RESUMO
The structure of the title compound, cis-[PtCl(2)(C(2)H(5)N(5))(2)], was analysed using in-house X-ray powder diffraction data at room temperature. The structure was solved by direct methods and refined using Rietveld analysis. A slightly distorted square-planar coordination geometry is formed around the Pt atom by two Cl atoms and two ring N atoms of the 2-methyl-2H-tetrazol-5-amine ligands, which are in a cis configuration. The planes of the tetrazole rings are inclined at 79.7 (7) and 73.8 (6)° with respect to the coordination plane, with their substituents oriented in such a way that the complex as a whole has approximate C(2) symmetry. Intermolecular N-H···Cl hydrogen bonds mediate the formation of a three-dimensional supramolecular network.
Assuntos
Cisplatino/química , Compostos Organoplatínicos/química , Tetrazóis/química , Cristalografia por Raios X , Ligação de Hidrogênio , Estrutura Molecular , Difração de Pó , Difração de Raios XRESUMO
A nonclassical tetrazole isostere of glycine, viz. zwitterionic 5-ammoniomethyl-1H-tetrazolide, C(2)H(5)N(5), (I), crystallizes in the chiral P3(1) space group, similar to gamma-glycine. The crystal packing of (I) is determined by a set of classical hydrogen bonds, forming a three-dimensional network that is practically the same as that in gamma-glycine. The Cu(II) complex of (I), poly[[bis(mu(2)-5-aminomethyl-1H-tetrazolido-kappa(3)N(1),N(5):N(4))copper(II)] dihydrate], {[Cu(C(2)H(4)N(5))(2)].2H(2)O}(n), (II), is a layered coordination polymer formed as a result of tetrazole ring bridges. The Cu(II) cations lie on inversion centres, are surrounded by four anions and adopt elongated octahedral coordination. Water molecules are located in the interlayer space and connect the layers into a three-dimensional network via a system of hydrogen bonds.
Assuntos
Cobre/química , Cristalografia por Raios X , Glicina/análogos & derivados , Tetrazóis/química , Modelos Moleculares , Estrutura MolecularRESUMO
The complex catena-poly[[dibromidocopper(II)]-bis(mu-2-methyl-2H-tetrazol-5-amine)-kappa(2)N(4):N(5);kappa(2)N(5):N(4)], [CuBr(2)(C(2)H(5)N(5))(2)](n), (I), and the isotypic chloride complex catena-poly[[dichloridocopper(II)]-bis(mu-2-methyl-2H-tetrazol-5-amine)-kappa(2)N(4):N(5);kappa(2)N(5):N(4)], [CuCl(2)(C(2)H(5)N(5))(2)](n), (II), were investigated by X-ray powder diffraction at room temperature. The crystal structure of (I) was solved by direct methods, while the Rietveld refinement of (II) started from the atomic coordinates of (I). In both structures, the Cu atoms lie on inversion centres, adopting a distorted octahedral coordination of two halogen atoms, two tetrazole N atoms and two 5-amine group N atoms. Rather long Cu-N(amine) bonds allow consideration of the amine group as semi-coordinated. The compounds are one-dimensional coordination polymers, formed as a result of 2-methyl-2H-tetrazol-5-amine ligands bridging via a tetrazole N atom and the amine N atom. In the polymeric chains, adjacent Cu atoms are connected by two such bridges.
RESUMO
The title cobalt(II) complex, [CoCl(2)(C(3)H(6)N(4)O)(4)], was obtained from metallic cobalt by direct synthesis. There are two Co atoms in the asymmetric unit, each lying on an inversion centre and adopting a distorted octa-hedral coordination. Classical and non-classical hydrogen bonds are responsible for formation of a three-dimensional polymeric network in the crystal.
RESUMO
The asymmetric unit of the title compound, [CoCl(2)(C(3)H(6)N(4))](n), contains two Co atoms, both lying on inversion centres, two Cl atoms and one 1,5-dimethyl-tetra-zole ligand. The coordination polyhedra of both Co atoms adopt flattened octa-hedral geometry, with two N atoms from two ligands in axial positions and four Cl atoms in equatorial sites. Neighbouring Co atoms are linked together via two bridging Cl atoms and one tetra-zole ring to form polymeric chains running along the a axis.
