Structural, spectroscopic, magnetic and electrochemical studies of monomer N-substituted-sulfanilamide copper (II) complex with 2,2'-bipyridine

A novel copper (II) complex of sulfamethazine (4-amino-N-[4,6-dimethyl-2-pyrimidinyl] benzene sulfonamide, Hsmz) ([Cu(smz)2bipy]⋅0.8H2O; bipy: 2,2'-bipyridine) has been synthesized and characterized by single crystal X-ray diffraction, EPR, IR, UV-vis and electrochemical methods. The single crystal X-ray analysis indicated that the compound crystallizes in the monoclinic space group P21/c with Z=4. The central copper (II) ion is coordinated by two bidentate sulfamethazine anions through the nitrogen atoms together with one bidentate 2,2'-bipyridine ligand forming the octahedral geometry. The characteristic vibration bands support the X-ray analysis results. The EPR spectral analysis has led to that the ground state wave function of the unpaired electron of copper ion is [Formula: see text] ((2)B1g state) and also indicated that the metal ions are located in distorted octahedral sites (D4h) elongated along the z-axis. The electrochemical studies of the complex were also carried out to determine the active sites of the ligands. The cyclic and square wave voltammetric techniques have been used to determine the complex.

Synthesis, structural and electrochemical properties of nickel(II) sulfamethazine complex with diethylenetriamine ligand

In this study, [Ni(dien)2]⋅smz2⋅(Hsmz: sulfamethazine and dien: diethylenetriamine) complex has been synthesized and its crystal structure has been determined by X-ray diffraction technique. The title complex crystallizes in orthorhombic system with space group Pbnb [a=8.556(5), b=16.228(5), c=28.209(5)Å, V=3917(3)Å(3) and Z=4]. The nickel(II) ion has distorted octahedral coordination geometry. The metal atom, which rides on a crystallographic center of symmetry, is coordinated by six nitrogen atoms of two dien ligands to form a discrete [Ni(dien)2](2+) unit, which captures two sulfamethazine ions, each through intermolecular hydrogen bonds. The powder EPR spectrum of Cu(2+) doped Ni(II) complex was recorded at room temperature. The vibrational investigation has been carried out by considering the characteristic bands related to the functional groups of the complex. The electrochemical behavior of Ni(II) ions in the presence and in the absence of smz and dien were studied by square wave and cyclic voltammetry. A well-defined irreversible peak at -1.112V different from those of the Ni(II)-smz (-0.876V) and the Ni(II)-dien complex (-1.064V) was observed in the solution containing Ni(II) ions, which was attributed to the formation of the new mixed ligand complex of Ni(II) with smz and dien.

2-Pyridinium propanol hydrogen squarate: experimental and computational study of a nonlinear optical material

The experimental and theoretical investigation of a novel organic nonlinear optical (NLO) squarate salt of 2-pyridinium propanol hydrogen squarate (1), C8H12ON(+)·C4HO4(-), were reported in this study. The crystal structure of the title compound was found to crystallize in the triclinic P-1 space group. In the asymmetric unit each squaric acid molecules have donated one H atom to the pyridines N1 and N2 atoms of a 2-pyridine propanol molecule, forming the salt (1). The X-ray analysis clearly indicated that the crystal packing has shown the hydrogen bonding ring pattern of D2(2)(10) (α-dimer) through N-H⋯O interactions. The structural and vibrational properties of the compound were also studied by computational methods of ab initio performed on the compound at DFT/B3LYP/6-31++G(d,p) (2) and HF/6-31++G(d,p) (3) level of theory. The calculation results on the basis of two models for both the optimized molecular structure and vibrational properties for the 1 are presented and compared with the X-ray analysis result. The molecular electrostatic potential (MEP), electronic absorption spectra, frontier molecular orbitals (FMOs), conformational flexibility and non-linear optical properties (NLO) of the title compound were also studied at the 2 level and the results are reported. In order to evaluate the suitability for NLO applications thermal analysis (TG, DTA and DTG) data of 1 were also obtained.

Effect of verapamil and lidocaine on TRPM and NaV1.9 gene expressions in renal ischemia-reperfusion

BACKGROUND

To determine effects on calcium and sodium channels of Ca(2+) and Na(+) channel blockers in the present study, expression levels of TRPM1, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8, and NaV1.9 genes were evaluated in kidney tissues after induced ischemia-reperfusion.

MATERIAL AND METHODS

Forty albino Wistar male rats were equally divided into 4 groups as follows: group I: control group (n = 10), group II: ischemia group (60 minutes of ischemia + 48 hours of reperfusion; n = 10), group III: ischemia (60 minutes of ischemia + 48 hours of reperfusion) + calcium channel blocker (n = 8), group IV: ischemia (60 minutes of ischemia + 48 hours of reperfusion) + sodium channel blocker (n = 8).

