The asymmetric unit of the title compound, [Cu(NCS)(2)(C(11)H(17)N(3))], consists of two crystallographically independent mol-ecules. In each mol-ecule, the Cu(II) ion is five-coordinated in a distorted square-pyramidal geometry wherein the basal plane is defined by the N,N',N"-tridentate Schiff base and one N-bound thio-cyanate ligand. The second N-donor thio-cyanate group, located at the apical site, completes the coordination environment. In the crystal, inter-molecular C-H⋯S and C-H⋯N hydrogen bonds link adjacent mol-ecules into infinite layers parallel to the ac plane. Intra-molecular C-H⋯N inter-actions are also observed.
The asymmetric unit of the title compound, [Zn(NCS)(2)(C(13)H(19)N(3)O)], contains two crystallographically independent mol-ecules. In each mol-ecule, the Zn(II) ion is five-coordinated by the N,N',N"-tridentate Schiff base and the N atoms of two thio-cyanate ligands in a distorted square-pyramidal geometry. The two mol-ecules differ mainly in the deviations from the ideal geometry, with τ values of 0.14 and 0.33. In the crystal, inter-molecular C-H⋯S hydrogen bonds are observed. An intra-molecular C-H⋯N hydrogen bond occurs in one of the independent mol-ecules.
In the title compound, [Cu(NCS)(2)(C(13)H(19)N(3)O)], the Cu(II) ion is five-coordinated by the N,N',N''-tridentate Schiff base and the N atoms of two isothio-cyanate ligands in a square-pyramidal geometry. In the crystal, C-H⋯N, C-H⋯O and C-H⋯S inter-actions link adjacent mol-ecules into layers parallel to the ac plane. A weak inter-molecular π-π inter-action occurs between the aromatic rings with a centroid-centroid distance of 3.9412 (9) Å.
In the title compound, [Zn(C(6)H(14)N(2))(2)(H(2)O)(2)]Cl(2), the Zn(II) atom resides on a special position with site symmetry 2/m and is octa-hedrally coordinated by four N atoms from two trans 1,2-diamino-cyclo-hexane ligands and two water O atoms. In the crystal, N-H⋯Cl and O-H⋯Cl hydrogen bonds link the mol-ecules into a two-dimensional network parallel to the bc plane.
In the title compound, C(9)H(14)N(2)O(2), the imidazole ring and the acetate O-C=O plane make a dihedral angle of 80.54 (12)°. In the crystal, mol-ecules are connected via pairs of C-H⋯O hydrogen bonds, forming centrosymmetric dimers.
In the title compound, C(13)H(16)N(2)O(2), the planes of the benzimidazole ring system and the acetate O-C=O fragment make a dihedral angle of 84.5 (3)°. In the crystal, mol-ecules are connected through C-H⋯N hydrogen bonds to form infinite chains in the [-110] direction.
In the title compound, [Cd(NCS)(2)(C(11)H(17)N(3))](n), the Cd(II) atom is octa-hedrally coordinated by the N,N',N''-tridentate Schiff base ligand and one terminal thio-cyanate N atom. Two trans-N:S-bridging thio-cyanates complete the N(5)S donor set around the Cd atom. In the crystal, adjacent Cd(II) ions are linked by the thio-cyanate N:S-bridges into polymeric chains along the c axis.
In the title compound, [Cu(C(21)H(22)N(2)O(2))], the cyclo-hexyl ring adopts a chair conformation with the two imine groups linked at equatorial positions. The Cu(II) ion is coordinated by two N atoms and two O atoms from the bis-Schiff base ligand in a slightly distorted square-planar geometry. The dihedral angle between the two benzene rings is 45.89 (9)°. The crystal structure is devoid of any classical hydrogen bonds. However, inter-molecular C-H⋯O inter-actions are present and stabilize the structure.
The title compound, C(4)H(6)N(4)O·H(2)O, crystallized simultaneously as a triclinic and a monoclinic polymorph from an aqueous solution of 2,4-diaminopyrimidin-6-ol. Previously, an orthorhombic polymorph was isolated under the same experimental conditions. The molecular geometric parameters in the two present polymorphs and the previously reported orthorhombic polymorph are similar, but the structures differ in the details of their crystal packing. In the triclinic system, the diaminopyrimidinone molecules are connected to one another via N-H···O and N-H···N hydrogen bonding to form infinite chains in the [011] direction. The chains are further hydrogen bonded to the water molecules, resulting in a three-dimensional network. In the monoclinic system, the diaminopyrimidinone molecules are hydrogen bonded together into two-dimensional networks parallel to the bc plane. The water molecules link the planes to form a three-dimensional polymeric structure.
