One-pot synthesis of a new 2-substituted 1,2,3-triazole 1-oxide derivative from dipyridyl ketone and isonitrosoacetophenone hydrazone: Nickel(II) complex, DNA binding and cleavage properties.

An efficient and simple one-pot synthesis of a new 1,2,3-triazole-1-oxide via reaction between isonitrosoacetophenone hydrazone and dipyridyl ketone in the EtOH/AcOH at room temperature has been developed smoothly in high yield. The reaction proceeds via metal salt free, in-situ formation of asymmetric azine followed by cyclization to provide 1,2,3-triazole 1-oxide compound. It has been structurally characterized. The 1:1 ratio reaction of the 1,2,3-triazole 1-oxide ligand with nickel(II) chloride gives the mononuclear complex [Ni(L)(DMF)Cl2], hexa-coordinated within an octahedral geometry. Characterization of the 1,2,3-triazole compound and its Ni(II) complex with FTIR, 1H and 13C NMR, UV-vis and elemental analysis also confirms the proposed structures of the compounds. The interactions of the compounds with Calf thymus DNA (CT-DNA) have been investigated by UV-visible spectra and viscosity measurements. The results suggested that both ligand and Ni(II) complex bind to DNA in electrostatic interaction and/or groove binding, also with a slight partial intercalation in the case of ligand. DNA cleavage experiments have been also investigated by agarose gel electrophoresis in the presence and absence of an oxidative agent (H2O2). Both 1,2,3-triazole 1-oxide ligand and its nickel(II) complex show nuclease activity in the presence of hydrogen peroxide. DNA binding and cleavage affinities of the 1,2,3-triazole 1-oxide ligand is stronger than that of the Ni(II) complex.

(4,9-Dimethyl-9H-carbazol-3-yl)meth-anol.

In the title compound, C15H15NO, the carbazole skeleton includes a methanol group at the 3-position. The indole ring system is almost planar [maximum deviation = 0.045 (2) Å]. In the crystal, O-H⋯O hydrogen bonds link the mol-ecules into zigzag chains along the b-axis direction. There are weak C-H⋯π inter-actions within the chains and linking neighbouring chains forming sheets lying parallel to (001).

catena-Poly[[aqua-bis-(4-formyl-benzoato-κ(2) O (1),O (1'))cadmium]-µ-pyrazine-κ(2) N:N'].

The polymeric title compound, [Cd(C8H5O3)2(C4H4N2)(H2O)] n , contains two 4-formyl-benzoate (FB) anions, one pyrazine mol-ecule and one coordinating water mol-ecule; the FB anions act as bidentate ligands. The O atom, the aldehyde H atom and the benzene ring of one of the FB anions are disordered over two positions. The O atoms were freely refined [refined occupancy ratio 0.79 (2):0.21 (2)], while the aldehyde H atoms and the benzene ring atoms were refined with fixed occupancy ratios of 0.8:0.2 and 0.5:0.5, respectively. In the ordered FB anion, the carboxyl-ate group is twisted away from the attached benzene ring (A) by 22.7 (8)°. In the disordered FB anion, the corresponding angles are 15.6 (10) and 11.4 (11)° for rings B and B', respectively. Benzene rings A and B are oriented at a dihedral angle of 24.2 (7), A and B' at 43.0 (8)°. The pyrazine ring makes dihedral angles of 67.5 (4), 89.6 (7) and 86.2 (7)°, respectively, with benzene rings A, B and B'. The pyrazine ligands bridge the Cd(II) cations, forming polymeric chains running along the b-axis direction. In the crystal, O-Hwater ⋯ Ocarboxyl-ate hydrogen bonds link adjacent chains into layers parallel to the bc plane. These layers are linked via C-Hpyrazine ⋯ Oform-yl hydrogen bonds, forming a three-dimensional network. π-π interactions [centroid-centroid distances = 3.870 (11)-3.951 (5) Å] further stabilize the crystal structure. There is also a weak C-H⋯π inter-action present.

catena-Poly[[di-aqua-bis-(4-formyl-benzo-ato-κO (1))nickel(II)]-µ-pyrazine-κ(2) N:N'].

