Synthesis, Characterization and Fluorescence Properties of Zn(II) and Cu(II) Complexes: DNA Binding Study of Zn(II) Complex.

Zinc(II) and copper(II) complexes containing Schiff base, 2- methoxy-6((E)-(phenylimino) methyl) phenol ligand (HL) were synthesized and characterized by elemental analysis, IR, NMR, and single crystal X-ray diffraction technique. The fluorescence properties and quantum yield of zinc complex were studied. Our data showed that Zn complex could bind to DNA grooves with Kb = 10(4) M(-1). Moreover, Zn complex could successfully be used in staining of DNA following agarose gel electrophoresis. MTT assay showed that Zn complex was not cytotoxic in MCF-7 cell line. Here, we introduce a newly synthesized fluorescence probe that can be used for single and double stranded DNA detection in both solution and agarose gels.

Spectroscopic and molecular modeling based approaches to study on the binding behavior of DNA with a copper (II) complex.

Blocking the division of tumor cells by small-molecules is currently of great interest for the design of new antitumor drugs. The interaction of a new metal complex with DNA was investigated through several techniques. Absorption spectroscopy and gel electrophoresis studies on the interaction of the Cu-complex of (2a-4mpyH)2 [Cu(pyzdc)2 (H2O)2].6 H2O with DNA have shown that this complex can bind to CT-DNA with binding constant 3.99 × 10(5) M(-1). The cyclic voltammetry (CV) responses of the metal complex in the presence of CT-DNA have shown that the metal complex can bind to CT-DNA through partial intercalation mode and this is consistent with molecular docking analysis, quenching process and thermal denaturation experiments. The cytotoxicity of this complex has been evaluated by MTT assay. The results of cell viability assay on DU145 cell line revealed that the metal complex had cytotoxic effects.

Structure-activity relationship for Fe(III)-salen-like complexes as potent anticancer agents.

Quantitative structure activity relationship (QSAR) for the anticancer activity of Fe(III)-salen and salen-like complexes was studied. The methods of density function theory (B3LYP/LANL2DZ) were used to optimize the structures. A pool of descriptors was calculated: 1497 theoretical descriptors and quantum-chemical parameters, shielding NMR, and electronic descriptors. The study of structure and activity relationship was performed with multiple linear regression (MLR) and artificial neural network (ANN). In nonlinear method, the adaptive neuro-fuzzy inference system (ANFIS) was applied in order to choose the most effective descriptors. The ANN-ANFIS model with high statistical significance (R (2) train = 0.99, RMSE = 0.138, and Q (2) LOO = 0.82) has better capability to predict the anticancer activity of the new compounds series of this family. Based on this study, anticancer activity of this compound is mainly dependent on the geometrical parameters, position, and the nature of the substituent of salen ligand.

catena-Poly[[di-µ2-aqua-hexaaquabis(µ3-4-oxidopyridine-2,6-dicarboxylato)trimanganese(II)] trihydrate]: a new one-dimensional coordination polymer based on a trinuclear Mn(II) complex of chelidamic acid.

4-Hydroxypyridine-2,6-dicarboxylic acid (chelidamic acid, hypydc[H]H2) reacts with MnCl2·2H2O in the presence of piperazine in water to afford the title complex, {[Mn3(C7H2NO5)2(H2O)8]·3H2O}n or {[Mn3(hypydc)2(H2O)8]·3H2O}n. This compound is a one-dimensional coordination polymer, with the twofold symmetric repeat unit containing three metal centres. Two different coordination geometries are observed for the two independent Mn(II) metal centres, viz. a distorted pentagonal bipyramid and a distorted octahedron. The 4-oxidopyridine-2,6-dicarboxylate anions and two of the water molecules act as bridging ligands. The zigzag-like geometry of the coordination polymer is stabilized by hydrogen bonds. O-H···O and C-H···O hydrogen bonds and water clusters consolidate the three-dimensional network structure.

New rac-XP(O)(OC6H5)(NHC6H4-p-CH3) [X = N(CH3)(cyclo-C6H11) and NH(C3H5)] and rac-(C6H5CH2NH)P(O)(OC6H5)(NH-cyclo-C6H11) mixed-amide phosphinates.