The structure of the dinuclear title complex, [Cu(2)(C(5)H(9)O(2))(4)(C(5)H(5)N)(2)], represents a monoclinic polymorph of the previously reported triclinic form [Blewett et al. (2006 ▶). Acta Cryst. E62, m420-m422]. Each carboxyl-ate group is bidentate bridging and the distorted octa-hedral geometry about each Cu(II) atom is completed by a pyridine N atom and the other Cu atom [Cu⋯Cu = 2.6139 (7) Å]. In the crystal, mol-ecules are connected into supra-molecular chains via π-π inter-actions formed by the pyridine rings [centroid-centroid distance = 3.552 (3) Å] and these are connected into a two-dimensional array in the ac plane by C-H⋯π contacts. One of the tert-butyl groups is disordered over two orientations in a 0.734 (6):0.266 (6) ratio.
Alzheimer's disease (AD) is the most common form of dementia among older people and the pathogenesis of this disease is associated with oxidative stress. Acetylcholinesterase inhibitors with antioxidant activities are considered potential treatments for AD. Some novel ketone derivatives of gallic hydrazide-derived Schiff bases were synthesized and examined for their antioxidant activities and in vitro and in silico acetyl cholinesterase inhibition. The compounds were characterized using spectroscopy and X-ray crystallography. The ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays revealed that all the compounds have strong antioxidant activities. N-(1-(5-bromo-2-hydroxyphenyl)-ethylidene)-3,4,5-trihydroxybenzohydrazide (2) was the most potent inhibitor of human acetyl cholinesterase, giving an inhibition rate of 77% at 100 μM. Molecular docking simulation of the ligand-enzyme complex suggested that the ligand may be positioned in the enzyme's active-site gorge, interacting with residues in the peripheral anionic subsite (PAS) and acyl binding pocket (ABP). The current work warrants further preclinical studies to assess the potential for these novel compounds for the treatment of AD.
An octa-nuclear heterobimetallic complex [Y2Cu6Cl0.7(dmae)6(OAc)7.3(OH)4(H2O)2]·3H2O·0.3CH3C6H5 (dmae = dimethylaminoethanoate; OAc = acetato) was synthesized, characterized by melting point analysis, elemental analysis, FT-IR, and single crystal X-ray diffraction analysis and implemented at 600 °C under an oxygen atmosphere for the deposition of Y2CuO4-5CuO composite thin films by aerosol assisted chemical vapor deposition (AACVD). The chemical composition and surface morphology of the deposited thin film have been determined by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis that suggest the formation of impurity-free crystallite mixtures of the Y2CuO4-5CuO composite, with well-defined evenly distributed particles in the size range of 19-24 nm. An optical band gap energy of 1.82 eV was estimated by UV-visible spectrophotometry. PEC studies show that under illumination with a 150 W halogen lamp and at a potential of 0.8 V, a photocurrent density of 9.85 μA cm(-2) was obtained.
The asymmetric unit of the title compound, C(20)H(28)N(2)O(6)S(2), contains one half-mol-ecule, related to the other half by a twofold rotation axis. The two aromatic rings of the mol-ecule make a dihedral angle of 50.91 (7)°. The O-CH(2)-CH(2)-O and N-CH(2)-CH(2)-O fragments both adopt gauche conformations, with torsion angles of 76.0 (4) and 70.4 (3)°, respectively. In the crystal, adjacent mol-ecules are linked through N-H⋯O hydrogen bonds into chains along the a-axis direction. The chains are further connected via C-H⋯O inter-actions into a two-dimensional supra-molecular network in the ac plane.
The two aromatic parts of the title compound, C(16)H(13)ClN(3)O(4), are connected through a conjugated -CH=N-NH-C(O)- fragment, giving an almost planar mol-ecule (r.m.s. deviation 0.08 Å). In the crystal structure, adjacent mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network.
The two aromatic parts of the title mol-ecule, C(16)H(12)BrN(3)O(4), are connected through a conjugated -CH=N-NH-C(O)- fragment to furnish an almost planar mol-ecule. Adjacent mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network. An intramolecular O-H⋯O link also occurs.