RESUMO
The geometric features of 1-(4-nitrophenyl)-1H-tetrazol-5-amine, C(7)H(6)N(6)O(2), correspond to the presence of the essential interaction of the 5-amino group lone pair with the pi system of the tetrazole ring. Intermolecular N-H...N and N-H...O hydrogen bonds result in the formation of infinite chains running along the [110] direction and involve centrosymmetric ring structures with motifs R(2)(2)(8) and R(2)(2)(20). Molecules of {(E)-[1-(4-ethoxyphenyl)-1H-tetrazol-5-yl]iminomethyl}dimethylamine, C(12)H(16)N(6)O, are essentially flattened, which facilitates the formation of a conjugated system spanning the whole molecule. Conjugation in the azomethine N=C-N fragment results in practically the same length for the formal double and single bonds.
Assuntos
Aminas/química , Metilaminas/química , Tetrazóis/química , Cristalografia por Raios X , Ligação de Hidrogênio , Metilação , Modelos Moleculares , Estrutura Molecular , EstereoisomerismoRESUMO
The crystal structure of the title polymeric complex, [CuCl(2)(C(3)H(6)N(4)O)(2)](n), was obtained by the Rietveld refinement from laboratory X-ray powder diffraction data collected at room temperature. The unique Cu(II) ion lies on an inversion center and is in a slightly distorted octa-hedral coordination environment. In the hydroxy-ethyl group, all H atoms, the O atom and its attached C atom are disordered over two positions; the site occupancy factors are ca 0.6 and 0.4. The OH group is involved in an intra-molecular O-Hâ¯N hydrogen bond.
RESUMO
For the first time, a representative of the 2,5-disubstituted tetrazoles, namely, 2-tert-butyl-5-(2-pyridyl)-2H-tetrazole (L), has been found to participate in oxidative dissolution of copper powder in homometalic systems Cu0LNH4XDMSO (X = Cl, SCN, ClO4) and heterobimetallic ones Cu0Mn(OAc)2LNH4OAcSolv (Solv = DMSO, DMF), providing the formation of molecular homometallic complexes [CuL2Cl2] (1), [CuL2(SCN)2] (2), and [CuL2(H2O)](ClO4)2 (3), heterobimetallic complex [Cu2MnL2(OAc)6] (4) from DMF solution and its mixture with complex [Cu2MnL2(OAc)6]·2DMSO (5) from DMSO solution. Free ligand L and complexes 14 were characterized by elemental analysis, IR spectroscopy, thermal and X-ray single crystal analyses, whereas complex 5 was characterized by X-ray analysis only. Compounds 13 are mononuclear complexes, with chelating coordination mode of L via the tetrazole ring N4 and pyridine ring N7 atoms. Heterobimetallic complexes 4 and 5 possess trinuclear structures, with a linear CuMnCu arrangement of the metal atoms, linked by the acetate anions; each copper(II) atom is decorated by a chelating unit of L via the tetrazole ring N1 and pyridine ring N7 atoms in complex 4, and via the N4, N7 atoms in complex 5. Temperature-dependent magnetic susceptibility measurements of complex 4 revealed a weak antiferromagnetic coupling between the paramagnetic copper(II) and manganese(II) ions (J = −2.5 cm(−1), g(Cu) = 2.25 and g(Mn) = 2.01), with magnetic exchange through the acetato bridges.