The mixed-amide phosphinates, rac-phenyl (N-methylcyclohexylamido)(p-tolylamido)phosphinate, C20H27N2O2P, (I), and rac-phenyl (allylamido)(p-tolylamido)phosphinate, C16H19N2O2P, (II), were synthesized from the racemic phosphorus-chlorine compound (R,S)-(Cl)P(O)(OC6H5)(NHC6H4-p-CH3). Furthermore, the phosphorus-chlorine compound ClP(O)(OC6H5)(NH-cyclo-C6H11) was synthesized for the first time and used for the synthesis of rac-phenyl (benzylamido)(cyclohexylamido)phosphinate, C19H25N2O2P, (III). The strategies for the synthesis of racemic mixed-amide phosphinates are discussed. The P atom in each compound is in a distorted tetrahedral (N(1))P(=O)(O)(N(2)) environment. In (I) and (II), the p-tolylamido substituent makes a longer P-N bond than those involving the N-methylcyclohexylamido and allylamido substituents. In (III), the differences between the P-N bond lengths involving the cyclohexylamido and benzylamido substituents are not significant. In all three structures, the phosphoryl O atom takes part with the N-H unit in hydrogen-bonding interactions, viz. an N-H···O=P hydrogen bond for (I) and (N-H)(N-H)···O=P hydrogen bonds for (II) and (III), building linear arrangements along [001] for (I) and along [010] for (III), and a ladder arrangement along [100] for (II).

2-Amino-pyridinium bis-(pyridine-2,6-dicarboxyl-ato)ferrate(III).

In the title compound, (C(5)H(7)N(2))[Fe(C(7)H(3)NO(4))(2)] or [2-apyH][Fe(pydc)(2)], the asymmetric unit contains an [Fe(pydc)(2)](-) (pydc is pyridine-2,6-dicarboxyl-ate) anion and a protonated 2-amino-pyridine cation ([2-apyH](+)). The complex anion contains an Fe(III) atom within a distorted octahedral FeN(2)O(4) coordination geometry. N-H⋯O and C-H⋯O hydrogen bonding, offset π-π stacking [centroid-centroid distance = 3.805 (13) Å] and C=O⋯π inter-actions [3.494 (14) Å] generate a three-dimensional network structure.

Poly[(µ(2)-2-amino-pyrimidine-κ(2)N(1):N(3))di-µ(2)-chlorido-mercury(II)].

The title compound, [HgCl(2)(C(4)H(5)N(3))](n), features a two-dimensional network parallel to (001) that is based on an Hg(II) atom octahedrally coordinated by four µ(2)-Cl atoms and two µ(2)-2-amino-pyrimidine (apym) ligands in trans positions, yielding a distorted HgCl(4)N(2) octa-hedron. The coordination network can be described as an uninodal 4-connected net with the sql topology. The Hg(II) ion lies on a site of -1 symmetry and the apym ligand lies on sites of m symmetry with the mirror plane perpendicular to the pyrimidine plane and passing through the NH(2) group N atom. This polymeric structure is stabilized by N-H⋯Cl hydrogen bonds and columnar π-π stacking of pyrimidine rings, with a centroid-centroid distance of 3.832 (2) Å.

9-Amino-acridinium bis-(pyridine-2,6-dicarboxyl-ato-κ(3)O(2),N,O(6))ferrate(III) tetra-hydrate.

The asymmetric unit of the title compound, (C(13)H(11)N(2))[Fe(C(7)H(3)NO(4))(2)]·4H(2)O, contains a 9-amino-acridinium cation, one anionic complex and four uncoordinated water mol-ecules. In the anionic complex, the Fe(III) ion is six-coordinated by two almost perpendicular [dihedral angle = 88.78 (7)°] pyridine-2,6-dicarboxyl-ate ligands in a distorted octa-hedral geometry. In the crystal, anions are connected into chains along [10-1] by weak C-H⋯O inter-actions, which create ten-membered hydrogen-bonded R(2) (2)(10) rings. These chains are linked by three-membered water clusters. The final three-dimensional network is constructed by numerous inter-molecular O-H⋯O and N-H⋯O inter-actions.

Dianilinium bis-(pyridine-2,6-dicarboxyl-ato-κ(3)O(2),N,O(6))cuprate(II) hexa-hydrate.

The asymmetric unit of the title complex, (C(6)H(8)N)(2)[Cu(C(7)H(3)NO(4))(2)]·6H(2)O, contains half a copper(II)-dipicolinate complex located on a twofold rotation axis, one protonated aniline mol-ecule and three solvent water mol-ecules. The Cu(II) atom is coordinated by four O atoms and two N atoms from two dipicolinate ligands in a distorted octa-hedral environment. In the crystal, the components are linked into a three-dimensional framework by inter-molecular O-H⋯O and N-H⋯O inter-actions.