In the title polymeric compound, [Ni(C8H5O3)2(C4H4N2)(H2O)2] n , the Ni(II) atom is located on a twofold rotation axis and has a slightly distorted octa-hedral coordination sphere. In the equatorial plane, it is coordinated by two carboxyl-ate O atoms of two symmetry-related monodentate formyl-benzoate anions and by two N atoms of the bridging pyrazine ligand, which is bis-ected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water mol-ecules. In the formyl-benzoate anion, the carboxyl-ate group is twisted away from the attached benzene ring by 7.0 (6)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 66.2 (3)°. The pyrazine ligands bridge the Ni(II) cations, forming polymeric chains running along the b-axis direction. Intra-molecular O-H⋯O hydrogen bonds link the water ligands to the carboxyl-ate O atoms. In the crystal, water-water O-H⋯O hydrogen bonds link adjacent chains into layers parallel to the bc plane. Pyrazine-formyl C-H⋯O hydrogen bonds link the layers, forming a three-dimensional network. There are also weak C-H⋯π inter-actions present. The title compound is isotypic with the copper(II) complex [Çelik et al. (2014a). Acta Cryst. E70, m4-m5].

Ethyl 4,9-dimethyl-9H-carbazole-3-carboxyl-ate.

In the title compound, C17H17NO2, the carbazole skeleton includes an eth-oxy-carbonyl group at the 3-position. The indole three-ring system is almost planar [maximum deviation = 0.065 (2) Å], and the ethyl ester group is inclined to its mean plane by 15.48 (2)°. In the crystal, there are π-π stacking inter-actions between parallel benzene rings and between parallel benzene and pyrrole rings of adjacent mol-ecules [centroid-centroid distances = 3.9473 (8) and 3.7758 (8) Å, respectively]. Weak C-H⋯π inter-actions are also present.

catena-Poly[[di-aqua-bis-(4-formyl-benzoato-κO (1))copper(II)]-µ-pyrazine-κ(2) N:N'].

In the title polymeric compound, [Cu(C8H5O3)2(C4H4N2)(H2O)2] n , the Cu(II) atom is located on a twofold rotation axis and has a slightly distorted octa-hedral coordination sphere. In the equatorial plane, it is coordinated by two carboxyl-ate O atoms of two symmetry-related monodentate formyl-benzoate anions and by two N atoms of the bridging pyrazine ligand, which is bis-ected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water mol-ecules. In the formyl-benzoate anion, the carboxyl-ate group is twisted away from the attached benzene ring by 6.2 (2)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 68.91 (8)°. The pyrazine ligands bridge the Cu(II) cations, forming polymeric chains running along the b-axis direction. Strong intra-molecular O-H⋯O hydrogen bonds link the water mol-ecules to the carboxyl-ate O atoms. In the crystal, O-Hwater⋯Owater hydrogen bonds link adjacent chains into layers parallel to the bc plane. The layers are linked via C-Hpyrazine⋯Oform-yl hydrogen bonds, forming a three-dimensional network. There are also weak C-H⋯π inter-actions present.

Di-aqua-bis-(3-chloro-benzoato-κO)bis-(nicotinamide-κN (1))cobalt(II).

In the title complex, [Co(C7H4ClO2)2(C6H6N2O)2(H2O)2], the Co(II) atom is located on an inversion center and is coordinated by two 3-chloro-benzoate (CB) anions, two nicotinamide (NA) ligands and two water mol-ecules. The four O atoms in the equatorial plane form a slightly distorted square-planar arrangement, while the slightly distorted octa-hedral coordination is completed by the two N atoms of the NA ligands in the axial positions. The dihedral angle between the carboxyl-ate group and the adjacent benzene ring is 9.14 (9)°, while the pyridine and benzene rings are oriented at a dihedral angle of 82.18 (8)°. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the mol-ecules into a two-dimensional network lying parallel to (101). π-π stacking between parallel pyridine rings of adjacent mol-ecules [centroid-centroid distance = 3.7765 (8) Å] further stabilizes the crystal structure.