Assuntos
Quelantes/química , Complexos de Coordenação/síntese química , Cobre/química , Manganês/química , Piridinas/química , Tetrazóis/química , Complexos de Coordenação/química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Estrutura MolecularRESUMO
Two series of tetrazole-containing platinum(II) and palladium(II) chlorido complexes, trans-[ML(2)Cl(2)] (M=Pt, Pd) and cis-[PtL(2)Cl(2)]·nH(2)O (n=0, 1), where L is 1- or 2-substituted 5-aminotetrazole, have been synthesized and thoroughly characterized. Configuration of platinum(II) complexes obtained from the reaction of 5-aminotetrazoles with K(2)PtCl(4) has been found to vary depending on the nature of tetrazole derivatives and reaction conditions. According to in vitro cytotoxic evaluation, only platinum complexes display noticeable antiproliferative effect, and their cytotoxicity depends strongly on their geometry and hydrophobicity of the carrier ligands. The most promising complexes are cis-[Pt(1-apt)(2)Cl(2)]·H(2)O and cis-[Pt(2-abt)(2)Cl(2)]·H(2)O, where 1-apt is 5-amino-1-phenyltetrazole and 2-abt is 5-amino-2-tert-butyltetrazole. In comparison with cisplatin, they show comparable cytotoxic potency against cisplatin-sensitive human cancer cell lines, cis-[Pt(2-abt)(2)Cl(2)]·H(2)O performing substantially higher activity against cisplatin-resistant cell lines. Cell cycle studies in H1299 cell line indicated that cis-[Pt(2-abt)(2)Cl(2)]·H(2)O induced apoptosis launched from G2 accumulations. The DNA interaction with cis-[Pt(1-apt)(2)Cl(2)]·H(2)O was followed by UV spectroscopy, circular dichroism, hydrodynamic and electrophoretic mobility studies. Both cis-[Pt(1-apt)(2)Cl(2)]·H(2)O and cis-[Pt(2-abt)(2)Cl(2)]·H(2)O complexes appeared to be significantly less toxic than cisplatin in mice, while only compound cis-[Pt(1-apt)(2)Cl(2)]·H(2)O displayed noticeable efficacy in vivo.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Cisplatino/análogos & derivados , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacologia , Paládio/química , Animais , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Benzotiazóis/química , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral/efeitos dos fármacos , Dicroísmo Circular , Cisplatino/farmacologia , DNA/química , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Feminino , Humanos , Isomerismo , Masculino , Estrutura Molecular , Compostos Organoplatínicos/síntese química , Espectrofotometria Ultravioleta , Tetrazóis/químicaRESUMO
A novel ligand, 5-mercaptomethyltetrazole, is applied to the direct colloidal synthesis of highly luminescent (quantum yield of up to 60%) water-soluble CdTe nanocrystals. In the synthesis the 5-mercaptomethyltetrazole behaves analogously to the widely used thioglycolic acid, providing the additional advantage of solubility of the resulting nanocrystals in methanol. Moreover, the 5-mercaptomethyltetrazole-capped nanocrystals possess the unique ability to reversibly form fine 3D networks (hydrogels) upon the addition of metal salts.
RESUMO
While bis(1-methyl-1H-tetrazol-5-yl)diazene, C4H6N10, (I), has no crystallographically imposed symmetry, in the two title chlorocopper(I) complexes, [Cu2Cl2(C4H6N10)]n, (II), and [CuCl(C4H6N10)]n, (III), the organic ligands lie across centres of inversion; in (III), the Cu and Cl atoms additionally lie about a twofold rotation axis in the space group P2/c. Complex (II) forms a two-dimensional coordination polymer containing tetrahedrally coordinated Cu(I) atoms, and complex (III) forms a one-dimensional coordination polymer containing five-coordinate square-pyramidal Cu(I) atoms.
RESUMO
The crystal structure of the polymeric title complex, [CuCl2(C3H6N4)]n, has been solved from laboratory X-ray powder diffraction data collected at room temperature. The structural model obtained was refined with the Rietveld method using geometric soft restraints. There are two Cu atoms, two Cl atoms and one 1,5-dimethyltetrazole ligand in the asymmetric unit. Both Cu atoms lie on inversion centres and adopt essentially elongated octahedral coordination. Within the octahedra, the elongated axial positions are occupied by Cl atoms, while two Cl and two N atoms (N3 and N4 of the tetrazole ring) are in equatorial sites. Each Cl atom forms an asymmetric bridge between neighbouring Cu atoms, which are also bridged via the N3-N4 bond of the tetrazole ring. These bridges result in the formation of polymeric chains, running along the a axis, with weak C-H...Cl hydrogen bonds crosslinking the chains.
RESUMO
Two polymeric complexes, [CuCl2L2]n, where L is 2-propyltetrazole (C4H8N4) or 2-allyltetrazole (C4H6N4), are the first coordination polymers of 2-substituted tetrazoles in which only the tetrazole rings bridge neighbouring Cu atoms. In both complexes, the Cu atoms lie on inversion centres and are six-coordinated in tetragonally distorted octahedral geometries, CuCl2N4, with two N1 tetrazole ring atoms in the axial positions and two Cl atoms and two N4 tetrazole ring atoms in the equatorial sites. The Cl atoms do not participate in the polymeric layer formation.
