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Graphical abstract The reactions of trans -[ Pt Cl 2 (N CR) 2 ] with pyrroline N -oxide afford arylamido platinum(II) complexes trans- [ Pt Cl 2 {(O CR)N CCH 2 CH 2 CMe 2 NH} 2 ] via one-pot reaction involving spontaneous N O bond cleavage. However, the reactions of trans -[ Pd Cl 2 (N CR) 2 ] with pyrroline N -oxide furnish Δ4-1,2,4-oxadiazoline palladium(II) complexes trans- [ Pd Cl 2 {N C(R)ONC(H)CH 2 CH 2 CMe 2 } 2 ]. Abstract The reactions of bis(organonitrile) platinum(II) complexes trans -[ Pt Cl 2 (N CR) 2 ] (R = C 6 H 4 (p -HC O), CH 2 C 6 H 4 (p -CH 3)) with pyrroline N -oxide −O+N CHCH 2 CH 2 CMe 2 afford arylamido platinum(II) complexes trans- [ Pt Cl 2 {(O CR)N CCH 2 CH 2 CMe 2 NH} 2 ] (R = C 6 H 4 (p -HC O) (1), CH 2 C 6 H 4 (p -CH 3) (2)). The spectral data of 1 and 2 show that the oxadiazoline rings in both cases have opened by a spontaneous N O bond cleavage to form (Z)- p -formyl- N -(5,5-dimethylpyrrolidin-2-ylidene)benzamide or (Z)- N -(5,5-dimethylpyrrolidin-2-ylidene)-2- p -tolylacetamide ligands, respectively, where the N -atoms of the benzamide or acetamide moieties coordinate to platinum(II) metal centre in trans positions. However, the reactions of bis(organonitrile) palladium(II) complexes trans -[ Pd Cl 2 (N CR) 2 ] with pyrroline N -oxide furnish Δ4-1,2,4-oxadiazoline palladium(II) complexes trans- [ Pd Cl 2 {N C(R)ONC(H)CH 2 CH 2 CMe 2 } 2 ] (R = C 6 H 4 (p -HC O) (3), CH 2 C 6 H 4 (p -CH 3) (4)) as the exclusive detected products. Compounds 1 – 4 have been characterized by IR, 1H, 13C NMR spectroscopy, elemental analyses, ESI+-MS and also, in the case of 1 , by single crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

The aldoximes C11H9NO (I) and C15H11NO (II), synthesized in ca 90%yield, by treatment of 1-naphthaldehyde or phenanthrene-9-carbaldehyde, respectively, with hydroxylamine hydrochloride and sodium carbonate, have been characterized by IR, ¹H, 13C and DEPT-135 NMR spectroscopies, and also by single-crystal X-ray diffraction analysis. The molecules of (I) and (II) are conformationally similar, with the aldoxime substituent groups lying outside the planes of the naphthalene or phenanthrene rings, forming dihedral angles with them of 23.9 (4) and 27.9 (6)°, respectively. The crystal structures of both (I) and (II) are similar with a single intermolecular O--H...N hydrogen-bonding interaction, giving rise to the formation of one-dimensional polymeric chains extending along the 21 (b) screw axes in each. [ABSTRACT FROM AUTHOR]

Six novel palladium(II) complexes of a thiosemicarbazone Schiff base with isatin moiety (PdL1 to PdL6) were synthesized by the reaction of palladium(II) with the following: (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L1H), (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L2H), (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L3H), (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L4H), (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L5H) and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L6H). The structures of these complexes were characterized using elemental analysis and infrared, UV–visible, 1H NMR and mass spectroscopies. The structure of PdL5 was further characterized using single-crystal X-ray diffraction. The interaction of these complexes with calf thymus DNA was characterized with a high intrinsic binding constant (Kb = 5.78 × 104 to 1.79 × 106 M−1), which reflected the intercalative activity of these complexes towards calf thymus DNA. This result was also confirmed from viscosity data. Electrophoresis studies revealed that complexes PdL1 to PdL6 could cleave DNA via an oxidative pathway in the presence of an external agent. Data obtained from an in vitro anti-proliferative study clearly established the anticancer potency of these compounds against the human colorectal carcinoma cell line HCT 116. [ABSTRACT FROM AUTHOR]