Bis(3-chloro-benzoato-κ(2) O,O')bis-(nicotinamide-κN)copper(II).

The mol-ecule of the title Cu(II) complex, [Cu(C7H4ClO2)2(C6H6N2O)2], contains two 3-chloro-benzoate (CB) and two nicotinamide (NA) ligands; the CB act as bidentate ligands, while the NA are monodentate ligands. The resulting CuN2O4 coordination polyhedron is a considerably distorted octahedron. The dihedral angles between the carboxyl-ate groups and the adjacent benzene rings are 17.92 (12) and 24.69 (16)°, while the two benzene rings and the two pyridine rings are oriented at dihedral angles of 52.20 (8) and 1.56 (6)°. In the crystal, N-H⋯N and C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. The π-π contact between the benzene rings [centroid-centroid distance = 3.982 (2) Å] may further stabilize the crystal structure.

catena-Poly[aqua-bis-(µ-3-chloro-benzo-ato-κ(2) O:O')zinc].

In the polymeric title compound, [Zn(C7H4ClO2)2(H2O)] n , the Zn(II) cation is located on a twofold rotation axis and is coordinated by carboxylate O atoms of four monodentate chloro-benzoate anions and by one water mol-ecule, located on a twofold rotation axis, in a distorted square-pyramidal geometry. In the anion, the carboxyl-ate group is twisted away from the attached benzene ring by 44.16 (11)°. The chloro-benzoate anion bridges Zn(II) cations, forming polymeric chains running along the c-axis direction. O-H⋯O hydrogen bonds between coordinating water mol-ecules and carboxyl-ate groups link adjacent chains into layers parallel to the bc plane.

Di-µ-nicotinamide-κ(2) N (1):O;κ(2) O:N (1)-bis-[aqua-bis-(3-chloro-benzoato-κ(2) O,O')cadmium].

In the centrosymmetric dinuclear title compound, [Cd2(C7H4ClO2)4(C6H6N2O)2(H2O)2], the Cd(II) atom is coord-inated by one N atom from one bridging nicotinamide ligand and one O atom from another symmetry-related bridging nicotinamide ligand, four O atoms from two 3-chloro-benzoate ligands and one water mol-ecule in an irregular geometry. The dihedral angles between the carboxyl-ate groups and the adjacent benzene rings are 6.98 (12) and 2.42 (13)°, while the benzene rings are oriented at a dihedral angle of 4.33 (6)°. Inter-molecular O-H⋯O, N-H⋯O and weak C-H⋯O hydrogen bonds link the mol-ecules into a three-dimensional network. π-π inter-actions, indicated by short centroid-centroid distances [3.892 (1) Šbetween the pyridine rings and 3.683 (1) Šbetween the benzene rings] further stabilize the structure.

4-But-oxy-N'-[1-(4-methyl-phen-yl)ethyl-idene]benzohydrazide.

The mol-ecule of the title compound, C(20)H(24)N(2)O(2), exists in a trans conformation with respect to the C=N bond. The dihedral angle between the benzene rings is 79.0 (1)°. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into chains propagating in [001]. Two weak C-H⋯O inter-actions also occur.

Crystal structure of trans-di-aqua-bis-(nicotinamide-κN (1))bis-(4-nitro-benzoato-κO)manganese(II).

The asymmetric unit of the title compound, [Mn(C7H4NO4)2(C6H6N2O)2(H2O)2], contains one Mn(II) atom, one 4-nitro-benzoate (NB) anion, one nicotinamide (NA) ligand and one water mol-ecule; NA and NB each act as a monodentate ligand. The Mn(II) atom, lying on an inversion centre, is coordinated by four O atoms and two pyridine N atoms in a distorted octa-hedral geometry. The water mol-ecules are hydrogen bonded to the carboxyl-ate O atoms. The dihedral angle between the carboxyl-ate group and the adjacent benzene ring is 24.4 (3)°, while the benzene and pyridine rings are oriented at a dihedral angle of 86.63 (11)°. In the crystal, O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules, forming a layer parallel to the ab plane. The layers are further linked via weak C-H⋯O hydrogen bonds, a π-π stacking inter-action [centroid-centroid distance = 3.868 (2) Å] and a weak C-H⋯π inter-action, resulting in a three-dimensional network.

