Methanol Solvent Mol-ecule Research Articles

Synthesis, crystal structure, DNA binding and antitumor studies of β-diketonate complexes of divalent copper, zinc and palladium

This paper reports a simple approach for the synthesis of three pairs of novel mononuclear β-diketonate complexes of copper(II), zinc(II) and palladium(II) from monobasic O^O donor ligands 3-phenyl-4-fluorobenzolyl-5-isoxazolone (HL1) and 3-phenyl-4-toluyl-5-isxoazolone (HL2). The synthesized compounds are characterized by FT-IR, ESI/FAB mass, 1H NMR, UV–visible and thermogravimetric analyses. The free ligand HL1 and the copper(II) complex, [Cu(L2)2(CH3OH)2] are unambiguously characterized by single crystal X-ray diffraction studies. The free ligand HL1 has adopted orthorhombic crystal system with P2(1) space group and the unit cell parameters are a=8.1552(3), b=10.1169(4), c=17.0819(6) Å, and α=β=γ=90°. The crystal structure of the complex, [Cu(L2)2(CH3OH)2] is monoclinic with P2(1)/c space group and the unit cell parameters are a=10.2571(2), b=16.2640(3), c=20.1717(3)Å, and α=90, β=99.56 and γ=90°. The copper(II) complex has adopted distorted octahedral geometry where the z-axis is occupied by two solvent methanol molecules according to the crystal data. While the EPR spectra of both the Cu(II) complexes display a strong axial signal with g||≈2.2 and g⊥≈2.0, which obviously suggests the square planar geometry around the copper(II) ion. The interaction of the complexes with calf thymus DNA (CT-DNA) was investigated using UV–visible and fluorescence spectroscopic techniques. Anticancer activity of the complexes revealed their potential towards inhibiting the growth of human breast cancer cell lines, MDA-MB-231. The palladium complexes of both the ligands are found to be good in exhibiting apoptosis. Moreover, the complexes of fluoro-substituted ligand are better antimicrobial agents when compared with those of methyl substituted ligand.

Crystal structure of bis-{1-phenyl-3-methyl-4-[(quinolin-3-yl)imino-methyl-κN]-1H-pyrazol-5-olato-κO}zinc methanol 2.5-solvate from synchrotron X-ray diffraction.

The title compound, [Zn(C20H15N4O)2]·2.5CH3OH, I, was synthesized via the reaction of zinc acetate with the respective ligand and isolated as a methanol solvate, i.e., as I·2.5CH3OH. The crystal structure is triclinic (space group P-1), with two complex mol-ecules ( A and B ) and five methanol solvent mol-ecules in the asymmetric unit. One of the five methanol solvent mol-ecules is disordered over two sets of sites, with an occupancy ratio of 0.75:0.25. Mol-ecules A and B are conformers and distinguished by the conformations of the bidentate 1-phenyl-3-methyl-4-[(quinolin-3-yl)imino-meth-yl]-1H-pyrazol-5-olate ligands. In both mol-ecules, the zinc cations have distorted tetra-hedral coordination spheres, binding the monoanionic ligands through the pyrazolo-late O and imine N atoms. The two ligands adopt slightly different conformations in terms of the orientation of the terminal phenyl and quinoline substituents with respect to the central pyrazolo-late moiety. The mol-ecular geometries of A and B are supported by intra-molecular C-H⋯O and C-H⋯N hydrogen bonds. In the crystal of I, mol-ecules form dimers both by secondary inter-molecular Zn⋯O [3.140 (2)-3.553 (3) Å] and π-π stacking inter-actions. The dimers are linked by inter-molecular hydrogen bonds through the solvent methanol mol-ecules into a three-dimensional network.