The title complex, [PdCl2(C8H14N2O)2]·2H2O, was obtained by N-O bond cleavage of the oxadiazoline rings of the trans-[dichlorido-bis(2,5,5-trimethyl-5,6,7,7a-tetrahydropyrrolo[1,2-b][1,2,4]oxadiazole-N¹)]palladium(II) complex. The palladium(II) atom exhibits an almost square-planar coordination provided by two trans-arranged chloride anions and a nitrogen atom from each of the two neutral organic ligands. In the crystal, N-H⋯O, O-H⋯O and O-H⋯Cl hydrogen bonds link complex molecules into double layers parallel to the bc plane. [ABSTRACT FROM AUTHOR]

The reaction of the thiosemicarbazones (CH2)4CNN(H)C(S)NHR (R = H, Me) with zinc(II) acetate in methanolic solution proceeds readily under mild conditions to form stable mononuclear complexes Zn[(CH2)4CNNC(S)NHR]2. DNA interaction studies show that the zinc(II) complexes bind to DNA via groove mode and exhibit efficient DNA cleavage activity in the presence of . Also, the complexes display a binding affinity to bovine serum albumin protein with KBSA values of ca 105 M−1. Topoisomerase catalytic inhibition studies suggest that both complexes are efficient topoisomerase-I impeders. Furthermore, the anti-proliferative effects of the two complexes on five human tumor cell lines (Caki-2, MCF-7, CaSki, NCI-H322M and Co-115) indicate that both complexes have the potential to act as effective anticancer drugs. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Six new nickel(II) complexes of thiosemicarbazone Schiff base with isatin moiety [Ni(L1)2–Ni(L6)2] were synthesized through reaction of Ni(II) with (Z)-2-(2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L1H), (Z)-2-(5-methyl-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L2H), (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)-N-phenylhydrazinecarbothioamide (L3H), (Z)-N-methyl-2-(5-nitro-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L4H), (Z)-N-methyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L5H), and (Z)-N-ethyl-2-(5-methyl-2-oxoindolin-3-ylidene)hydrazinecarbothioamide (L6H). The structures of the Ni complexes were characterized through elemental analysis, infrared, and mass spectral data. The structure of the NiL2 complex was further characterized through single-crystal X-ray diffraction. The interaction of these complexes with calf thymus (CT-DNA) exhibited high intrinsic binding constants (Kb = 1.4 × 105–2.4 × 106 M−1), which reflected their intercalative activity toward CT-DNA. This result was also confirmed by viscosity data. Electrophoresis studies revealed that these complexes could cleave the DNA through the oxidative pathway. Thein vitroanti-proliferative study establishes the anticancer potency of these compounds against human colorectal carcinoma cell line. [ABSTRACT FROM PUBLISHER]

In the title complex, [Mn(C22H18N2O4)Cl(CH3OH)], the MnIII centre is in a distorted octahedral geometry, with the N2O2 tetradentate Schiff base ligand in the equatorial plane and the chloride ion and methanol molecule in the axial positions. The dihedral angles between the two outer phenolate rings and the central benzene ring of the tetradentate ligand are 4.08 (14) and 13.61 (14)°. One of the two methoxy substituents on the outer phenolate rings lies almost in the plane of the ring to which it is bound, whereas the other methoxy group is twisted significantly from the corresponding benzene ring plane. In the crystal structure, weak intermolecular C—H⋯Cl interactions link the molecules into infinite chains along the b axis, and these chains are further connected by O—H⋯O hydrogen bonds, weak C—H⋯O and C—H⋯Cl interactions into sheets parallel to the ab plane. The crystal structure is further stabilized by C—H⋯π interactions. [ABSTRACT FROM AUTHOR]