Synthesis, structural characterization and DNA interaction of zinc complex from 2,6-diacetylpyridine dihydrazone and {4-[(2E)-2-(hydroxyimino)acetyl]phenoxy} acetic acid.

A new water soluble zinc complex has been prepared and structurally characterized. The Zn(II) complex was synthesized by the reaction of 2,6-diacetylpyridine dihydrazone (dph) with {4-[(2E)-2-(hydroxyimino)acetyl]phenoxy} acetic acid (H2L) in the presence of zinc(II) acetate. Single crystal X-ray diffraction study revealed that the zinc ion is situated in distorted trigonal-bipyramidal environment where the equatorial position is occupied by the nitrogen atom of pyridine ring and the oxygen atoms of acetate groups of two oxime ligands (H2L) whereas the axial positions of the zinc complex are occupied by the imine nitrogen atoms of dph ligand. Characterization of the complex with FTIR, (1)H and (13)C NMR, UV-vis and elemental analysis also confirmed the proposed structure. Interaction of the Zn(II) complex with calf-thymus DNA (CT-DNA) was investigated through UV-vis spectroscopy and viscosity measurements. The results suggest that the complex preferably bind to DNA through the groove binding mode. The zinc complex cleaves plasmid pBR 322 DNA in the presence and absence of an oxidative agent (H2O2), possibly through a hydrolytic pathway which is also supported by DNA cleave experiments in the presence of different radical scavengers. The nuclease activity of the zinc complex significantly depends on concentration of the complex and incubation time both in the presence and absence of H2O2. DNA cleave activity is inhibited in the presence of methyl green indicating that the zinc complex seems to bind the major groove of DNA.

Crystal structure of tetra-kis-(µ-2,4,6-tri-methyl-benzoato-κ(2) O:O')bis-[(nicotinamide-κN (1))copper(II)].

In the title binuclear Cu(II) complex, [Cu2(C10H11O2)4(C6H6N2O)2], the two Cu(II) cations [Cu⋯Cu = 2.5990 (5) Å] are bridged by four 2,4,6-tri-methyl-benzoate (TMB) anions. The four nearest O atoms around each Cu(II) cation form distorted square-planar arrangements and the distorted square-pyramidal coordinations are completed by the pyridine N atoms of nicotinamide mol-ecules at distances of 2.164 (2) and 2.165 (2) Å, respectively. The Cu(II) cations are displaced by -0.2045 (3) and 0.2029 (3) Šfrom the corresponding planes formed by the nearest four O atoms. In the mol-ecule, the dihedral angles between the planes of the benzene rings and the adjacent carboxyl-ate groups are 80.6 (2), 51.4 (2), 24.4 (2) and 32.5 (2)°, while the planes of the pyridine rings are oriented at a dihedral angle of 11.28 (10)°. In the crystal, bifurcated N-H⋯O and weak C-H⋯O hydrogen bonds link the mol-ecules, enclosing R 2 (2)(8) and R 4 (4)(8) ring motifs, into a three-dimensional network. The structure contains a solvent-accessible void of 72 Å(3), but there is no solvent mol-ecule located within this void. The crystal studied was an inversion twin refined with a minor component of 0.488 (8).

Crystal structure of catena-poly[[di-aqua-bis-(4-formyl-benzoato-κO (1))cobalt(II)]-µ-pyrazine-κ(2) N:N'].

