catena-Poly[[silver(I)-μ-4-aminopyridine] perchlorate]: a 1-D staircase coordination polymer

Reaction of 4-amino­pyridine with silver(I) perchlorate leads to a one-dimensional coordination polymer, {[Ag(C5H6N2)]ClO4}n, in which the amino­pyridine binds through both N atoms. The perchlorate anion is hydrogen bonded to the amino H atoms and inter­acts weakly with the silver(I) atoms (Ag—O > 2.70 Å), both located on inversion centres, and some aromatic H atoms (O—H > 2.55 ÅA), thereby extending the dimensionality of the assembly. This is the first silver complex in which this ligand acts in a bridging mode

Ferromagnetice exchange in bichloride bridged Cu(II) chains: magnetostructural correlations between ordered and disordered systems

The synthesis, structure, magnetic properties, and theoretical analysis of a new phase of dichloro(2-thlaro-3-methylpyridine)copper(II) (2) and its isomorphous analogue dichloro(2bromo-3-methylpyridine)copper(II) (3) are reported. Both complexes crystallize in the orthorhombic space group Pbca and present square pyramidal Cu(II) ions bridged into chains by chloride ions with each,copper(II)-bearing a single pyridine ligand. Variable temperature magnetic Susceptibility measurements were well fit by a uniform one-dimensional ferromagnetic chain model with,2) J = 69.0(7) K, C = 0.487 emu-K/mol-Oe; 3, J = 73.9(4) K, C = 0.463 emu-K/mol-Oe = Hamiltonian). The experimental J-values were confirmed-via theOretical calculations. Comparison to a known disordered polymorph of dichloro(2-chloro-3-inethylpyridine)copper(II), 1, shows marked differences as there are significant antiferromagnetic next-nearest neighbor interactions, in 1 in addition to randomness induced by the disorder which provide a distinctly different magnetic response. The differences in magnetic behavior are attributed principally to the structural difference in the Cu(II) coordination sphere, 1 being significantly closer to trigonal-bipyramidal, whose difference changes both the nearest and next-nearest neighbor interactions

Aqua(azido)[N-(pyridin-2-ylcarbonyl)pyridine-2-carboxamido-κ3N,N′,N′′]copper(II)

The title compound, [Cu(C12H8N3O2)(N3)(H2O)], was formed by the air oxidation of 2-(aminomethyl)pyridine in 95% ethanol in the presence of copper(II) nitrate and sodium azide with condensation of the resulting picolinamide molecules to generate the imide moiety. The CuII ion has a square-pyramidal coordination sphere, the basal plane being occupied by four N atoms [two pyridine (py) N atoms, the imide N atom and an azide N atom] in a nearly planar array [mean deviation = 0.048 (6) Å] with the CuII ion displaced slightly from the plane [0.167 (5) Å] toward the fifth ligand. The apical position is occupied by a coordinating water molecule [Cu—O = 2.319 (4) Å]. The crystal structure is stabilized by hydrogen-bonding interactions between the water molecules and carbonyl O atoms. The inversion-related square-pyramidal complex molecules pack base-to-base with long Cu...Npy contact distances of 3.537 (9) Å, preventing coordination of a sixth ligand

Hexaaquacopper(II) bis(tetrafluoridoborate)–pyrazine 1,4-dioxide (1/3)

The crystal structure of the title compound, [Cu(H2O)6](BF4)2·3C4H4N2O2, comprises discrete [Cu(H2O)6]2+ cations and BF4− anions along with three equivalents of pyrazine 1,4-dioxide (pzdo). The hexaaquacopper(II) ion and all three pzdo molecules lie about crystallographic inversion centers. The lattice is supported by an extensive hydrogen-bonding network. O—H...O hydrogen bonding between the [Cu(H2O)6]2+ and pzdo units creates a pseudo-hexagonal lattice parallel to the bc plane. The BF4− anions lie in the voids of that lattice, held in place by O—H...F hydrogen bonds, and also generate BF4−–pzdo–BF4−–pzdo stacks via short F...N contacts [2.866 (3)–3.283 (4) Å]

Copper(II) halide salts of 5-bromo-2-aminopyridine and 3,5-dibromo-2-aminopyridine: syntheses, structures and magnetic behavior