In the molecule of the title compound, [MnCl2(C20H14N4)2]·- H2O, the Mn atom is chelated by two 5,6-diphenyl-3-(2- pyridyl)-1,2,4-triazine molecules in bidentate manner and bonded to two Cl atoms in a distorted octahedral environment. Intra- and intermolecular C—H…Cl and O—H…Cl hydrogen bonds, and also π-π and C—H… π interactions may be effective in the stabilization of the crystal structure. [ABSTRACT FROM AUTHOR]

In the centrosymmetric title compound, [Cd(NO3)2(C20H14N4)2], the dihedral angle between the phenyl rings attached to one heterocycle is 54.13 (5)°. The crystal structure is stabilized by O⋯C, C—H⋯O, C—H⋯π and π–π inter­actions. [ABSTRACT FROM AUTHOR]

In the title complex, [Zn(C20H14N2O4)(H2O)]·3H2O, the ZnII center is in an approximately square-pyramidal coordination environment with the two N and two O atoms of the tetradentate Schiff base ligand forming the basal plane and the coordinated water molecule in the apical position. Three solvent water molecules complete the asymmetric unit. The dihedral angles between the two outer benzene rings of the Schiff base and the central benzene ring are 12.64 (14) and 17.25 (14)°. In the crystal structure, intermolecular O—H...O hydrogen bonds link the molecules into sheets parallel to the ab plane. [ABSTRACT FROM AUTHOR]

The title compound, C28H28N2O4·C5H5N, crystallizes with two molecules in the asymmetric unit. In both molecules, the benzimidazole ring system is essentially planar and forms dihedral angles of 85.35 (5) and 50.51 (5)° with the two benzene rings in one molecule, and 82.93 (5) and 51.30 (5)° in the other molecule. The hydroxy groups are coplanar with the attached benzene rings, whereas the methoxy groups are slightly twisted away from the planes of the attached benzene rings. O—H...O intramolecular hydrogen bonds involving the hydroxy and methoxy groups generate S(6) ring motifs. In the crystal structure, molecules are linked into chains along the [110] direction by O—H...N and C—H...O hydrogen bonds. [ABSTRACT FROM AUTHOR]

The title compound, [Ru(C13H10BrN2O)Cl(C2H6OS)2], shows a distorted octahedral RuII coordination with the N2O tridentate Schiff base ligand and one dimethyl sulfoxide (DMSO) molecule bonded in the equatorial plane, and the Cl and another DMSO ligand occupying the axial positions. In the crystal structure, molecules are linked by N—H...Cl and N—H...O hydrogen bonds into one-dimensional chains along the [100] direction. The crystal structure is further stabilized by weak C—H...O and C—H...Cl interactions. C—H...π interactions are also observed in the crystal structure. [ABSTRACT FROM AUTHOR]

A second monoclinic polymorph of 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine, C20H14N4, is reported. The unit-cell dimensions and the orientation of the pyridine ring with respect to the triazine ring are different from those of the previously reported monoclinic form [Eltayeb, Teoh, Ng, Fun & Ibrahim (2007). Acta Cryst. E 63, o1041–o1042]. In the crystal structure, intermolecular C—H...N interactions connect the molecules into chains along the c axis. The crystal packing is also stabilized by C—H...π and π–π [centroid–centroid distance 3.5917 (9) Å] interactions. The crystal used was twinned and the ratio of the twin components refined to 0.726 (1)/0.274 (1). [ABSTRACT FROM AUTHOR]

In the title compound, [Zn(C22H18N2O2)(H2O)]·CHCl3, the ZnII centre is in a five-coordinate square-pyramidal N2O3 environment, with the N2O2 set of atoms from the Schiff base ligand forming the basal plane; the water molecule occupies the apical position. Intermolecular O—H...O hydrogen bonds and weak C—H...O interactions link the molecules into a chain along [100]. The chains form sheets parallel to the ac plane. [ABSTRACT FROM AUTHOR]

