Synthesis and Structure of Copper(II) Complexes with an Imine Derived from 4-nitroaniline and 2-hydroxy-1-naphthaldehyde

In this work, we have focused on the synthesis of a copper(II) complex with an imine derived from 4-nitroaniline (4noa) and 2-hydroxy-1-naphthaldehyde (n), as well as its coordinatively saturated adducts. The obtained metal complex is reasonably soluble in pyridine (py) and tetrahydrofuran (thf), resulting in the formation of two adducts. The complex and adducts have been synthesized both by conventional solvent-based methods and by liquid-assisted grinding (LAG). All products were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and powder X-ray diffraction (PXRD). Their crystal and molecular structures were determined by single crystal X-ray diffraction (SCXRD). The complex crystallizes in the space group P21/c with a = 11.1022(5), b = 9.4550(5), c = 13.7613(7) Å and β = 94.035(4)°. Both adducts crystallize in the space group P with the following lattice parameters: py adduct, a = 9.1696(6) Å, b = 9.4808(9) Å, c = 11.6801(8) Å, α = 93.300(7)°, β = 108.738(6)°, γ = 100.650(7)°; and thf adduct, a = 9.1721(13) Å, b = 9.5797(13) Å, c = 11.4448(15) Å, α = 96.138(11)°, β = 106.466(12)°, γ = 101.543(12)°

Controlling Solvate Formation of a Schiff Base by Combining Mechano-chemistry with Solution Synthesis

A Schiff base dicarboxylic acid (1) was prepared by condensation of 2-hydroxy-1-naphthaldehyde with 5-aminoisophthalic acid. Its solvates with pyridine (2a and 2b) and dimethylformamide (3) were prepared by liquid-assisted grinding and by conventional solvent-based methods. All products were characterised by FT-IR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The structures of 1, 2b and 3 were determined by single crystal X-ray diffraction. 1 was found to be a pure Schiff base, 2b a pyridine solvate and 3 a dimethylformamide solvate monohydrate. In all three structures, the Schiff base molecule appears to be present as the ketoamine tautomer.(doi: 10.5562/cca2111

4-Iodo­anilinium perchlorate

In the crystal structure of the title compound, C6H7IN+·ClO4 −, the ions are connected in a three-dimensional hydrogen-bonded network via N—H⋯O hydrogen bonds

Site-selective quantum correlations revealed by magnetic anisotropy in the tetramer system SeCuO3

We present the investigation of a monoclinic compound SeCuO3 using x-ray powder diffraction, magnetization, torque and electron-spin-resonance (ESR). Structurally based analysis suggests that SeCuO3 can be considered as a 3D network of tetramers. The values of intra-tetramer exchange interactions are extracted from the temperature dependence of the susceptibility and amount to ~200 K. The inter-tetramer coupling leads to the development of long-range antiferromagnetic order at TN = 8 K. An unusual temperature dependence of the effective g-tensors is observed, accompanied with a rotation of macroscopic magnetic axes. We explain this unique observation as due to site-selective quantum correlations

Tautomeric Equilibrium of an Asymmetric β-Diketone in Halogen-Bonded Cocrystals with Perfluorinated Iodobenzenes

In order to study the effect of halogen bond on tautomerism in β-diketones in the solid-state, we have prepared a series of cocrystals derived from an asymmetric β-diketone, benzoyl-4-pyridoylmethane (b4pm), as halogen bond acceptor and perfluorinated iodobenzenes: iodopentaflourobenzene (ipfb), 1, 2-, 1, 3- and 1, 4-diiodotetraflorobenzene (12tfib, 13tfib and 14tfib) and 1, 3, 5-triiodo-2, 4, 6-trifluorobenzene (135titfb). All five cocrystals are assembled by I···N halogen bonds involving pyridyl nitrogen and iodoperfluorobenzene iodine resulting in 1:1 (four compounds) or 1:2 (one compound) cocrystal stoichiometry. Tautomer of b4pm in which hydrogen atom is adjacent to the pyridyl fragment was found to be more stable in vacuo than tautomer with a benzoyl hydroxyl group. This tautomer is also found to be dominant in the majority of crystal structures, somewhat more abundantly in crystal structures of cocrystals in which additional I···O halogen bond with the benzoyl oxygen has been established. Attempts have also been made to prepare an equivalent series of cocrystals using a closely related asymmetric β-diketone, benzoyl-3-pyridoylmethane (b3pm) ; however, all attempts were unsuccessful, which is attributed to more effective crystal packing of b3pm isomer compared to b4pm, which reduced the probability of cocrystal formation