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The quinazoline‐type ligand 2‐(4‐diethylamino‐2‐hydroxyphenyl)‐4‐methyl‐1,2‐dihydroquinazoline 3‐oxide (HL1; H is the deprotonatable hydrogen) was prepared. Two 2‐D supramolecular complexes [Cu2(L2)2(NO3)2] (1) and [Ni2(L2)2(CH3COO)2] (2) (L2 = 1‐(2‐{[(E)‐(4‐diethylamino‐2‐hydroxybenzylidene]amino} phenyl)ethanone oxime) were synthesized using HL1 and characterized by elemental analysis, spectroscopic methods, and single‐crystal X‐ray diffraction studies. It revealed that 1 had coordinated two nitrate ions whereas 2 had acetate ions. In the crystal structures, six‐coordinated Cu (II) complex 1 formed an infinite 2‐D and X‐shaped 3‐D supramolecular frameworks. Simultaneously, Ni (II) complex 2 assembled into wavy 2‐D networks. Furthermore, electrochemical properties and antimicrobial activities of all compounds were as well investigated. Afterwards, the electrophilic and nucleophilic attack sites identified by electrostatic potential (ESP) calculations confirmed that hydrogen bonds were observed in the optimized structure of the crystal, and the closest contact between the active atoms of both complexes was confirmed through Hirshfeld surface analysis and time‐dependent density functional theory (TD‐DFT) calculations. [ABSTRACT FROM AUTHOR]

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]

Two two-dimensional supramolecular copper(II) and cobalt(III) complexes, Cu(L1)2 ( 1; HL1 = 2-hydroxy-3-methoxybenzaldehyde oxime) and [Co(L2)2]2⋅2CH3COOCH2CH3 ( 2; HL2 = 1-(2-{[( E)-3-methoxy-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), have been synthesized via complexation of Cu(II) nitrate trihydrate and Co(II) acetate tetrahydrate with HL. A plausible reaction mechanism for the formation of HL1 is proposed. HL was synthesized and characterized using infrared, 1H NMR and 13C NMR spectra, as well as elemental analysis. Complexes 1 and 2 were investigated using single-crystal X-ray diffraction and have a 2:1 ligand-to-metal ratio. Different geometric features of both complexes are observed. In their crystal structures, 1 and 2 form infinite two-dimensional structures and 2 forms a three-dimensional supramolecular framework. Electron paramagnetic resonance spectra of 1 and 2 were also investigated. Moreover, thermal and electrochemical properties and antimicrobial activity of 2 were also studied. In addition, the calculated HOMO and LUMO energies show the character of complex 1. [ABSTRACT FROM AUTHOR]

Two mono- and dinuclear Ni(II) complexes, [Ni( L 3 ) 2 ]·2H 2 O ( 1 ) ( HL 3 = 1-(2-{[( E )-3-methoxy-2-hydroxybenzylidene]amino}phenyl)ethanone oxime) and [Ni 2 ( L 4 ) 2 (CH 3 COO) 2 ] ( 2 ) ( HL 4 = 1-(2-{[( E )-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), have been synthesized via complexation of Ni(II) acetate tetrahydrate with HL 1 and HL 2 ( HL 1 = 2-(2-hydroxy-3-methoxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide, HL 2 = 2-(2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide) originally. HL 1 , HL 2 , and two Ni(II) complexes were characterized by IR, UV–Vis, and fluorescence spectroscopy, as well as by elemental analysis, respectively. The spectroscopic data of two Ni(II) complexes were compared with the ligands HL 1 and HL 2 . The differently geometric features of the obtained complexes 1 and 2 are observed by X-ray crystallography. In the crystal structure, complexes 1 and 2 form an infinite 1-D chain and 2 into 2-D supramolecular frameworks. The electrochemical properties of 1 and 2 were also investigated by cyclic voltammetry. Moreover, thermal property of 1 was also studied. In addition, the antimicrobial activity of HL 1 , HL 2 , and complexes 1 and 2 were also investigated. [ABSTRACT FROM AUTHOR]

A new dinuclear Co(III) complex, [Co 2 ( L 1 ) 2 ( L 2 ) 2 ] ( HL 1 = ( E )-1-(2-aminophenyl) ethanone oxime, HL 2 = 2-(2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide, H is the deprotonatable hydrogen) has been synthesized via complexation of Co(II) nitrate hexahydrate with HL 1 and HL 2 . The structure of the Co(III) complex was characterized by infrared, UV–Vis spectroscopy, elemental analysis, and single-crystal X-ray crystallography. Elemental analysis was in good agreement with the proposed structure. The spectroscopic data of the Co(III) complex was compared with the ligand HL 2 . In the crystal structure, each complex links with two other molecules into an infinite 2-D layer supramolecular structure through intermolecular hydrogen bonding and π···π stacking interactions. Moreover, the electrochemical property of the Co(III) complex was studied by cyclic voltammetry. Electron paramagnetic resonance (EPR) spectroscopy of the dinuclear Co(III) complex was also investigated. In addition, the antimicrobial activity of HL 2 and the Co(III) complex were also studied. [ABSTRACT FROM AUTHOR]