In the title polymeric compound, [Co(C8H5O3)2(C4H4N2)(H2O)2] n , the Co(II) atom is located on a twofold rotation axis and has a slightly distorted octa-hedral coordination sphere. In the equatorial plane, it is coordinated by two carboxyl-ate O atoms of two symmetry-related monodentate formyl-benzoate anions and by two N atoms of two bridging pyrazine ligands. The latter are bis-ected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water mol-ecules. In the formyl-benzoate anion, the carboxyl-ate group is twisted away from the attached benzene ring by 7.50 (8)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 64.90 (4)°. The pyrazine ligands bridge the Co(II) cations, forming linear chains running along the b-axis direction. Strong intra-molecular O-H⋯O hydrogen bonds link the water mol-ecules to the carboxyl-ate O atoms. In the crystal, weak O-Hwater⋯Owater hydrogen bonds link adjacent chains into layers parallel to the bc plane. The layers are linked via C-Hpyrazine⋯Oform-yl hydrogen bonds, forming a three-dimensional network. There are also weak C-H⋯π inter-actions present.

Crystal structure of catena-poly[[aqua-bis-(4-formyl-benzoato)-κ(2) O (1),O (1');κO (1)-zinc]-µ-pyrazine-κ(2) N:N'].

The asymmetric unit of the title polymeric compound, [Zn(C8H5O3)2(C4H4N2)(H2O)] n , contains two mol-ecular units. Each unit comprises two 4-formyl-benzoate (FB) anions, one pyrazine mol-ecule and one coordinating water mol-ecule; the FB anions act either as bidentate or as monodentate ligands. The O atoms of the bidentately coordinating FB anions are disordered over two positions, and they were refined with fixed occupancy ratios of 0.75:0.25 and 0.70:0.30, respectively. In the ordered monodentately coordinating FB anions, the carboxyl-ate groups are twisted away from the attached benzene rings (B and E) by 12.1 (2) and 9.2 (2)°, respectively. In the disordered FB anions, the corresponding angles are 14.1 (1) and 4.0 (2)° for benzene rings A and D, respectively. Benzene rings A and B are oriented at a dihedral angle of 45.7 (1)°, D and E at 23.2 (1)°. Pyrazine ring C makes dihedral angles of 85.6 (1) and 72.7 (1)°, respectively, with benzene rings A and B, and pyrazine ring F makes dihedral angles of 87.0 (1) and 81.3 (1)° with benzene rings D and E, respectively. The pyrazine ligands bridge the Zn(II) cations, forming polymeric chains running parallel to the b-axis direction. Medium-strength intra-molecular O-H⋯O hydrogen bonds link the water mol-ecules to the carboxyl-ate O atoms. In the crystal, water-carboxyl-ate O-H⋯O hydrogen bonds link adjacent chains into layers parallel to the bc plane. The layers are linked via weak pyrazine-formyl C-H⋯O and form-yl-carboxyl-ate C-H⋯O hydrogen bonds. π-π contacts between the benzene rings, with centroid-to-centroid distances of 3.7765 (16), 3.7905 (15) and 3.8231 (16) Å, may further stabilize the structure. There are also weak C-H⋯π inter-actions present.

Crystal structure of poly[bis-(µ-nicotinamide-κ(2) N (1):O)bis-(µ-4-nitro-benzoato-κ(2) O (1):O (1'))zinc].

The asymmetric unit of the title coordination polymer, [Zn(C7H4NO4)2(C6H6N2O)2] n , contains two 4-nitro-benzoate (NB) anions and two nicotinamide (NA) ligands. The Zn(II) atom has a slightly distorted octa-hedral coordination sphere. In the equatorial plane, it is coordinated by three carboxyl-ate O atoms of the NB anions and one O atom of one of the two NA ligands. The axial positions are occupied by the pyridine N atoms of the two NA ligands. In the two NB anions, the carboxyl-ate groups are twisted away from the attached benzene rings by 13.8 (2) and 13.4 (2)°, while the benzene rings are oriented at a dihedral angle of 11.5 (2)°. The dihedral angle between the NA rings is 10.3 (1)°. Only one of the two NB anions and one of the two NA ligands bridge adjacent Zn(II) ions through eight- and twelve-membered rings, respectively, forming polymeric chains running along the a-axis direction. In the crystal, N-H ⋯ O hydrogen bonds link adjacent chains, enclosing R(16), R 2 (2)(20) and R 6 (6)(16) ring motifs, forming layers parallel to (01-1). The layers are linked via a number of C-H⋯O hydrogen bonds, forming a three-dimensional network.