A copper(II) complex of a semicarbazone: crystal structure, spectroscopic analysis and cytotoxicity against human cancer cell lines

A Cu(II) complex of 2-hydroxyacetophenone N(4)-phenyl semicarbazone (H2L) has been prepared, and its crystal structure is reported. The single-crystal X-ray study reveals a dimeric structure with a distorted square planar coordination geometry around each copper atom, with an ONO-donor ligand and µ2-oxo group located between the two copper atoms. The secondary coordination sphere of Cu(II) is six-coordinate, with a NO3 − ion and methanol solvent molecule making weak interactions. Supramolecular interactions involving the adjacent complexes were investigated. The complex [Cu(HL)]2(CH3OH)2(NO3)2 was also characterized by physicochemical and spectroscopic methods. The biological activity of the free semicarbazone and its Cu(II) complex were evaluated by cytotoxicity assays against human cancer cell lines. A dimeric stable complex between copper(II) and semicarbazone ligand has been synthesized, and the crystal structure has been studied. Spectroscopy experiments and cytotoxicity assays against human cancer cell lines were performed.

Crystal structure of bromido-fac-tricarbon-yl[5-(3,4,5-tri-meth-oxy-phen-yl)-3-(pyridin-2-yl)-1H-1,2,4-triazole-κ2N2,N3]rhenium(I) methanol monosolvate.

In the title compound, [ReBr(C16H16N4O3)(CO)3]·CH3OH, the ReI atom adopts a distorted octa-hedral coordination sphere with a facial arrangement of the three carbonyl ligands. Two N atoms of the chelating 5-(3,4,5-tri-meth-oxy-phen-yl)-3-(pyridin-2-yl)-1H-1,2,4-triazole ligand and two carbonyl ligands define the equatorial plane of the complex, with the third carbonyl ligand and the bromide ligand in axial positions. Conventional hydrogen bonds including the methanol solvent mol-ecules assemble the complex mol-ecules through mutual N-H⋯O-H⋯Br links [N⋯O = 2.703 (3) Å and O⋯Br = 3.255 (2) Å] into centrosymmetric dimers, whereas weaker C-H⋯O and C-H⋯Br hydrogen bonds [C⋯O = 3.215 (3)-3.390 (4) Å and C⋯Br = 3.927 (3) Å] connect the dimers into double layers parallel to the (111) plane.

Synthesis, characterization, and X-ray structure of n'-(2-hydroxy-5-methylbenzylidene)-4-trifluoromethylbenzohydrazide and its dioxidomolybdenum(vi) complex with catalytic property

ABSTRACTA new hydrazone compound N’-(2-hydroxy-5-methylbenzylidene)-4-trifluoromethylbenzohydrazide (H2L) was prepared. Based on H2L, a new dioxidomolybdenum(VI) complex [cis-MoO2L(MeOH)], was obtained. Single crystals of H2L and the complex were obtained by slow evaporation of methanolic solution containing the compounds, and were characterized by elemental analysis, infrared spectroscopy, and single-crystal X-ray diffraction techniques. The geometry around the molybdenum center is distorted octahedral in which the tridentate benzohydrazone ligand with two anionic oxygens and one neutral imine nitrogen occupies meridional position. The octahedral geometry of the cis-dioxomolybdenum center is additionally completed by a coordinated methanol solvent molecule. The complex was tested for the homogeneous oxidation of various olefins.

Crystal structure of vilazodone hydro-chloride methanol monosolvate.

In the title compound, C26H28N5O2+·Cl-·CH3OH {systematic name: 4-(2-carbamoyl-1-benzo-furan-5-yl)-1-[4-(5-cyano-1H-indol-3-yl)but-yl]piperazin-1-ium chloride methanol monosolvate}, the protonated piperazine ring adopts a chair conformation. The indole ring plane is nearly perpendicular to the benzo-furan ring system, with a dihedral angle of 85.77 (2)°. In the crystal, the organic cations, Cl- anions and methanol solvent mol-ecules are linked by classical N-H⋯O and N-H⋯Cl hydrogen bonds, and weak C-H⋯O and C-H⋯π inter-actions into a three-dimensional supra-molecular architecture.