Tris{4-[(2H-tetra-zol-5-yl)meth-yl]morpholinium} dodeca-tungstophosphate hexa-hydrate.

The title heteropolyoxidotungstate-based inorganic-organic hybrid material, (C(6)H(12)N(5)O)(3)[W(12)(PO(4))O(36)]·6H(2)O, consists of one α-Keggin-type [W(12)(PO(4))O(36)](3-) polyoxidometalate anion (POM), three crystallographically independent 4-[(2H-tetra-zol-5-yl)meth-yl]morpholinium cations and six water mol-ecules of crystallization. The morpholine ring of the cation adopts a chair conformation. The anion shows characteristic features with respect to bond lengths and angles. An extensive network of N-H⋯O, N-H⋯N, O-H⋯O and O-H⋯N hydrogen-bonding inter-actions between the organic cations, inorganic anion and the crystal water mol-ecules lead to a three-dimensional structure. Moreover, six uncoordinated water mol-ecules increase the number of hydrogen bonds in the network and lead to the formation of (H(2)O)(∞) clusters.

Bis(2-amino-6-methyl-pyridinium) trans-diaqua-bis-(pyrazine-2,3-dicarboxyl-ato)cobaltate(II) octa-hydrate.

The title compound, (C(6)H(9)N(2))(2)[Co(C(6)H(2)N(2)O(4))(2)(H(2)O)(2)]·8H(2)O, was obtained by the reaction of CoCl(2)·6H(2)O with 1,4-pyrazine-2,3-dicarb-oxy-lic acid and 2-amino-6-methyl-pyridine in aqueous solution (molar ratio 1:2:2). The Co(II) ion is situated on an inversion centre and is coordinated by two O and two N atoms of two symmetry-related 1,4-pyrazine-2,3-dicarboxyl-ate ligands and two water mol-ecules and has a disorted octa-hedral coordination environment. The asymmetric unit also contains four water mol-ecules. In the crystal, extensive inter-molecular classical N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds and π-π stacking inter-actions [centroid-centroid distance = 3.490 (1) Å] connect the various components, forming a three-dimensional network.

Tetra-kis{4-[(2H-tetra-zol-5-yl)meth-yl]morpholin-4-ium} dodeca-tungstosilicate hexa-hydrate.

The crystal structure of the title compound, (C(6)H(12)N(5)O)(4)[W(12)(SiO(4))O(36)]·6H(2)O, consists of an α-Keggin-type [W(12)(SiO(4))O(36)](4-) polyoxidoanion, four [(2H-tetra-zol-5-yl)meth-yl]morpholinium cations and six uncoordinated water mol-ecules. In the cations, the morpholine rings display chair conformations. Extensive N-H⋯O, N-H⋯N, O-H⋯O and O-H⋯N hydrogen bonds are present in the crystal structure.

Phenyl bis-(m-tolyl-amido)-phosphinate.

The P atom of the title compound, C(20)H(21)N(2)O(2)P, has a distorted tetra-hedral configuration; the bond angles at P are in the range 96.11 (6)-117.32 (8)°. The N atom exhibits sp(2) character. In the crystal, mol-ecules are connected via N-H⋯O hydrogen bonds into bands along the a axis, consisting of R(2) (2)(8) rings.

Phenyl bis-(morpholin-4-yl-amido)-phosphinate.

In the title compound, C(14)H(23)N(4)O(4)P, the P atom is in a distorted tetra-hedral environment with bond angles in the range 96.87 (6)-119.86 (6)°. The two morpholinyl groups adopt a chair conformation. The phenyl ring is disordered over two sets of sites with equal occupancies [0.500 (2)]. In the crystal, adjacent mol-ecules are linked via N-H⋯O hydrogen bonds into an extended chain running parallel to the a axis. Only one of the amidate N-H groups is involved in hydrogen bonding.

Bis(2-amino-6-methyl-pyridinium) trans-diaqua-bis-(pyrazine-2,3-dicarboxyl-ato)cuprate(II) hexa-hydrate.