RESULTS

When compared to ischemia group expression levels of TRPM2, TRPM4, TRPM6, and NaV1.9 in Ca(2+) and Na(+) channel blocker groups were increased, whereas that of TRPM7 was decreased. However, expression levels of TRPM1, TRPM3, TRPM5, and TRPM8 were not determined in kidney tissue. Histologically, the Ca(2+) channel blocker verapamil and the Na(+) channel blocker lidocaine inhibited the cell death in kidney tissue compared to control.

CONCLUSION

Our study suggested that verapamil and lidocaine significantly reduce the degree of ischemia-reperfusion injury due to effects to TRPM and Nav1.9 genes.

Synthesis, an experimental and quantum chemical computational study: proton sharing in 4-Morpholinium bis(hydrogen squarate)

The experimental and theoretical investigation results of a novel organic squarate salt of 4-Morpholinium bis(hydrogen squarate) (1), C₆H₁₄ON(+)·C₈H₃O₈(-), were reported in this study. The crystal structure of the title compound was found to crystallize in the triclinic P-1 space group. In the crystals of 1 the morpholine ring adopts the chair conformation with the ethyl group in the equatorial and hydrogen atoms in axial positions. The hydrogen squarate anions are linked into a homoconjugated anion, [(HSQ)₂H], by a short symmetric, nonlinear O₈⋯H₂⋯O₂ hydrogen bond of 2.444 (2)Å. The structural and vibrational properties of the compound were also studied by computational methods of ab-initio performed on the compound at DFT/B3LYP/6-31++G(d,p) (2) and HF/6-31++G(d,p) (3) level of theory. The obtained calculation results on the basis of two models for both the optimized molecular structure and vibrational properties for the 1 obtained are presented and compared with the X-ray analysis result. On the other hand the molecular electrostatic potential (MEP), electronic absorption spectra, frontier molecular orbitals (FMOs), conformational flexibility and non-linear optical properties (NLO) of the title compound were also studied at the 2 level and the results are reported. In order to evaluate the suitability for NLO applications thermal analysis (TG, DTA and DTG) data of 1 were also obtained.

Macrocyclic Cu(ii)-organophosphonate building block with room temperature magnetic ordering

A novel macrocyclic Cu(ii)-organophosphonate building block displaying high temperature magnetic ordering, and the structure of [{Cu(2,2′-bpy)}₂(HO₃P(CH₂)₈PO₃H₂)₄] (1).

Amine grafted silica supported CrAuPd alloy nanoparticles: superb heterogeneous catalysts for the room temperature dehydrogenation of formic acid

The CrAuPd/N-SiO₂ catalyst generates H₂ from formic acid solution with unprecedented activity even at room temperature and in the absence of additives.

Synthesis, an experimental and quantum chemical computational study of a new nonlinear optical material: 2-picolinium hydrogensquarate

The experimental and theoretical investigation results of a novel organic non-linear optical (NLO) organic squarate salt of 2-Picolinium hydrogensquarate (1), C6H8N+·C4HO4-, were reported in this study. The space group of the title compound was found in the monoclinic C2/c space group. It was found that the asymmetric unit consists of one monohydrogen squarate anion together with mono protonated 2-Picolinium, forming the (1) salt. The X-ray analysis clearly indicated that the crystal packing has shown the hydrogen bonding ring pattern of D2(2)(10) (α-dimer) through NH⋯O interactions. The hydrogensquarate anions form α-dimer, while 2-Picolinium molecule interacts through NH⋯O and CH⋯O with the hydrogensquarate anion. The structural and vibrational properties of the compound were also studied by computational methods of ab initio performed on the compound at DFT/B3LYP/6-31++G(d,p) (2) and HF/6-31++G(d,p) (3) level of theory. The calculation results on the basis of two models for both the optimized molecular structure and vibrational properties for the 1 obtained are presented and compared with the X-ray analysis result. On the other the molecular electrostatic potential (MEP), electronic absorption spectra, frontier molecular orbitals (FMOs), conformational flexibility and non-linear optical properties (NLO) of the title compound were also studied at the 2 level and the results are reported. In order to evaluate the suitability for NLO applications thermal analysis (TG, DTA and DTG) data of 1 were also obtained.

