co(II), Zn(II), Fe(III), Cd(II), and Mg(II), benefitting from the cationic pyridine skeleton. Contact patterns between the cationic pyridine polymers and AuCl 4 − considerably affected the gold loading capacity, and a single–point contact was found to be favourable for gold adsorption. These results indicated that cationic pyridine polymers are promising for recovering gold from WPCB leaching solutions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Crowding-out strategy is proposed to remove structural H 2 O molecules in E-MOFs. • Double-ligand E-MOFs were synthesized by adjusting pH at room temperature/pressure. • The properties of NTO based E-MOFs are greatly improved after modification. • Double-ligand E-MOFs have excellent catalysis for the thermal decomposition of AP. Based on the combination of coordination chemistry and the noncovalent interactions, the crowding-out concept is put forward to fundamentally solve the problem that the structural H 2 O in E-MOFs results in a decreased stability, density and heats of detonation. In this paper, "filling" the 4,4′-azobis(1,2,4-triazole) (ATRZ) molecules into the structure of NTO (3-nitro-1,2,4-triazol-5-one) E-MOFs, the coordination and crystal water molecules were successfully extruded to gain anhydrous [Cu(NTO) 2 (ATRZ)] ( a ) / [Zn(NTO) 2 (ATRZ)] ( c ) and hypohydrous [Co(NTO) 2 (ATRZ)(H 2 O) 2 ]·ATRZ ( b ) by adjusting pH at room temperature and pressure, which is friendly for energetic materials. With the addition of ATRZ (high HOF) and the departure of water, the Δ f H m θ of them are becoming higher. The heat of detonation is increased by 1.33, 2.39 and 0.74 times respectively and the calculated detonation velocity of three compounds is enhanced by about 1000 m s−1 contrasted to the corresponding hydrates. The removal of water molecules did not result in a high sensitivity. More importantly, as potential catalysts for AP-based solid propellants, a and c still showed excellent catalysis for the thermal decomposition of AP (ammonium perchlorate) after modification. In this study, it took a whole new idea to radically solve the difficulties in the area of E-MOFs by a simple and original way, and this is a significant innovation for the safety of energetic material. [ABSTRACT FROM AUTHOR]

In this paper, the precursors of the coordination polymer Ce(1,3,5-BTC)(H 2 O) 6 with different morphologies have been successfully prepared via a facile and rapid method, and then the CuO/CeO 2 catalysts were obtained by impregnation method to support copper species. The catalysts were characterized by scanning electron microscopy, scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, ultraviolet Raman spectrscopy, N 2 adsorption-desorption, H 2 programmed temperature reduction and X-ray photoelectron spectroscopy, respectively. The results showed that U–CuCeO catalyst has stronger CuO dispersion and higher oxygen vacancy concentration on the surface. The high specific surface area of U–CuCeO catalyst facilitates the highly dispersed CuO species and enhances the interaction between copper and cerium, and improves the catalytic performance compared with the other catalysts. For U–CuCeO catalyst, the CO conversion reached 100% at 120 °C. It also exihibited the broadest complete reaction temperature window. [Display omitted] • The precursors of the coordination polymer Ce(1,3,5-BTC)(H 2 O) 6 with different morphologies were prepared. • Three different morphologies of CuO/CeO 2 catalysts were evaluated. • The reason for the high activity of the Urchin-like catalyst was analyzed in detail. [ABSTRACT FROM AUTHOR]

• One-dimensional chloro-bridged coordination polymer of Cu(II) ion was prepared. • Cu(II)-based polymer displayed a supramolecular structure via hydrogen bonds. • The Cu(II) polymer displays ferromagnetic behavior within the 1-D chain. • The copper(II) species cleaves sc DNA through oxidative pathways. A new coordination polymer, [Cu(pmaeOH)Cl 2 ] n , based on the copper(II) ion and 2-(2-pyridine-2-ylmethylamino)ethanol (pmaeOH) ligand was obtained from a methanol solution. The coordination polymer was characterized by elemental analysis, infrared spectroscopy, X-ray single-crystal diffraction, magnetic susceptibility measurements, and DNA cleavage effect. The crystal structure of the polymer consisted of a one-dimensional (1-D) chain with each copper(II) atom six-coordinated (by three nitrogen atoms and three chlorine atoms) in a severely distorted octahedral geometry. The polymer exhibited ferromagnetic behavior within the 1-D chain (J = 6.35 cm−1) through the long bond distances of copper(II) and chloride ions. The copper(II) complex cleaves sc DNA through oxidative pathways, where the reactive oxygen species (ROS) involved in DNA cleavage are the superoxide radical (⋅O 2 –), singlet oxygen (1O 2), and hydrogen peroxide (H 2 O 2). This paper reports the new synthesis of a ferromagnetically coupled polymer bridged with a chloride ion and its DNA cleavage effect for molecular memory devices and DNA repair applications. A new coordination polymer, [Cu(pmaeOH)Cl 2 ] n , displays a one-dimensional zigzag chain structure, ferromagnetic behavior within the 1-D chains as well as cleavage of sc DNA through oxidative pathways. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper reports the syntheses and structural characterization of three new Cu(II) coordination polymers, namely [Cu(BAEE)(N 3 ) 2 ] ∝ ( 1 ), [Cu(BAEE)(NCO) 2 ] ∝ ( 2 ) and [Cu(BAEE)(NCS) 2 ] ∝ ( 3 ), where BAEE is 1,2-bis(2-aminoethoxy)ethane. Compound 1 is a one-dimensional (1D) single-stranded normal helical structure, while compounds 2 and 3 are extraordinary single-stranded meso-helical polymers. The influence of pseudohalides in these systems is observed as the azide ions are cis coordinated in 1 and the thiocyanate ions are trans coordinated in 3 , while alternate metal centers are either cis or trans coordinated with cyanate ions in 2 . These geometrical preferences play a crucial role in the diverse helicity in these chain structures, where the cis arrangement (in 1 ) favors a uniform helicity in the structure and the trans arrangement (in 2 and 3 ) of the pseudohalide ligands around the copper(II) center brings meso-helicity in the chains. The energetic difference of the cis / trans isomers and the formation energies of the different assemblies using DFT calculations suggest that the different H-bond acceptor ability of the thiocyanate ion determines the different architecture observed in 3 . Our results highlight how the geometrical preferences of the pseudohalides around the copper(II) center influence the helical diversity in these systems and thereby provide a clue toward the development of uncommon coordination polymers with amazing meso-helical character. [ABSTRACT FROM AUTHOR]

• The ligand forms stable complexes with transition metal ions. • Speciation of its complexes, featuring different stoichiometries, is fully understood. • It is suitable for non-covalent functionalization of carbon surfaces (CNTs, graphene) • It is promising for the preparation of heterogeneous Pd(II)-based catalysts. The new ligand H 2 L, constituted by a tetraethylenepentamine functionalized with terminal 6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidine groups, has been synthesized with the ultimate goal of preparing Pd2+-containing heterogeneous single metal ion catalysts based on multi-walled carbon nanotubes (MWCNT-L-Pd) and graphene (G-L-Pd) for catalytic applications. In this paper, we report the synthesis of the ligand and a preliminary characterization of its coordination properties performed by using Zn2+ and Cu2+ as test cations. The high stability constants, determined for the complexes with these metal ions in aqueous solution, the fast kinetic of the complexation reactions as well as the calculated structural features of the complexes are promising prerequisites supporting a successive study on the application of MWCNT-L-Pd and G-L-Pd catalysts. [ABSTRACT FROM AUTHOR]