The title compound, (C(6)H(9)N(2))(2)[Cu(C(6)H(2)N(2)O(4))(2)(H(2)O)(2)]·6H(2)O, was obtained by the reaction of CuCl(2)·2H(2)O with pyrazine-2,3-dicarb-oxy-lic acid (pyzdcH(2)) and 2-amino-6-methyl-pyridine (2a-6mpy) in aqueous solution. The Cu(II) atom is located on an inversion centre and has an overall octa-hedral coordination environment. Two N and two O atoms from (pyzdc)(2-) ligands define the equatorial plane and two water mol-ecules are in axial positions, resulting in a typical tetra-gonally Jahn-Teller-distorted environment. Extensive classical O-H⋯O, O-H⋯N and N-H⋯O and non-classical C-H⋯O hydrogen bonds, as well as π-π stacking inter-actions between aromatic rings of the cations [centroid-centroid distance = 3.58 (9) Å], lead to the formation of a three-dimensional supra-molecular structure.

9-Amino-acridinium nitrate monohydrate.

The pyridine N atom of the cation in the title hydrated salt, C(13)H(11)N(2) (+)·NO(3) (-)·H(2)O, is protonated; the N atom of the NH(2) group shows a planar conformation. The former N atom is hydrogen bonded to a water mol-ecule. The amino group is involved in three N-H⋯O hydrogen bonds with two neighboring nitrate anions. The water mol-ecule is hydrogen bonded to two adjacent nitrate anions. In the crystal, this results in a layered network.

Supramolecular network of a framework material supported by the anion-π linkage of Keggin-type heteropolyoxotungstates: experimental and theoretical insights.

A novel inorganic-organic hybrid, {Na[Tb(L)(H2O)4]3(SiW12O40)}·4H2O, in which L = 4-hydroxypyridine-2,6-dicarboxylic acid (chelidamic acid), was prepared and characterized by elemental analyses, Fourier transform infrared spectroscopy, and single-crystal X-ray diffraction. It consists of a trinuclear terbium cluster bonded to a Keggin-type polyoxotungstate. In the terbium cluster three crystallographically equivalent Tb3+ ions are bridged by carboxylate oxygen atoms belonging to three chelidamic acid units to form an equilateral triangle. These triangle units connect to each other through hydrogen-bonding and anion-π interactions. A CSD survey was carried out focusing on the cation and the ligand roles in the structure formation of this type of compounds. Finally, DFT calculations were used to analyse the role of the anion-π interactions that are important in the formation of 1D supramolecular assemblies in the solid state. The noncovalent interaction plot (NCIplot) computational tool has been used to characterize the anion-π interaction.

Monoclinic modification of N-benzyl-propan-2-aminium chloride.

In the title salt, C(10)H(16)N(+)·Cl(-), the cations and anions are linked by two N-H⋯Cl hydrogen bonds, forming a centrosymmetric tetramer.

catena-Poly[diacridinium [zinc(II)-di-µ-pyrazine-2,3-dicarboxyl-ato-κN,O:O;O:N,O]].

The crystal structure of the title compound, {(C(13)H(10)N)(2)[Zn(C(6)H(2)N(2)O(4))(2)]}(n), consists of polymeric Zn complex anions and discrete acridinium cations. The Zn cation, located on an inversion center, is N,O-chelated by two pyrazine-2,3-dicarboxyl-ate (pyzdc) anions in the basal plane, and is further coordinated by two carboxyl-ate O atoms from adjacent pyzdc anions in the axial directions with a longer Zn-O bond distance, forming a distorted ZnN(2)O(4) coordination geometry. The pyzdc anions bridge the Zn cations, forming polymeric chains running along the crystallographic b axis. The acridinium cations are linked to the complex chains via N-H⋯O and C-H⋯O hydrogen bonding. Significant π-π stacking between parallel acridinium ring systems is observed in the crystal structure, face-to-face distances being 3.311 (3) and 3.267 (4) Å.

2-Amino-pyrimidinium 4-hy-droxy-pyridinium-2,6-dicarboxyl-ate monohydrate.

In the crystal structure of the title compound, C(4)H(6)N(3) (+)·C(7)H(4)NO(5) (-)·H(2)O, inter-molecular N-H⋯N, N-H⋯O and O-H⋯O hydrogen bonds link the cations and anions into almost planar sheets parallel to (102). These hydrogen-bonded sheets are packed into the crystal with the formation of centrosymmetric voids of 68 Å(3), which are filled by the water mol-ecules, each of which is disordered over four positions.