A tetra-nuclear cubane-like nickel(II) complex with a tridentate salicyl-idene-imine Schiff base ligand: tetra-kis-[μ3-4-methyl-N-(2-oxidophen-yl)salicylideneiminato]tetra-kis-[methano-lnickel(II)] methanol 0.8-solvate.

The tetra-nuclear title complex, [Ni4(C14H11NO2)4(CH3OH)4]·0.8CH3OH, has a distorted cubane topology shaped by four Schiff base ligands. The cubane [Ni4(μ3-O4)] core is formed via the O atoms from the Schiff base ligands. The octa-hedrally coordinated NiII ions occupy alternating vertices of the cube. Each NiII ion is coordinated by one O,N,O'-tridentate dianionic ligand, two O atoms of oxidophenyl groups from adjacent ligands and the O atom of a coordinating methanol mol-ecule. The cubane core is stabilized via an intra-molecular O-H⋯O hydrogen bond between the hy-droxy group of the coordinating methanol mol-ecules and the phenolate O atom of the aldehyde Schiff base fragment. Additional stabilization is obtained via intra-molecular C-H⋯O hydrogen bonds involving aromatic C-H groups and the oxygen atoms of adjacent methanol mol-ecules. In the crystal, complex mol-ecules are linked into chains parallel to the c axis via weak C-H⋯O hydrogen bonds. The partial-occupancy disordered methanol solvent mol-ecule has a site occupancy of 0.8 and is linked to the tetra-nuclear unit via an inter-molecular C-H⋯O hydrogen bond involving a phenolate O atom.

A dinuclear oxygen-bridged Schiff base iron(III) complex derived from N,N′-bis(4-methoxy-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine

The μ-oxo-bridged Fe(III) dimer complex [{Fe(4-MeOL1)}2(μ-O)]∙HOCH3, (H2-4-MeOL1 = N,N′-bis(4-methoxy-2-hydroxybenzylidene)-2,2-dimethylpropane-1,3-diamine), 1 is synthesized and characterized by single crystal X-ray diffraction. Complex 1 contains a [{Fe(4-MeOL1)}2(μ-O)] dimeric unit with a methanol solvent molecule of crystallization. Each Fe(III) ion has a distorted square-pyramidal coordination geometry. In the basal plane, the Fe(III) atom is coordinated by two N and two O atoms of the Schiff base ligand. The apical position is occupied by a bridging O2– ion, linking another Fe(III) ion in the complex. There are intermolecular C–H…O and C–H…π interactions among the dinuclear complexes.

OFF-ON-OFF Dual Emission at Visible and UV Wavelengths from Carbazole Functionalized β-Diketonate Europium(III) Complex.

This work demonstrates dual emission "OFF-ON-OFF" switching at visible and UV wavelengths of a carbazole functionalized β-diketone (LH) by a simple change of a europium(III) ion (Eu(3+)) concentration in the submicromolar concentration range. In the presence of 0.25 equiv of Eu(3+) (5 μM), LH forms a luminescent 4:1 complex ([Eu(3+)(L(-))4](-)) exhibiting dual emission at 357 and 613 nm resulting from the local excitation of the carbazole ring and ligand-sensitized luminescence from the Eu(3+)-β-diketonate unit, respectively. The 4:1 complex begins to convert into a 2:1 complex ([Eu(3+)(L(-))2](+)) via a 3:1 complex [Eu(3+)(L(-))3] above a molar ratio ([Eu(3+)]/[LH]) of 0.25, which provides the opportunity for binding of solvent methanol molecules to the vacant site of the Eu(3+) ion in the complex ([Eu(3+)(L(-))2(MeOH)n](+)). The OH oscillators of coordinated methanol molecules facilitate the nonradiative pathway of the Eu(3+) emission; hence the emission at 613 nm almost disappears above the 0.50 equivalent of Eu(3+) (11 μM), while the UV emission at 357 nm remains mostly constant over the whole concentration range.

A novel binuclear copper complex incorporating a nalidixic acid derivative displaying a one-dimensional coordination polymeric structure.