A new dibenzotetraaza[14]annulene bearing two 3,3-dimethylindolenine fragments at the meso positions (LH(2)), has been synthesized through a nontemplate method. X-ray crystallography shows that the whole molecule is planar. The basicity of the indolenine ring permits the macrocycle to be protonated external to the core and form LH(4)(2+)·2Cl(-). Yet another structural modification having strong C-H···π interactions was found in the chloroform solvate of LH(2). The latter two modifications are accompanied by a degree of nonplanar distortion. The antiaromatic core of the macrocycle can accommodate a number of metal ions, Mn(III), Fe(III), Co(II), Ni(II) and Cu(II), to form complexes of [Mn(L)Br], [Mn(L)Cl], [Fe(LH(2))Cl(2)](+)·Cl(-), [Co(L)], [Ni(L)], and [Cu(L)]. In addition, the reaction of LH(2) with the larger Pd(II) ion leads to the formation of [Pd(2)(LH(2))(2)(OAc)(4)] wherein the macrocycle acts as a semiflexible ditopic ligand to coordinate pairs of metal ions via its indolenine N atoms into dinuclear metallocycles. The compounds LH(2), [Co(L)], and [Ni(L)] are isostructural and feature close π-stacking as well as linear chain arrangements in the case of the metal complexes. Variable temperature magnetic susceptibility measurements showed thermally induced paramagnetism in [Ni(L)].
A new thiosemicarbazone (LH2) derived from indole-7-carbaldehyde was synthesized and reacted with Zn(II), Cd(II), Pd(II) and Pt(II) salts. The reactions with zinc and cadmium salts in 2 : 1 (ligand-metal) molar ratio afforded complexes of the type MX2(LH2)2, (X = Cl, Br or OAc), in which the thiosemicarbazone acts as a neutral S-monodentate ligand. In the presence of potassium hydroxide, the reaction of LH2 with ZnBr2 resulted in deprotonation of the thiosemicarbazone at the hydrazine and indole nitrogens to form Zn(L)(CH3OH). The reaction of LH2 with K2PdCl4 in the presence of triethylamine, afforded Pd(L)(LH2) which contains two thiosemicarbazone ligands: one being dianionic N,N,S-tridentate while the other one is neutral S-monodentate. When PdCl2(PPh3)2 was used as the Pd(II) ion source, Pd(L)(PPh3) was obtained. In a similar manner, the analogous platinum complex, Pt(L)(PPh3), was synthesized. The thiosemicarbazone in the latter two complexes behaves in a dianionic N,N,S-tridentate fashion. The platinum complex was found to have significant cytotoxicity toward four cancer cells lines, namely MDA-MB-231, MCF-7, HT-29, and HCT-116 but not toward the normal liver WRL-68 cell line. The apoptosis-inducing properties of the Pt complex was explored through fluorescence microscopy visualization, DNA fragmentation analysis and propidium iodide flow cytometry.
The title butterfly-shaped mol-ecule, C(11)H(6)N(2)O(2), is folded slightly along the O=C⋯C=O line, the dihedral angle between the two parts being 6.42 (3)°. In the crystal, adjacent mol-ecules are linked through C-H⋯O hydrogen bonds into infinite layers parallel to the ac plane. The layers are further connected into a three-dimensional netweork via π-π inter-actions formed between pairs of anti-parallel arranged mol-ecules, with a centroid-centroid distance between the central six-membered ring and the benzene ring of 3.4349 (9) Å.
In the trinuclear title compound, [Zn(3)Cl(6)(C(13)H(20)N(4))(2)]·2H(2)O, each terminal Zn(II) atom is coordinated by an N(3) donor set from the Schiff base ligands and two Cl atoms in a distorted square-pyramidal geometry. The central Zn(II) atom is tetra-hedrally coordinated by two piperazine N atoms from two Schiff base ligands and two Cl atoms. The piperazine rings adopt chair conformations. In the crystal structure, adjacent complex mol-ecules are linked into a three-dimensional network via N-H⋯O, C-H⋯Cl and C-H⋯O hydrogen bonds. The structure includes two water mol-ecules, one of which is disordered over two positions with occupancies of 0.753 (15) and 0.247 (15).
Three isomeric 2[Pd(II)-Ni(II)] metal complexes, derived from indoleninyl meso-substituted dibenzotetraaza[14]annulene, were synthesized. The resulting dimers feature Ni···Ni or, alternatively, Ni···π interactions in staggered or slipped cofacial structures. A remarkable insertion of palladium into two different C-H bonds yielded a 4[Pd(II)-Ni(II)] rectangular complex with dimensions of 8.73 × 10.38 Å.