Two 5-bromo-2-aminopyridinium quantum Heisenberg antiferromagnetic (QHAF) complexes of copper(II) have been synthesized and studied structurally and magnetically. The structures of (5-BAPH)2[CuCl4] (1) and (5-BAPH)(3,5-diBAPH)[CuBr4] (2) are reported [5-BAPH = 2-amino-5-bromopyridinium; 3,5-diBAPH = 2-amino-3,5-dibromopyridinium]. Single-crystal X-ray diffraction measurements show that 1 crystallizes in the triclinic space group Pī and 2 crystallizes in the monoclinic space group P21/c. Both products crystallize with a four-coordinate Cu(II) ion and are stabilized with extensive hydrogen bonding between the halide ions and pyridinium and amino substituents on each cation. The tetrahalidocuprate ions in 1 and 2 exist in distorted geometries between square planar and tetrahedral with mean trans angles of 139.48° and 131.85°, respectively. Halogen bonding is also observed. Magnetic susceptibility data were collected on 1 and 2. Magnetic susceptibility data of 1 exhibit moderate antiferromagnetic interactions which are best fit using an alternating chain model [CC = 0.4262(3) cm3 K mol−1, J/kB = −22.75(2) K, α = 0.134(3)]. Magnetic susceptibility data of 2 exhibit weak antiferromagnetic interactions, best fit using a uniform chain model [CC = 0.410(6), J/kB = −6.1(4) K]. © 2023 Informa UK Limited, trading as Taylor & Francis Group

4-Cyclohexyl-1-(2-methoxybenzoyl)thiosemicarbazide with an unknown solvent

In the title compound, C15H21N3O2S, a short intramolecular N—H...O hydrogen bond generates an S(6) ring. The molecule is twisted with a dihedral angle between the benzene ring and the mean plane of the cyclohexyl ring being 58.90 (6)°. In the crystal, inversion dimers are formed with each molecule linked to the other by two N—H(H)...O hydrogen bonds to the same acceptor, generating R21(6) loops. A region of disordered electron density was corrected for using the SQUEEZE routine in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. The given chemical formula and other crystal data do not take into account the unknown solvent molecule(s)

Pyridyl-imidazole copper compounds

Three 4-(2’-pyridyl)imidazole (4-pyim) complexes of copper(II) have been synthesized and studied structurally and magnetically. The structures of [CuCl2(4-pyim)] (1), [CuCl(4-pyim)2]2Cl2(H2O)10 (2), and [Cu(CuCl4)(4-pyim)2][Cu(H2O)(4-pyim)2](CuCl4)(H2O)4 (3) are reported. Single-crystal X-ray diffraction measurements show that 1 crystallizes in the monoclinic space group P21/n with a four-coordinate Cu(II) ion forming dimers via semi-coordinate bonds to bridging chloride ions. The structure of 1 shows the copper and chloride ions disordered over two sites. Compound 2 crystallizes in the triclinic space group P–1 with five-coordinate Cu(II) ions in a highly distorted geometry between square pyramidal and trigonal bipyramidal. It has an extensive hydrogen bonding network created by 10 lattice water molecules, chloride ions, and nitrogen atoms in the ligands. Compound 3 crystallizes in the monoclinic space group Cc with both four- and five-coordinate Cu(II) ions present in the lattice; the five-coordinate Cu(II) ions display highly distorted geometries. All three compounds have hydrogen bonding and π-stacking interactions among the 4-pyim rings. Magnetic susceptibility data were collected on 1. Magnetic susceptibility data of 1 shows that it exhibits modest antiferromagnetic interactions which are best fit using a honeycomb model [(2J = −2.6(2) K), 2J’ = −1.6(2) K, (Formula presented.) ]. Disorder in the crystal structure decreases the rate of growth of the correlation length at low temperatures, lowering the temperature of the expected maximum in χ below the range of the data. © 2023 Informa UK Limited, trading as Taylor & Francis Group

Synthesis, structure, and magnetic properties of a family of Mn(II) compounds with substituted 2-aminopyridinium ions

A family of complexes were made by combining MnX2·nH2O (X = Cl, Br) with 2-amino-3-methylpyridine (3MAP), 2-amino-5-methylpyridine (5MAP) or 2-amino-5-iodopyridine (5IAP) in aqueous acidic conditions. The resulting complexes were (3MAPH)2Cl2.MnCl2(H2O)2 (1), (3MAPH)2Br2.MnBr2(H2O)2 (2), (5IAPH)8 [Mn4Cl10(H2O)8] Cl6 (3) and (5MAPH)2 MnBr4 (4). Complexes 1–3 crystalize in monoclinic space groups (1 = P21/c, 2&3 = P21/n) with chains formed by halide bridged manganese ions. Compound 4 crystalizes in the triclinic space group P-1 with a manganese halide ladder structure formed via short Br…Br contacts. Complexes 1, 2 and 4 were studied through variable temperature magnetic susceptibility measurements, all of which exhibited weak antiferromagnetic interactions (J = ~ – 0.45 to –0.05 K)