The title compound, [Zn(C36H46N2O2)(C2H6O)]·C2H5OH, adopts a square-pyramidal ZnII coordination, with the N2O2 tetradentate Schiff base ligand bound in the basal plane and the coordinated ethanol molecule occupying the apical site. Inversion-related ZnII complex molecules are linked via O—H...O hydrogen bonding involving the coordinated and uncoordinated ethanol molecules, forming dimers which are stacked along the c axis. Intramolecular C—H...O and C—H...π interactions are observed in the ZnII complex. [ABSTRACT FROM AUTHOR]

The title compound, C22H20N2O4, was synthesized by the reaction of o-phenylenediamine with 5-methoxysalicylaldehyde, as an extension of our investigations of Schiff base ligands and complexes. The central ring makes dihedral angles of 36.35 (5) and 17.81 (5)° with the two phenol rings. Each methoxy group is coplanar with the attached phenol ring. There are two O—H...N intramolecular hydrogen bonds involving the two hydroxy groups, which generate S(6) ring motifs. In the crystal structure, the molecules are arranged into chains along the c axis. These chains form molecular sheets parallel to the ac plane. The crystal is stabilized by intramolecular O—H...N hydrogen bonds and C—H...π interactions. [ABSTRACT FROM AUTHOR]

The title compound, C22H20N2O4, is a Schiff base ligand. The dihedral angles between the central and two outer benzene rings are 2.20 (12) and 58.29 (12)°. Two O—H...N intramolecular hydrogen bonds involving the two hydroxy groups generate S(6) ring motifs. In the crystal structure, molecules are stacked approximately along the a axis and are linked by weak intermolecular C—H...O interactions. The crystal structure is stabilized by intramolecular O—H...N hydrogen bonds, weak C—H...O intermolecular interactions and C—H...π interactions. [ABSTRACT FROM AUTHOR]

In the title compound, [Zn(C20H12Br2N2O2)(C5H5N)], the ZnII atom is in a distorted square-pyramidal environment in both independent molecules. The crystal structure is stabilized by C—H...O and C—H...π interactions, together with short Br...N contacts. [ABSTRACT FROM AUTHOR]

There are two unique molecules of the title mononuclear zinc(II) complex, [Zn(C20H12Cl2N2O2)(C5H5N)], in the asymmetric unit. The ZnII ion is five-coordinate in a distorted square-pyramidal geometry, with the basal plane defined by the two N and two O atoms of the Schiff base ligand and the apical position occupied by the N atom of the pyridine. The N and O atoms of the Schiff base ligand are mutually cis. The molecules are linked by weak C—H...Cl interactions into chains along the b axis. Other molecules are arranged diagonally between adjacent chains and bridge the chains through weak C—H...O interactions. The crystal structure is further stabilized by weak intra- and intermolecular C—H...O hydrogen bonds and C—H...π interactions. [ABSTRACT FROM AUTHOR]

In the title compound, [Zn(C20H14N2O2)(C5H5N)], the ZnII atom is in a distorted square-pyramidal environment. In the crystal structure, intermolecular C—H...O interactions interconnect the molecules into wave-like chains along the c axis. In addition, the crystal packing is further stabilized by weak C—H...π interactions. [ABSTRACT FROM AUTHOR]

In the title compound, [CuCl2(C20H14N4)], the coordination around the Cu atom is approximately square-planar. The dihedral angle between the pyridine and triazine rings is 5.26 (5)°. The crystal structure is stabilized by C—H⋯Cl inter­actions. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, C22H20N2O2, is stabilized by C—H⋯O, C—H⋯π and π–π inter­actions. The central benzene ring forms dihedral angles of 58.55 (6) and 4.02 (6)° with the terminal benzene rings. [ABSTRACT FROM AUTHOR]

