S. A. Borodkin

Coordination silver polymer with the bridging anion of oxadiazolylacrylic acid: Synthesis, crystal structure, and luminescence properties

Metal complex [AgL] (I) is synthesized by the reaction of AgNO3 with 3-(5-furyl-1,3,4-oxadiazol-2-yl)acrylic acid (HL, C9H6N2O4), and its crystal structure is determined (CIF file CCDC no. 1426528). The crystals are monoclinic, space group P21/n, a = 4.946(1), b = 20.084(1), c = 9.015(1) Å, β = 92.32(1)°, V = 894.482 Å3, ρcalcd = 2.442 g/cm3, Z = 4. In structure I, pairs of centrosymmetric silver atoms are bound by bidentate-bridging oxygen atoms of two anions L into dimeric blocks. The Ag–Ag distance in the dimer is 2.854(1) Å. The coordination sphere of Ag+ contains two oxygen atoms, one silver atom, and one nitrogen atom of the diazolyl fragment of the adjacent anion. The coordination polyhedron of Ag+ is a strongly distorted tetrahedron. The molecular packing of crystal I is built of infinite ribbons (AgL)n extended along the direction [001]. The photoluminescence spectrum of compound I contains intense bands about 550 nm corresponding to the green spectral range and less intense bands at 425 and 485 nm.

New Tridentate Schiff Base, Product of Condensation of 4-Methyl-7-hydroxy-8-formylcoumarin and N-Aminomercaptotriazole: Synthesis, Structure, and Complex Formation

A new Schiff base was prepared by the reaction of 4-methyl-7-hydroxy-8-formylcoumarin with N-aminomercaptotriazole. In solution and in solid phase the compound was shown to exist in the thione form. The compound reacts with Cu(II), Ni(II), Zn(II) and Cd(II) ions depending on the metal salt to give complexes of composition ML2 or MHLX, where HL is monodeprotonated form of the ligand. Cu(II) and Ni(II) complexes were studied by spectral and magnetochemical methods. The Zn(II) and Cd(II) complexes exhibit fluorescence.

Binuclear Cyclic Silver(I) Complex with the Anion of 4-[(2-Diphenylphosphanylphenyl)methyleneamino]benzoic Acid: Synthesis, Structure, and Optical Properties

Abstract4-[(2-Diphenylphosphanylphenyl)methyleneamino]benzoic acid (HL) is obtained by the condensation of o-diphenylphosphinobenzaldehyde and p-aminobenzoic acid. The reaction of AgNO3 and HL affords complex [Ag2L2] · H2O (I). The structure of complex I is determined by X-ray structure analysis (CIF file CCDC 1575064), and its reflectance and luminescence spectra are studied. Binuclear complex I is a cyclic molecule in which each of two silver(I) atoms coordinates one phosphorus atom and one oxygen atom of two bridging anions L. Compound I is characterized by emission in a range of 430–740 nm at λexc = 340 and 395 nm.

EPR spectral study of copper(II) chelates with hetarylhydrazones of glyoxylic acid

Structure of copper(II) chelates based on glyoxylic hetarylhydrazones containing benzazole (quinoxaline and phthalazine) fragments have been studied by EPR spectroscopy. Spectral parameters in polycrystalline state and dimethylformamide solutions have been determined. Spectral parameters of benzimidazole derivative are typical for square planar structure of the chelate node, while phthalazine derivative displays formation of polymeric structures due to reduction of copper(II) atom.

Copper(II), nickel(II), and zinc(II) complexes with o -tozylaminobenzaldehyde 4,6-dimethylpyrimidyl hydrazone

Abstracto-Tosylaminobenzaldehyde dimethylpyrimidyl hydrazone and its copper(II), nickel(II), and zinc(II) complexesare synthesized and studied. According to the X-ray diffraction data, the zinc(II) complex has the structure of a tetragonal pyramid with the N3O donor ligand environment. According to EPR and magnetochemistry data, the copper(II) complex has a similar structure of the chelate core. In the nickel(II) complex, the solvent molecule completes the coordination core to an octahedron.

A new ligand system containing sulfanilamide and quinazolinone fragments: Synthesis, structure, and properties

A new Schiff base ligand, 4-methyl-N-{2-[(2-methyl-4-oxo-3,4-dihydroquinazolin-3-yl)iminomethyl]-phenyl}benzenesulfonamide (L), and its complexes with transition metals [Cd(L)2], [Zn(L)2], and [CuLOAc] have been synthesized. The structure and electronic properties of the ligand have been studied by quantum chemical methods, and its zinc and cadmium complexes have been found to exhibit luminescence properties.

Crystal structure of copper(II) 2-methyl-3-{[3-methyl-5-oxo-1-phenylpyrazole-4-ylidene-methyl]amino}-quinazoline-4-onate

The crystal and molecular structure of a copper(II) complex based on 2-methyl-3-{[3-methyl-5-oxo-1-phenylpyrazole-4-ylidene-methyl]amino}-quinazoline-4-one is studied by single crystal X-ray diffraction. The chelate core is demonstrated to have a pyramidal structure.

Molecular and crystal structure of a novel Schiff base: 4-methyl-N-[2-[(2-methyl-4-oxo-quinazoline-3-yl)iminomethyl]phenyl]benzenesulfonamide

A novel Schiff base is synthesized by condensation of 4-methylphenylsulfonyl-2-benzaldehyde and N-aminoquinazoline-4-one. The molecular and crystal structure of the produced compound is determined by the XRD method. It is found that the crystal contains two independent molecules between which a π-stacking interaction occurs.

Four- and five-coordinate metal atoms in a supramolecular polymeric assembly of silver(I) with (4-methyl-2-quinolylthio)acetate

The coordination compound [Ag2L2(H2O)2] · 2H2O (I), L = C12H10NO2S has been synthesized by the reaction of AgNO3 with 4-methyl-2-quinolylthioacetic acid (HL) preliminarily neutralized with an equimolar amount of NBu4OH. Its crystal structure has been determined, and luminescence properties have been studied. Crystals of I are monoclinic, space group C2/c, a = 31.239(6) Å, b = 12.056(2) Å, c = 16.846(3) Å, β = 122.17(3)°, V = 5370.4(2) Å3, ρcalc = 1.861 g/cm3, Z = 16. The structure is formed by two crystallographically nonequivalent silver atoms Ag(1) and Ag(2) and two tridentate bridging ligands L coordinated through the S, N, and O atoms. These atoms, together with water molecules, form the coordination environments of the metal atoms with CN = 5 and 4, respectively. The Ag+ ions and the tridentate ligands form infinite [Ag4L4]n bands extended in the [001] direction. The presence of outer-sphere water molecules involved in O–H···O hydrogen bonding is responsible for the formation of a supramolecular framework structure. The photoluminescence spectrum of compound I shows two bands at ~450 and ~485 nm corresponding to the blue spectral range.

Interaction of Phosphorus Iminoilides with Metal Acetates. Crystal and Molecular Structure of Cu[(2-O–)(5-NO2)C6H3N–CH=CH–+PPh3]2 · 2CHCl3

The structure of the Cu[(2-O–)(5-NO2)C6H3N–CH=CH–+PPh3]2 complex with the CuN2O2 coordination core of distorted square-planar geometry was established by X-ray diffraction analysis. The molecules in the crystal structure of the Cu[(2-O–)(5-NO2 )C6H3N–CH=CH–+PPh3 ]2 · 2CHCl3 solvate are bound via hydrogen bonds of two types, namely, C(sp2)–H···O and C(sp3)–H···O.