The identification of the antibacterial action of nalidixic acid (nx) was central to the development of the quinolone antibacterial compounds. The ability of the nx naphthyridyl ring to interact with and inhibit some proteins has encouraged the investigation of similar structures in the search for more active compounds with less adverse effects. The possibility of structural modification by attachment of other biologically active moieties to the naphthyridyl ring of nx allowed the development of new active antimicrobial molecules. Hydrazone derivatives of nx can be synthesized easily based on the condensation of the hydrazide derivative of nx with the desired aldehyde or ketone. Only a few complexes with nx hydrazone derivatives have been described but for none were the crystal structures elucidated. The synthesis of a new one-dimensional Cu(II) coordination polymer, namely catena-poly[[copper(II)-di-μ-chlorido-copper(II)-{μ-1-ethyl-N'-[(1H-imidazol-4-yl)methylidene]-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carbohydrazidato}-[dimethanolcopper(II)]-{μ-1-ethyl-N'-[(1H-imidazol-3-yl)methylidene]-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carbohydrazidato}] dichloride methanol tetrasolvate], {[Cu3(C16H15N6O2)2Cl2(CH3OH)2]Cl2·4CH3OH}n, with the (1H-imidazol-4-yl)methylidene carbohydrazide derivative of nalidixic acid (denoted h4imi), is presented and its structure is compared to the density functional theory (DFT) optimized structure of free h4imi. The title structure presents an octahedral Cu(II) ion on an inversion centre alternating along a polymer chain with a square-pyramidal Cu(II) ion, with the two Cu(II) centres bridged by two chloride ligands. Hydrogen bonds involving chloride counter-ions and methanol solvent molecules mediate the three-dimensional packing of the polymer. Comparison of the geometrical results from the structure analysis with those derived from a DFT study of the free ligand reveal the differences that arise upon coordination.

1-(3′,6′-Dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9′-xanthen]-5-yl)-3-[4-({4-[1-(4-fluorophenyl)-1H-imidazol-5-yl]pyridin-2-yl}amino)phenyl]thiourea methanol monosolvate

The title compound, which crystallized as a methanol monosolvate, C41H27FN6O5S·CH3OH, was synthesized as a probe for a fluorescence polarization-based competition binding assay. The isobenzofuran fused-ring system is close to planar and orientated almost perpendicular to the central ring of the xanthene system. The dihedral angle between the benzene rings of the xanthene system is 10.0 (2)°, indicating a butterfly-like orientation. A short intramolecular C—F...π contact [F...π = 3.100 (4) Å and C—F...π = 139.9 (3)°] to the six-membered ring of the isobenzofuran system may influence the molecular conformation. The methanol solvent molecule is disordered over two orientations in a 0.6:0.4 ratio. In the crystal, the components are linked by numerous hydrogen bonds, generating a three-dimensional network.

Manganese(III) complexes with tetradentate salicylaldimine Schiff bases: Synthesis, structure, self assembly and catalase activity

Three new mononuclear manganese(III) complexes [Mn(L1)(SeCN)(DMSO)] (1), [Mn(L2)(N3)(DMSO)] (2) and [Mn(L3)(CH3OH)2]ClO4 (3) [where H2L1=N,N′-bis((2-hydroxy-1-naphthyl)methylidene)phenyl-1,2-diamine, H2L2=N,N′-bis((2-hydroxy-1-naphthyl)methylidene)-2,2-dimethylpropane-1,3-diamine and H2L3=N,N′-bis(1-(1′-hydroxy-2-naphthyl)ethylidene)propane-1,3-diamine] have been prepared and characterized by elemental and spectral analysis and single crystal X-ray diffraction studies. Complexes 1 and 2 show six-coordinate distorted octahedral geometry around the manganese(III) center and are bonded to the respective deprotonated tetradentate ligands together with a monodentate pseudohalide. The sixth coordination site is occupied by solvent DMSO molecule. Complex 3 is also octahedral, but it is bonded to a deprotonated tetradentate ligand and two solvent methanol molecules. Complex 3 is distinctive in the sense that it catalyzes the disproportionation of hydrogen peroxide into water and dioxygen i.e. it possesses catalase activity. The catalase activity of complex 3 may be related with its structure. Supramolecular interactions in all three complexes were explored.