The crystal structure of the title compound, C22H20N2O2, is stabilized by intra­molecular O—H⋯N hydrogen bonds and inter­molecular C—H⋯O and C—H⋯π inter­actions. [ABSTRACT FROM AUTHOR]

In the title compound, C20H14N4, the triazine ring adopts a slight twist conformation. In the crystal structure, inter­molecular C—H⋯N inter­actions connect the mol­ecules into chains along the b axis. The crystal packing is also stabilized by π–π and C—H⋯π inter­actions. [ABSTRACT FROM AUTHOR]

The folded mol­ecular conformation of the title compound, C30H24N2O2, is described by the dihedral angles between the benzimidazole ring system and the naphthalene ring systems of 68.2 (1) and 78.4 (1)°. The crystal structure reveals π–π and C—H⋯π inter­actions. [ABSTRACT FROM AUTHOR]

The title compound, C28H40N2O2·0.5CH3OH, crystallizes with two mol­ecules of 1-{2-[(2-hydr­oxy-1-naphth­yl)methyl­eneamino]phenyl­iminiometh­yl}-2-naphtholate and one methanol solvent mol­ecule in the asymmetric unit. All bond lengths and angles are normal. The crystal structure is stabilized by π–π, O—H⋯O and C—H⋯π inter­actions. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, C14H12N2O2, contains four crystallographically independent mol­ecules. The crystal packing is stabilized by π–π, N—H⋯O and C—H⋯π inter­actions. [ABSTRACT FROM AUTHOR]

Copper ion recognition and DNA interaction of a newly synthesized fluorescent Schiff base (HPyETSC) were investigated using UV–vis and fluorescent spectroscopy. Examination using these two techniques revealed that the detection of copper by HPyETSC is highly sensitive and selective, with a detection limit of 0.39 μm and the mode of interaction between HPyETSC and DNA is electrostatic, with a binding constant of 8.97 × 10 4 M −1 . Furthermore, gel electrophoresis studies showed that HPyETSC exhibited nuclease activity through oxidative pathway. [ABSTRACT FROM AUTHOR]

In the title compound, C15H15N3OS, the dihedral angle between the planes of the benzene and pyridine rings is 26.86 (9)°. Intra-molecular N-H⋯O and C-H⋯S hydrogen bonds both generate S(6) rings. The C=O and C=S bonds lie to opposite sides of the mol-ecule. In the crystal, inversion dimers linked by pairs of N-H⋯S hydrogen bonds generate R 2 (2)(8) loops.

In the title compound, C16H17N3OS, the dihedral angle between the planes of the benzene and pyridine rings is 71.33 (15)°. An intra-molecular N-H⋯O hydrogen bond is present. In the crystal, weak aromatic C-H⋯O hydrogen bonds link the mol-ecules into chains extending along a.

In the title compound, C(11)H(11)FN(4)OS, an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, mol-ecules form chains through N-H⋯O hydrogen bonds, which are extended by N-H⋯S hydrogen bonds into an infinite three-dimensional network.

In the crystal structure of the title compound, C(7)H(14)N(4)OS, mol-ecules are linked through N-H⋯S and O-H⋯N hydrogen bonds and C-H⋯S interactions, forming chains propagating along [21-1].

The asymmetric unit of the title compound, [Ni(C(15)H(11)N(4)OS)(2)]·C(3)H(7)NO, contains one Ni(II) complex mol-ecule and one disordered dimethyl-formamide solvent mol-ecule. The Ni(II) ion is six-coordinated in a distorted octa-hedral geometry by two N, two O and two S atoms. An intra-molecular C-H⋯S hydrogen bond generates an S(6) ring motif. In the crystal, mol-ecules are linked through inter-molecular N-H⋯S, N-H⋯O, C-H⋯N, C-H⋯O and C-H⋯S hydrogen bonds into infinite two-dimensional network parallel to the ab plane. The structure is further stablized by weak C-H⋯π inter-actions. The dimethylformamide solvent molecule is disordered over two sets of sites in a 0.514 (15):0.486 (15) ratio.

