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Single-crystal-to-single-crystal (SCSC) transformation provides a good platform for obtaining new functional coordination polymers. In this study, we demonstrate a violent and rapid structural transformation between two d10 coordination polymers (CPs). The complex 1 [Zn(3,5-thbzc) 2 (C 2 H 6 O) 2 ] transformed into the complex 2 {[Zn(3,5-thbzc) 2 (H 2 O) 2 ]·C 3 H 7 NO·2H 2 O} (where t = tbutyl, hbzc− = 2-Hydroxybenzoato) triggered by deionized water under standard temperature and pressure conditions in solid state. The transformation reaction was confirmed using single-crystal XRD, PXRD and SEM. The results showed that complex 1 adopts a bidentate chelate six-coordination mode, and complex 2 adopts a monodentate four-coordination mode. SEM clearly showed that complex 2 was in the form of random nanowire clusters, suggesting that their transformation required degradation of the entire crystal structure. UV–Vis–NIR spectra were used to calculate the band gaps of complexes 1 and 2 , which demonstrated wide-bandgap semiconductor-like materials with ∼3.2 eV band gap widths. The results of dielectric studies of complex 1 revealed that it possessed a medium dielectric constant (κ = 6.08 at 1 kHz), while complex 2 displayed an even higher dielectric constant (κ = 7.97 at 1 kHz) at room temperature. Interestingly, parent complex 1 exhibited a small ladder-like dielectric anomaly at 188 °C, while progeny complex 2 did not. This paper describes a new strategy for preparing adjustable functional dielectric materials. Through solid-state transformation triggered by deionized water, the parent bidentate six-coordination complex 1 generates the progeny monodentate four-coordination complex 2. This transformation process involves the cleavage and regeneration of coordination bonds. Complex 2 has a high dielectric constant due to the substitution of water ligands. [Display omitted] • Ligand-substituted SCSC transformation between complexes 1 and 2 was triggered by deionized water. • The transformation process involves the cleavage and regeneration of coordination bonds. • The coordination number of Zn2+ changes from six-coordination to four-coordination. • The introduction of H 2 O ligands can significantly improve the dielectric constants of Zn-CPs. • Complex 1 shows a ladder-like dielectric anomaly at 188 °C. [ABSTRACT FROM AUTHOR]

Metal-organic frameworks (MOFs) have been widely used in filed of electrochemistry. Compared with traditional inorganic porous materials, the polyvalent pyridinecarboxylic acid ligands have many advantages which contains more active sites, flexible coordination mode, adjustable structure. Therefore, it becomes good choice for constructing MOFs materials with excellent performance. In this paper, a novel MOF was synthesized by pyridine polycarboxylic acid ligand and CoCl 2 ·6H 2 O using solvothermal method. The physicochemical properties were characterized by FT-IR, powder diffraction and thermogravimetry. Single crystal X-ray diffraction reveal that MOF-1 crystallizes in monoclinic system with P 2 1 / C space group. The central Co2+ ions have a dual core structure with 5 and 6 coordination, respectively. The carboxyl groups show two kinds of coordination modes μ 2 : η1: η1 and μ 2 : η1: η2, and the pyridine N atoms also coordinate to form a three-dimensional network structure. Electrochemical experiments show that MOF-1 has a lower overpotential (339.4 mV) and Tafel slope (65.3 mV·dec−1) with higher ECSA and better OER kinetics. A large number of exposed active sites indicate that the MOF has higher potential as catalyst for oxygen evolution reaction. [Display omitted] • A Co-MOFs based on pyridine polycarboxylic acid ligand were prepared by a simple hydrothermal method. • Electrochemical test show that the MOFs has a lower overpotential and Tafel slope with higher ECSA and better OER kinetics. • MOFs exhibit a porous three-dimensional network structure. [ABSTRACT FROM AUTHOR]

Urease may rapidly hydrolyze urea, causing a significant amount of ammonia to be released and decreasing the efficacy of urea fertilizers. However, urease inhibitors (UIs) can inhibit the interaction between urease and urea so that ammonium nitrogen can be absorbed by crops for a long time. In this paper, we developed and fabricated two Cu-based coordination polymers (Cu-CPs) to function as UIs by combining two aromatic carboxylic acids and a bis-pyridine-bis-amide ligand, which demonstrate outstanding urease inhibitory efficacy. Cu-CP-1 exhibits a pronounced inhibitory effect on the inhibitory activity of jack bean urease while the semi-inhibitory concentration (IC 50) value was 0.74 ± 0.01 μM, whereas the IC 50 value of Cu-CP-2 was 4.77 ± 0.51 μM. Furthermore, inhibitory activity against urease, kinetic, molecular docking, and comparisons of the title Cu-CPs and other complex-based materials have been comprehensively investigated. More importantly, the oxygen atoms of μ 2 -OH and –COO play important roles in urease inhibition activity. The structure–function relationship were further discussed which indicates that Cu-CPs can be used as a kind of UIs. By using different O-donor second auxiliary ligands, we have designed and synthesized two Cu-based CPs to operate as urease inhibitors which show excellent urease inhibitory activity. [Display omitted] • The development of UIs has been a matter of great concern to researchers. • Two Cu-CPs have been synthesized by using diverse O-donor ligands. • The Cu-CPs are served as UIs and show excellent urease inhibitory activity. • Inhibitory activity, kinetic, molecular docking of the Cu-CPs have been studied. [ABSTRACT FROM AUTHOR]

To search for more high-performance crystalline proton conducting materials and to accelerate the related research progress, in this paper, a one-dimensional coordination polymer (CP), [Co(BBOT) 2 (H 2 O) 3 ·2H 2 O] n (1) (H 2 BBOT = N-benzoyl-N′-(4-benzoxy)thiourea) was firstly prepared by solvent volatilization approach. Subsequently, the thermal, H 2 O and chemical stabilities of the CP were tested and its high structural stability was confirmed. Furthermore, in 1 , a stable solid three-dimensional framework can be constructed by intermolecular H-bonds and stacking interactions between phenyl units. Then, utilizing the AC impedance determination, the dependence of the proton conductivity of this CP on temperature and humidity in the water vapor environment was explored and the positive correlation was verified. Excitingly, the optimized proton conductivity of this compound under specific test conditions (100 °C/98 % relative humidity) can be as high as 10−4 S/cm, being in the forefront of similar crystalline solid materials. Finally, according to the value of activation energy and the characteristics of crystal structure, we speculate on the proton conduction mechanism. Proton conductivity of a CP under variable humidity and temperatures was explored. Its highest proton conductivity can attain up to 10−4 S/cm, and its proton-conduction mechanism was speculated. [Display omitted] • One carboxylate-based Co(II) coordination polymer was prepared. • Its structure was characterized by single-crystal X-ray diffraction. • Its water-assisted proton conduction was explored. • The proton-conducting mechanism was speculated. [ABSTRACT FROM AUTHOR]