Density functional theory study of the reactivity and electronic structure of the transesterification of triacetin in biodiesel production via a sulfated zirconia heterogeneous catalysis

This DFT study examined the interaction of a sulfated zirconia (SZ) slab model system (heterogeneous catalyst) and triacetin (a precursor in biodiesel production) using explicit methanol solvent molecules. Full geometry optimizations of the systems were performed at the B3LYP level of theory. Gibbs free energies provide insight into the spontaneity of the reactions along a three-step reaction mechanism for the transesterification of triacetin. Charge decomposition analysis revealed electronic charge transfer between the metallic oxide and the organic moieties involved in the reaction mechanism. Fukui indices indicate the likely locations on the SZ surface where catalysis may occur. The quadratic synchronous transit scheme was used to locate transition structures for each step of the transesterification process. The results are in agreement with the strongly acidic catalytic character of zirconium observed experimentally in the production of biodiesel. © 2016 Wiley Periodicals, Inc.

μ-Sulfido-bis{[1,1′-bis(diphenylphosphanyl)ferrocene-κ2P,P′]gold} methanol monosolvate

The gold complex in title compound, [Au2Fe(C17H14P)2S]·CH3OH, (I)·CH3OH, is closely similar to the previously reported (I)·2CHCl3, reported in the literature [Canaleset al.(1996).J. Am. Chem. Soc.118, 4839–4845]. Both crystallize in the monoclinic crystal systems but the space groups differ,P21/nfor (I)·CH3OH compared toP2/nfor (I)·2CHCl3. The two structures can be considered as polymorphs due to solvation differences. In (I)·CH3OH, all atoms of the methanol solvent molecule are disordered over two sets of sites with an occupancy ratio of 0.822 (12):0.178 (12). The crystal structure features O—H...S, C—H...S hydrogen bonds and C—H...π interactions that stack the complex molecules along thea-axis direction.

A novel crystal structure of {tris[4-(1H-pyrazol-3-yl-κN(2))-3-azabut-3-enyl]amine-κN}iron(II) bis(tetrafluoridoborate) methanol monosolvate featuring a low-spin configuration.

Mononuclear complexes are good model systems for evaluating the effects of different ligand systems on the magnetic properties of iron(II) centres. A novel crystal structure of the title compound, [Fe(C18H24N10)](BF4)2·CH3OH, with one molecule of methanol per formula unit exhibits a strictly sixfold coordination sphere associated with a low-spin configuration at the metal centre. The incorporated methanol solvent molecule promotes extended hydrogen-bonding networks between the tetrafluoridoborate anions and the cationic units. A less constrained crystal structure regarding close contacts between the tetrafluoridoborate anions and the cationic units allows a spin transition which is inhibited in the previously published hydrate of the title compound.

Crystal structure of bis-{1-[(E)-(2-meth-oxy-phen-yl)diazen-yl]naphthalen-2-olato-κ(3) O,N (2),O'}copper(II) containing an unknown solvate.

The title complex, [Cu(C17H13N2O2)2], crystallizes with two independent mol­ecules in the asymmetric unit. Each CuII atom has a distorted ocahedral coordination environment defined by two N atoms and four O atoms from two tridentate 1-[(E)-(2-meth­oxy­phen­yl)diazen­yl]naphthalen-2-olate ligands. In the crystal, the two mol­ecules are linked via weak C—H⋯O hydrogen bonds which in turn stack parallel to [010]. A region of disordered electron density, most probably disordered methanol solvent molecules, was corrected for using the SQUEEZE routine in PLATON [Spek (2015). Acta Cryst. C71, 9–18]. Their formula mass and unit-cell characteristics were not taken into account during refinement.