In the title compound, C(10)H(9)N(5)O(3)S, an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, mol-ecules are linked via N-H⋯S hydrogen bonds into a zigzag chain along the b axis. C-H⋯O inter-actions are observed between the chains.

In the title compound, C(11)H(12)N(4)OS, an intra-molecular N-H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, the mol-ecules form a helical chain along the a axis through an N-H⋯O hydrogen bond. These chains are extended by an N-H⋯S hydrogen bond and a C-H⋯π inter-action into a three-dimensional network.

In the title compound, C(10)H(9)ClN(4)OS, an intra-molecular N-H⋯O hydrogen-bonding inter-action and an N-H⋯N inter-action generate ring motifs [graph sets S(6) and S(5), respectively]. In the crystal, mol-ecules form a chain through N-H⋯O hydrogen bonds, and these are extended by N-H⋯S hydrogen-bonding inter-actions into an infinite three-dimensional network. The crystal structure also exhibits weak C-H⋯π inter-actions.

In the title compound, C(15)H(12)N(4)OS, the dihedral angle between the nine-membered indolin-2-one ring system and the phenyl ring is 2.72 (7)°. Intra-molecular cyclic N-H⋯O and C-H⋯S hydrogen-bonding inter-actions [graph set S(6)] are present, as are weak N-H⋯N inter-actions [graph set S(5)]. In the crystal, mol-ecules form centrosymmetric cyclic dimers through pairs of N-H⋯O hydrogen bonds [graph set R(2) (2)(8)] and these are extended by C-H⋯S inter-actions. The crystal structure also features weak C-H⋯π inter-actions.

In the title complex, [Ni(C(7)H(14)N(4)OS)(2)]Cl(2), the Ni(II) ion is six-coordinated in a distorted octa-hedral geometry by four N atoms from the two imine and two oxime groups, and two S atoms from the thione groups. Two chloride ions complete the asymmetric unit. In the crystal, mol-ecules are linked through N-H⋯Cl and O-H⋯Cl hydrogen bonds into an infinite chain propagating along [101].

The title compound, C(15)H(11)FN(4)OS, crystallizes with three independent mol-ecules (A, B and C) in the asymmetric unit. The dihedral angles between the nine-membered 5-fluoro-indolin-2-one ring system and the benzene ring are 22.14 (11), 12.56 (11) and 3.70 (11)° in mol-ecules A, B and C, respectively. In all three mol-ecules, intra-molecular cyclic N-H⋯O and C-H⋯S hydrogen-bonding inter-actions [graph set S(6)] are present in the N-N-C-N chain between the ring systems. In the crystal, the A mol-ecules form centrosymmetric cyclic dimers through inter-molecular N-H⋯O hydrogen bonds, which are linked into a supramolecular chain along [100] via C-H⋯F interactions; each type of hydrogen bond has graph set graph set R(2) (2)(8). A similar chain stabilised by similar interactions and also along [100] but, comprising alternating molecules of B and C is found. The latter chains are connected via C-H⋯S interactions, forming a layer with a zigzag topology parallel to (001).

The asymmetric unit of the title compound, [Ni(C(6)H(12)N(4)OS)(2)]Cl(2), contains two independent Ni(II) complex cations and four chloride anions. Each Ni(II) ion is six-coordinated in a distorted octa-hedral geometry by four N atoms from the two imine and two oxime groups and two S atoms from the thione group. In the crystal, the cations and anions are linked through N-H⋯Cl and O-H⋯Cl hydrogen bonds into infinite chains propagating along [10[Formula: see text]]. Weak inter-molecular C-H⋯O and C-H⋯Cl hydrogen bonds are also observed.