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Two two‐dimensional supramolecular Nickel(II) and Cobalt(III) complexes, [Ni(L2)2]·2CH3OH (1) and [2Co(L2)2] (2) (HL2 = 1‐(2‐{[(E)‐3‐bromo‐5‐chloro‐2‐hydroxybenzylidene]amino}phenyl)ethanone oxime), were synthesized via complexation of salts acetate with HL1 (2‐(3‐bromo‐5‐chloro‐2‐hydroxyphenyl)‐4‐methyl‐1,2‐dihydroquinazoline 3‐oxide, H is the deprotonatable hydrogen). During the reaction, the C–N bond in HL1 is converted into the C=N–OH group in HL2. The spectroscopic data of both complexes were compared with the ligand HL1. HL1 and both complexes were determined by single‐crystal X‐ray crystallography. The differently geometric features of the obtained complexes 1 and 2 are observed. In the crystal structure, 1 and 2 form an infinite 1‐D chain‐like and 2‐D supramolecular frameworks. EPR spectroscopy of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied. In addition, the calculated HOMO and LUMO energies show the character of HL1, complexes 1 and 2. The electronic transitions and spectral features of HL1 and both complexes were discussed by TD‐DFT calculations. [ABSTRACT FROM AUTHOR]

A new mononuclear Zn(II) complex, [Zn( L)]·CHOH ( HL = 1-(2-{[( E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Zn(II) acetate dihydrate with HL ( HL = 2-(3,5-dichloro-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide) originally. HL and its corresponding Zn(II) complex were characterized by infrared (IR), ultraviolet-visible light (UV-Vis) and emission spectroscopy, as well as by elemental analysis. The crystal structure of the complex has been determined by single-crystal X-ray diffraction (XRD). Each complex links two other molecules into an infinite one-dimensional (1-D) chain through intermolecular hydrogen bonds. Moreover, the calculated highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energies show the character of the ligand HL and the Zn(II) complex. Time-dependent density functional theory (TDDFT) calculations were done on the optimised geometries to understand the electronic structure and spectral transition in the ligand and the Zn(II) complex. Graphical abstract: A new mononuclear Zn(II) complex involving a Schiff base-type instead of an anticipated quinazoline complex has been synthesized and characterized structurally by spectroscopic methods. The crystal structure of the complex has been determined by single-crystal XRD. Each complex links two other molecules into an infinite 1-D chain through intermolecular hydrogen bonds. Moreover, the calculated HOMO and LUMO energies show the character of the ligand HL and the Zn(II) complex. The TDDFT calculations were done on the optimised geometries to understand the electronic structure and spectral transition in the ligand and the Zn(II) complex.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Hydrogen is an ideal energy with little impact on the environment to tackle the intense energy crisis. Development of highly efficient electrocatalysts for low–cost hydrogen production from water splitting is vital for the real-world practical applications. Herein, a three dimensional hierarchical graphdiyne (GDY)@NiFe layered double hydroxide (LDH) heterostructured catalyst toward overall water splitting is developed by coupling NiFe LDH and GDY growth on copper foam (CF). The catalyst exhibits high electrocatalytic activities in both oxygen evolution reaction (OER) and hydrogen evolution reaction with overpotentials of 220 mV and 163 mV at a current density of 10 mA cm−2, respectively. The Tafel slope for OER is 39.33 mV dec−1, which is much lower than that of the only NiFe LDH/CF with a value of 112 mV dec−1. Thus, the GDY@NiFe LDH/CF heterostructure electrocatalyst leads to an improvement in the overall water splitting activity, with a current density of 20 mA cm−2 at the voltage of 1.512 V. Density functional theory calculation indicates that the synergetic effects of 3d orbit of transition metal atoms and carbon–carbon triple bonds in GDY are responsible for the bifunctional excellent electrocatalytic activity for overall water splitting. Image 1 • GDY@NiFe LDH/CF heterostructures for overall water splitting catalyst is firstly reported. • Density functional theory calculation reveals the reaction mechanism. • A solar power assisted water-splitting device was designed. [ABSTRACT FROM AUTHOR]

N-(coumarin-3-yl)-N′-(2-amino-5-phenyl-1,3,4-thiadiazol-2-yl) urea was synthesized and characterized by elemental analysis, IR, 1 H NMR, 13 C NMR, UV–Vis and emission spectroscopy, as well as by single-crystal X-ray diffraction. X-ray crystallographic analyses have indicated that the crystal structure consists of two dimethyl sulfoxide (DMSO) solvent molecules and the structural geometry of DMSO is a trigonal pyramid in shape. In the crystal structure, a self-assembling two-dimensional (2-D) layer supramolecular architecture is formed through intermolecular hydrogen bonds, C O···π (thiadiazole ring) and π···π stacking interactions. The geometry of the compound has been optimized by the DFT method and the results are compared with the X-ray diffraction data. The electronic transitions and spectral features of the compound were carried out by using DFT/B3LYP method. In addition, the antimicrobial activity was also studied, and the highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), and HOMO-LUMO gap were also calculated. [ABSTRACT FROM AUTHOR]

A bridged dinuclear Schiff base-type copper(II) complex, [(Cu 2 ( L 2 ) 2 CH 3 COO)] 2 [Cu(NO 3 ) 4 ]·2CH 3 COOCH 2 CH 3 ( HL 2 = 1-(2-{[( E )-3,5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Cu(II) nitrate trihydrate with HL 1 (2-(3,5-dibromo-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline-3-oxide, H is the deprotonatable hydrogen). During the reaction, the C–N bond in the HL 1 is converted into the C N–OH group in the ligand HL 2 . The Cu(II) complex was analyzed using IR and UV–Vis spectroscopy, elemental analysis and single-crystal X-ray crystallography. The spectroscopic data of the Cu(II) complex was compared with the ligand HL 1 . In the crystal, each complex links with four other molecules into an infinite 2-D supramolecular structure through intermolecular hydrogen bonding and π⋯π stacking interactions. Moreover, the electrochemical properties of HL 1 and Cu(II) complex have been studied by cyclic voltammetry. The powder EPR spectrun of the dinuclear Cu(II) complex indicated that the existence of an antiferromagnetic spin-spin interaction between the magnetically nonequivalent two Cu(II) ions. The geometries and electronic properties of both the ligand HL 1 and the Cu(II) complex were studied by DFT calculation. [ABSTRACT FROM AUTHOR]