Crystal structure of a helical silver(I) coordination polymer based on an unsymmetrical dipyridyl ligand: catena-poly[[silver(I)-μ-N-(pyridin-4-ylmeth-yl)pyridine-3-amine-κ (2) N:N'] tetra-fluorido-borate methanol hemisolvate

The asymmetric unit of the title compound, {[AgL]·BF4·0.5CH3OH} n , L = N-(pyridin-4-ylmeth-yl)pyridine-3-amine, C11H11N3, contains one Ag(I) ion, one ligand L, one tetra-fluorido-borate anion disordered over two orientations in a 0.669 (13):0.331 (13) ratio and one half of a methanol solvent mol-ecule situated on an inversion center. Each Ag(I) ion is coordinated by two N atoms from two L ligands in a distorted linear geometry [N-Ag-N = 174.70 (19)°]. Each L ligand bridges two Ag(I) ions, thus forming polymeric helical chains propagating in [010]. In the crystal, Ag⋯Ag [3.3369 (10) Å] and π-π inter-actions between the aromatic rings [centroid-to-centroid distance = 3.676 (4) Å] link these chains into layers parallel to (10-1). Ag⋯F and weak N(C)-H⋯F inter-actions further consolidate the crystal packing.

Crystal structure of tetra-kis-(1-oxidopyridin-2-yl)methane methanol tetra-solvate.

The asymmetric unit of the title compound, C21H16N4O4·4CH3OH, consists of a quarter mol­ecule of tetra­kis­(1-oxidopyridin-2-yl)methane and one methanol solvent mol­ecule. In the crystal, the pyridine N-oxide derivative is located about a fourfold rotoinversion axis and exhibits S 4 symmetry along the c axis. An inter­molecular O—H⋯O hydrogen bond is observed between the O atom of the pyridine N-oxide and the OH group of the methanol. An inter­molecular C—H⋯O bond is also observed between adjacent pyridine N-oxide rings.

Structure and spectroscopic properties of N,S-coordinating 2-methyl-sulfanyl-N-[(1H-pyrrol-2-yl)methyl-idene]aniline methanol monosolvate.

The reaction of pyrrole-2-carboxaldehyde and 2-(methyl-sulfan-yl)aniline in refluxing methanol gave an olive-green residue in which yellow crystals of the title compound, C12H12N2S·CH3OH, were grown from slow evaporation of methanol at 263 K. In the crystal, hydrogen-bonding inter-actions link the aniline mol-ecule and a nearby methanol solvent mol-ecule. These units are linked by a pair of weak C-H⋯Omethanol interactions, forming inversion dimers consisting of two main molecules and two solvent molecules.

Crystal structure of [N,N'-bis-(4-methyl-phen-yl)-1,2-di-phenyl-ethane-1,2-di-imine-κ(2) N,N']di-chlorido-palladium(II) methanol monosolvate.

The title compound, [PdCl2(C28H24N2)]·CH3OH, was pre­pared from the reaction of PdCl2(DMSO)2 (DMSO is di­methyl sulfoxide) and N,N′-bis­(4-methyl­phen­yl)-1,2-di­phenyl­ethane-1,2-di­imine in methanol. The chelating di­imine core of the title compound deviates slightly from planarity, with an N—C—C—N torsion angle of 5.3 (3)°. Delocalization in the di­imine core is indicated by N—C and C—C bonds that are, respectively, longer and shorter than those found in related nonchelating di­imines. The distorted square-planar coordination environment around the PdII atom is manifested as bond angles that are smaller and larger than 90°, and palladacycle torsion angles of −173.22 (16) and 167.06 (16)°. These deviations are attributed to the small bite angle of 79.13 (8)° of the di­imine chelate. The crystal packing exhibits weak inter­molecular hydrogen-bonding inter­actions involving aromatic H atoms, Cl atoms and inter­calated methanol solvent mol­ecules, defining layers parallel to (010).