EPR Studies of VO2+ in Ba(ClO4) 2 ・3H2O Single Crystals

The results of an electron paramagnetic resonance (EPR) study of vanadyl ion VO2+ doped in single crystals of Ba(ClO4)2 - 3 H2O are reported. The spectra indicated the presence of two substitutional and interstitial sites depending on the orientation. The spin-Hamiltonian parameters were determined from single crystal and powder EPR data. These parameters were found to be axial symmetric for the powder sample, whereas they showed deviations from axial symmetry for the single crystal

EPR Studies of Cu2+ in dl-Aspartic Acid Single Crystals

EPR studies of Cu2+ doped dl-Aspartic Acid [NH2CH(CH2COOH)COO] powder and single crystal have been carried out at 113 and 300 K. The principal hyperfine and g values, covalancy parameter, mixing coefficients and Fermi-contact term of the complex were obtained, and the ground-state wavefuntion of the Cu2+ ion in the lattice has been constructed.

Synthesis, Crystal Structure, Spectral and Thermal Characterization of cis-Diaquabis(1,10-phenanthroline)zinc(II) Diorotate Hydrate, cis-[Zn(H2O)2(phen)2](H2Or)2 · (H2O)2.125

Preparation, X-ray crystal structure, thermal behavior, and IR spectroscopic studies of cis-diaquabis(1,10-phenanthroline)zinc(II) diorotate hydrate are described. In the compound [Zn(H2O)2(C12H8N2)2](C5H3N2O4)2·(H2O)2.125 (1), the zinc ion, located on a twofold axis, is coordinated by two aqua ligands together with a pair of bidentate 1,10-phenanthroline (phen) molecules, and exhibits a distorted octahedral coordination. The orotate anions have a single negative charge each. The metal−coordinated water molecules link the orotate ions to the metal complex via O-H· · ·O hydrogen bonds. Also the uncoordinated water molecules are bonded to orotate ions through O-H· · ·O hydrogen bonds. Thus, an extensive network of hydrogen bonds together with π-π, and π-ring interactions stabilize the crystal structure and form an infinitive three dimensional structure. The thermal decomposition pathway of 1 has been investigated by the help of thermal analysis data (TG, DTG and DTA).

Crystal Structure, Spectroscopic and Redox Properties of Copper(II) Bis{2-[(2,6-dimethylphenyl)iminomethyl-3-methoxyphenolate]}

The coordination chemistry of N-(2,6-di-methylphenyl)-2-hydroxy-3-methoxybenzaldimine (1) with Cu(II) has been investigated by X-ray crystallography, electronic and EPR spectroscopies, as well as by electro- and magnetochemistry. The title complex 2 crystallizes in the orthorhombic space group P212121 (a = 8.1538, b = 17.7466, c =19.8507 Å). The mononuclear square-planar molecules 2 featuring trans-N2O2 coordination are connected via weak intermolecular C-H· · ·π interactions into infinite chains parallel to the a axis. Although the intermolecular Cu· · ·Cu separations within individual chains and between chains are very long (8.154 and 9.726 Å ), the exchange interaction parameter G = 2.03 < 4, estimated from solid state EPR spectra, suggests the existence of long-distance superexchange pathways between adjacent Cu(II) centers. The electronic and electrochemical features of the compound are also discussed.

Structural, spectroscopic and voltammetric studies of bis(acetazolamido)bis(aquo)bis(nicotinamide)copper(II)

Polymeric copper(II) complex, [Cu(Hacm)(2)(na)(2)(H(2)O)(2)] [H(2)acm; acetazolamide, na; nicotinamide] was synthesized and characterized by spectroscopic (IR; infrared spectroscopy, EPR; electron paramagnetic resonance), structural (XRD) and voltammetric structural (CV) methods. The copper(II) compound crystallizes in the triclinic space group P1¯, Z=1, with the unit-cell dimensions: a=7.672 (5)Å, b=8.681 (5)Å, c=11.938 (5)Å, α=90.807 (7)°, β=98.616 (5)° and γ=110.647 (5)°. The Cu(II) ion has a distorted octahedral coordination geometry. The crystal packing of the complex is stabilized by intermolecular O-H…O and N-H…O hydrogen bonds. The powder EPR spectrum of copper(II) complex have indicate that the paramagnetic center is in a tetragonal symmetry with the Cu(2+) ion having a distorted octahedral geometry. The vibrational investigation has been carried out on the basis of some characteristic IR bands of acetazolamide and nicotinamide molecules.