Two mononuclear M(II) complexes, [M( L 2 ) 2 ]·CH 3 OH (M = Mn( 1 ) and Zn( 2 ), HL 2 = 1-(2-{[( E )-3,5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), were synthesized via complexation of corresponding M(II) acetate with HL 1 (2-(3,5-dibromo-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline-3-oxide, H is the deprotonatable hydrogen) originally. During the reaction, the C–N bond in the ligand HL 1 is converted into the C N OH group in the HL 2 . The spectral data of both complexes were compared with the ligand HL 1 . Both complexes were determined by single crystal X-ray diffraction and display similar coordination geometry and have a 2:1 ligand-to-metal ratio. In the crystal structure, complexes 1 and 2 form an infinite 1-D chain and 2 into 3-D supramolecular frameworks. The electrochemical property of complex 1 was investigated by cyclic voltammetry. The electronic transitions and spectral features of HL 1 and both complexes were discussed by DFT and TD-DFT calculations. Time dependent DFT calculations have been carried out on the optimised geometry to further understand the electronic transitions in the UV–Vis spectra of the compounds. In addition, 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]

Two new cobalt(II) complexes, [Co(L3)2]·CH3OH·CH3COCH3(1) (HL3= 1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime) and Co(L4)2(2) (HL4= 1-(2-{[(E)-3,5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), have been synthesized via complexation of Co(II) acetate tetrahydrate withHL1andHL2.HL1,HL2,and their corresponding Co(II) complexes were characterized by IR,1H NMR spectra, as well as by elemental analysis and UV–Vis spectroscopy, respectively. The crystal structures of the complexes have been determined by single-crystal X-ray diffraction.1and2display that extensive hydrogen bonds and C–X···πbonding interactions construct the 1-D infinite chain [Co(L3)2]·CH3OH·CH3COCH3and Co(L4)2into 2-D supramolecular frameworks. The electrochemical properties of two Co(II) complexes were also investigated by cyclic voltammetry. Two new cobalt(II) complexes have been synthesized via complexation of Co(II) acetate tetrahydrate withHL1andHL2originally.HL1,HL2and their corresponding Co(II) complexes were characterized by IR,1H NMR spectra, as well as by elemental analysis and UV–Vis spectroscopy, respectively. The crystal structures of the complexes have been determined by single-crystal X-ray diffraction.1and2display that extensive hydrogen bonds and C-X···π bonding interactions construct the 1-D infinite chain [Co(L3)2]·CH3OH·CH3COCH3and Co(L4)2into 2-D supramolecular frameworks. The electrochemical properties of two Co(II) complexes were also investigated by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

An unexpected Schiff base-type Ni(II) complex, [Ni( L 2 ) 2 ]⋅CH 3 OH ( HL 2 = 1-(2-{[( E )-3, 5-dibromo-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Ni(II) acetate tetrahydrate with HL 1 (2-(3,5-dibromo-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide) originally. HL 1 and its corresponding Ni(II) complex were characterized by IR, 1 H NMR spectra, as well as by elemental analysis, UV–Vis and emission spectroscopy, respectively. Crystal structures of the ligand and complex have been determined by single-crystal X-ray diffraction. Each complex links two other molecules into an infinite 1-D chain via intermolecular hydrogen bonding interactions. Moreover, the electrochemical property of the nickle complex was studied by cyclic voltammetry. In addition, SOD-like activities of HL 1 and Ni(II) complex were also investigated. [ABSTRACT FROM AUTHOR]

Highlights: [•] An unexpected mononuclear Co(III) complex has been synthesized and structural characterized. [•] Single crystal X-ray analysis reveals that the valence of cobalt ion is trivalent. [•] Cyclic voltammetry and XPS experiment also proved that cobalt ion is trivalent. [ABSTRACT FROM AUTHOR]