DFT calculations, spectroscopy and antioxidant activity studies on (E)-2-nitro-4-[(phenylimino)methyl]phenol.

We have reported synthesis and characterization of (E)-2-nitro-4-[(phenylimino)methyl]phenol by using X-ray crystallographic method, FT-IR and UV-vis spectroscopies and density functional theory (DFT). Optimized geometry and vibrational frequencies of the title compound in the ground state have been computed by using B3LYP with the 6-311G+(d,p) basis set. HOMO-LUMO energy gap, Non-linear optical properties and NBO analysis of the compound are performed at B3LYP/6-311G+(d,p) level. Additionally, as remarkable properties, antioxidant activity of the title compound (CMPD) has been determined by using different antioxidant test methods i.e. ferric reducing antioxidant power (FRAP), hydrogen peroxide scavenging (HPSA), free radical scavenging (FRSA) and ferrous ion chelating activities (FICA). When compared with standards (BHA, BHT, and α-tocopherol), we have concluded that CPMD has effective FRAP, HPSA, FRSA and FICA.

Comparative experimental and theoretical studies of N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine novel Schiff base.

In this work, N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine, C15H14N2O2, Schiff base molecule has been synthesized and characterized by elemental analyses, UV-Vis and IR spectroscopy and single crystal X-ray determination. The molecule of the title compound adopt an E configuration about the azomethine CN double bond. The benzene and phenyl rings are planar and the dihedral angle between the planes is 7.2(2)°. The crystal structure is stabilized by intermolecular OH⋯O and intramoleculer NH⋯O hydrogen bonding interactions. X-ray diffraction analyses show that, N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine Schiff base molecule crystallizes in the monoclinic system, P21/c space group, a=4.392(5)Å, b=22.340(5)Å, c=13.528(5)Å, ß=92.882(5)°, V=1325.7(16)Å(3), Z=4. The conformational analysis of N-(4-Methylbenzylidene)-N'-(2-carboxyphenyl) hydrazine was performed by the density functional theory (DFT) B3LYP method using the 6-311++G(d,p) basis set. Also, theoretical values of FTIR and UV-Vis were performed by the same method. The calculated geometry parameters, IR and UV-Vis results were compared with experimental results.

Molecular structure, quantum mechanical calculation and radical scavenging activities of (E)-4,6-dibromo-2-[(3,5-dimethylphenylimino)methyl]-3-methoxyphenol and (E)-4,6-dibromo-2-[(2,6-dimethylphenylimino)methyl]-3-methoxyphenol compounds.

In this study, (E)-4,6-dibromo-2-[(3,5-dimethylphenylimino)methyl]-3-methoxyphenol and (E)-4,6-dibromo-2-[(2,6-dimethylphenylimino)methyl]-3-methoxyphenol compounds have been synthesized and characterized by using X-ray crystallographic method, FT-IR and Density functional method. The molecular geometry, vibrational frequencies of the title compounds in the ground state have been calculated by using B3LYP with the 6-31G(d,p) basis set. The tautomeric form of the compounds has been demonstrated by using single crystal X-ray method, FT-IR spectrometer and DFT method. In addition, HOMO-LUMO energy gap, molecular electrostatic potential map and NBO analysis of the compounds are performed at B3LYP/6-31G(d,p) level. It may be remarked that the free radical scavenging activities of the title compounds were assessed using DPPH, DMPD+, and ABTS+ assays. The obtained results show that especially compound 2 has effective DPPH (SC50 1.52±0.14 µg/mL), DMPD+ (SC50 1.22±0.21 µg/mL), and ABTS+ (SC50 3.32±0.17 µg/mL) scavenging activities compared with standards (BHA, rutin, and trolox).