Structural characterization and EPR spectral studies on mononuclear copper(II) complex of saccharin with ethylnicotinate

Mononuclear copper(II) saccharinate (sac) complex containing ethylnicotinate (enc), [Cu(enc)(2)(sac)(2)(H(2)O)].1.4H(2)O has been synthesized and characterized by spectroscopic (IR, UV-vis, EPR), X-ray diffraction technique and electrochemical methods. It crystallizes in the tetragonal crystal systems with space group I4(1)cd and Z=8. The copper(II) ion presents a CuN(4)O distorted square pyramidal coordination. Based on EPR and optical absorption studies, spin-Hamiltonian and bonding parameters have been calculated. The g-values, calculated for title complex in polycrystalline state at 298 K and in frozen DMF (110K), indicate the presence of the unpaired electron in the d(x)(2)-(y)(2) orbital. The evaluated metal-ligand bonding parameters showed strong in-plane sigma and in-plane pi-bonding. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed. The cyclic voltammogram of the title complex investigated in DMF (dimethylformamide) solution exhibits only metal centred electroactivity in the potential range +/-1.25 V vs. Ag/AgCl reference electrode.

Crystal structure and EPR studies of mixed ligand complex of cobalt(II) with saccharin and ethylisonicotine

The tetraaquabis(ethylisonicotinate)cobalt(II) disaccharinate, [Co(ein)2(H2O)4].(sac)2, (CENS), (ein: ethylisonicotinate and sac: saccharinate) complex has been synthesized and its crystal structure has been determined by X-ray diffraction analysis. The title complex crystallizes in monoclinic system with space group P2(1)/c and Z=2. The Co(II) cations present a slightly distorted CoN2O4 octahedral environment, with equatorially coordinated water molecules and axially pyridine N-bound ethylisonicotinate ligands. The magnetic environments of Cu2+-doped Co(II) complex have been identified by electron paramagnetic resonance (EPR) technique. Cu2+-doped CENS single crystals have been studied at room temperature in three mutually perpendicular planes. The calculated results of the Cu2+-doped CENS indicate that Cu2+ ion substitute with the Co2+ ion in the host lattice. The angular variations of the EPR spectra have shown that two different Cu2+ complexes are located in different chemical environments, and each environment contains two magnetically inequivalent Cu2+sites in distinct orientations occupying substitutional positions in the lattice and show very high angular dependence. The cyclic voltammogram of the title complex investigated in dimethylformamide (DMF) solution exhibits only metal centered electroactivity in the potential range -1.0-1.25V versus Ag/AgCl reference electrode.

Synthesis, spectroscopy, X-ray structure and redox behaviors of 4-(N-R-salicylideneimine)-2,6-diphenylphenols

A series of sterically hindered 4-(N-R-salicylaldimine)-2,6-diphenylphenols (X), where R=H (1), 3-CH3 (2), 5-CH3 (3), 3-OCH3 (4), 4-OCH3 (5), 5-OCH3 (6), 3-tBu (7), 5-tBu (8), 3,5-tBu2(9) and 5,6-benzo(10), were synthesized and their structure as well as redox behavior studied by analytical, spectroscopic [1H, (13C) NMR, IR, UV-vis and mass spectrometry] and cyclic voltammetric (CV) techniques. Single crystal X-ray diffraction studies of 7 evidenced its existence as non-planar enol-imine tautomer structure, in which the phenol ring of the molecule is twisted around C-N single bond by 21.5(2) degrees. The packing structure of 7 is stabilized by C-H...pi(Ph) and O...O and C...O intermolecular short contact interactions. The CV of X display rate is dependent on irreversible and quasi-reversible redox waves in the anodic and cathodic regions due to oxidation and reduction of phenolic and iminic groups, respectively. As evidenced by ESR and UV-vis study, chemical oxidation of X by PbO2 and (NH4)2Ce(NO3)6 in MeCN and CHCl3 generates stable phenoxyl radicals [(g approximately 2.005 and lambda approximately 450 nm (1600-8200 M(-1) cm(-1))].

Synthesis, spectroscopic and structural studies of new Schiff bases prepared from 3,5-Bu2t-salicylaldehyde and heterocyclic amines: X-ray structure of N-(3,5-di-tert-butylsalicylidene)-1-ethylcarboxylato-4-aminopiperidine

Two new sterically hindered salicylaldimines, N-(2,2,6,6-tetramethyl-piperidine-4)-3,5-Bu2t-salicylaldimine (I) and N-(1-carboxyethyl piperidine-4)-3,5-Bu2t-salicylaldimine (II), have been prepared and characterized by IR, UV-vis, 1H NMR, 13C NMR techniques and the structure of II has been examined by X-ray crystallography. No intermolecular H-bonding, pi-pi stacking or C--H...pi interactions are observed in the structure. The crystal structure the was mainly governed by intermolecular steric repulsions, due to bulky tert-butyl groups and the tendency of salicylaldimine rings to pack in parallel mode forms one-dimensional columns.