An unexpected mononuclear Ni(II) complex, [Ni(L2)2]·CH3OH (HL2 = 1-(2-{[(E)-3,5-dichloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), has been synthesized via complexation of Ni(II) acetate tetrahydrate with HL1. HL1and its corresponding Ni(II) complex were characterized by IR,1H-NMR spectra, HRMS, as well as by elemental analysis, UV–vis, and emission spectroscopy. The crystal structure of the complex has been determined by single-crystal X-ray diffraction. Each complex links two other molecules into an infinite 1-D chain via intermolecular hydrogen bonds. Moreover, the electrochemical properties of the nickel complex were studied by cyclic voltammetry. Superoxide dismutase-like activities of HL1and Ni(II) complex were also investigated. [ABSTRACT FROM PUBLISHER]

• The Cd(II) coordination polymer was synthesized and structural characterized by spectroscopic methods and single-crystal X-ray diffraction. • The solid-state luminescence properties of L and Cd(II) coordination polymer were measured. • Time dependent DFT calculations on the optimized structure of the Cd(II) complex allowed for the assignment of specific electronic transitions in the UV–Vis spectrum. • The calculated HOMO and LUMO energies show the character of the Cd(II) complex and the nucleophilic and electrophilic attack sites were confirmed with electrostatic potential (ESP) calculations. • Non-covalent supramolecular interactions in the crystal structure were quantified by means of Hirshfeld surface analysis. A novel 1-D, 2-D, 3-D supramolecular cadmium(II) coordination polymer [Cd(L) 4 (NO 3) 2 ] n (L = 4-methyl-2-(pyridin-3-yl)-1,2-dihydroquinazoline N3-oxide) was synthesized and characterized by elemental analysis and spectroscopic methods at solid-state, as well as determined by X-ray crystallographic. X-ray structure revealed that had 4:1 ligand-to-metal ratio and was best described as slight distorted octahedral geometry with six-coordinated environment. In particular, it fostered into an infinite one-dimensional (1-D) chains coordination polymer without any non-covalent interactions. The geometry optimization and HOMO, LUMO energies level calculations were performed using DFT methods. Specifically, the electronic transitions and spectral features were carried out by TD-DFT calculations. The electrostatic potential (ESP) analysis was utilized to visualize electrophilic and nucleophilic attack sites on the molecule, which verified the existence of hydrogen bonds in the optimized geometry. In addition, the solid-state luminescence and electrochemical property of Cd(II) complex was also investigated. The non-covalent interactions of Cd(II) coordination polymer was quantified with Hirshfeld surface analysis using the CrystalExplorer program. A new 1D chain Cd(II) coordination polymer, [Cd(L) 4 (NO 3) 2 ] n , was synthesized and characterized by elemental analysis and spectroscopic methods at solid-state. The Cd(II) coordination polymer was in six-coordinated environment and developed into an infinite 1-D chain, 2-D layer and 3-D supramolecular framework. The structural of Cd(II) coordination polymer have been amended markedly and the HOMO, LUMO energies level were calculated by TD/DFT. The electrostatic potential (ESP) calculations were utilized to analyse electrophilic and nucleophilic attack sites on the molecule. The consequence of cyclic voltammetry of Cd(II) coordination polymer revealed an irreversible couple Cd(II)/Cd(0) reduction process. The non-covalent interactions were quantified with Hirshfeld surfaces using the CrystalExplorer program. [Display omitted] [ABSTRACT FROM AUTHOR]

Two two‐dimensional and three‐dimensional supramolecular complexes [M (L)2] (NO3)2·2CH3OH (M = Cu(1) and Co(2), L = 2‐(4‐imidazolyl)‐4‐methyl‐1,2‐quinazoline‐N3‐oxide), were synthesized and characterized by FT‐IR and UV–Vis spectroscopy, as well as elemental analysis. The spectroscopic data of both complexes were compared with the ligand L. Both complexes were determined by X‐ray single‐crystal diffraction and display similar coordination geometry and have a 2:1 ligand‐to‐metal ratio. All the central M (II) atoms are hexa‐coordinated with perfect octahedral geometries. In the crystal structures, complexes 1 and 2 form an infinite 1‐D chain‐like and 2‐D, 3‐D supramolecular frameworks. X‐ray photoelectron spectrum (XPS) and thermal stability of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied. Two 2‐D and 3‐D supramolecular complexes [M(L)2] (NO3)2•2CH3OH (M = Cu(1) and Co(2), L = 2‐(4‐imidazolyl)‐4‐methyl‐1,2‐quinazoline‐N3‐oxide), were synthesized and characterized. The spectroscopic data of complexes were compared with L. Both complexes were determined by X‐ray single‐crysta diffraction and display perfect octahedral geometries. In the crystal structures, complexes 1 and 2 form an infinite 1‐D chain‐like and 2‐D, 3‐D supramolecular frameworks. XPS and thermal stability of 2 was investigated. Electrochemical properties and antimicrobial activities of complexes were also studied. [ABSTRACT FROM AUTHOR]