RESUMO
The title polymeric compound, [CuCl(2)(C(5)H(10)N(4))(2)](n), is the first structurally characterized complex with a bulky 1-alkyltetrazole ligand. The coordination polyhedron of the Cu atom is an elongated octahedron. The equatorial positions of the octahedron are occupied by the two Cl atoms, with Cu-Cl distances of 2.2920 (8) and 2.2796 (9) A, and by the two N-4 atoms of the tetrazole ligands, with Cu-N distances of 2.023 (2) and 2.039 (2) A. Two symmetry-related Cl atoms occupy the axial positions, at distances of 2.8244 (8) and 3.0174 (8) A from the Cu atom. The [CuCl(2)(C(5)H(10)N(4))(2)] units form infinite chains extended along the b axis, linked together only by van der Waals interactions. The skeleton of each chain consists of Cu and Cl atoms.
RESUMO
In the molecule of the title 1,5-disubstituted tetrazole, C(13)H(17)N(5), the tetrazole and benzene rings are not coplanar, having a dihedral angle of 42.96 (5) degrees between them. The piperidine fragment adopts a chair conformation, and there is a non-classical intramolecular contact between the benzene H atom and the piperidine N atom. Intermolecular C-H...pi interactions involving the piperidine C-H groups and the benzene rings are responsible for the formation of two-dimensional networks, extending parallel to the ab plane. These networks are linked together into a three-dimensional polymeric structure via pi-pi stacking interactions between the tetrazole rings of two adjacent molecules.
RESUMO
The title compound, C(8)H(13)N(5), is a novel functionally substituted 5-alkyltetrazole. The substituent on the tetrazole C atom is symmetrical, with intrinsic symmetry close to m. There is intermolecular N-H.N hydrogen bonding between adjacent tetrazole rings, which is responsible for the formation of one-dimensional polymeric chains running along the c axis. The polycrystalline compound exhibits frequency doubling for incident light (lambda = 1064 nm) from a YAG:Nd pulsed laser.
RESUMO
In the polymeric title complex, [CuCl(2)(C(3)H(6)N(4))(2)](n), there are two ligands in the asymmetric unit. The Cu atom adopts an elongated octahedral geometry, with two 2-ethyltetrazole ligands [Cu-N = 2.0037 (16) and 2.0136 (16) A] and two Cl atoms [Cu-Cl = 2.2595 (6) and 2.2796 (6) A] in equatorial positions. A Cl atom and a symmetry-related 2-ethyltetrazole molecule [Cu-Cl = 2.8845 (8) A and Cu-N = 2.851 (2) A] lie in the axial positions of the octahedron. One of the two 2-ethyltetrazole ligands of the asymmetric unit exhibits bidentate binding to two Cu atoms through two N atoms of the tetrazole ring, whereas the other ligand is coordinated in a monodentate fashion via one tetrazole N atom. The Cu-atom octahedra form dimer entities by sharing edges with equatorial and axial Cl atoms. The dimers are linked together through the 2-ethyltetrazole ligands to form one-dimensional polymeric zigzag chains extending along the b axis. The chains are connected into infinite layers parallel to the (10-1) plane via the 2-ethyltetrazole ligands.
RESUMO
The title compound, C(7)H(13)N(5), a tetrazole analogue of betaines, exists as a zwitterion, with the H atom of the tetrazole ring being transferred to the piperidine ring N atom. The tetrazole ring symmetry is close to C(2v), which suggests strong charge delocalization in the N-C-N fragment of the ring. There are classical hydrogen bonds in the structure which are responsible for the formation of two-membered aggregates.
RESUMO
In the title compound, alternatively named 5,5'-diphenyl-2,2'-methyleneditetrazole, C(15)H(12)N(8), the dihedral angles between the tetrazole and benzene rings in the two 5-phenyltetrazole fragments are 2.45 (6) and 10.01 (9) degrees. There is weak intermolecular C[bond]H...N hydrogen bonding involving the H atoms of the methylene groups, which is responsible for the formation of two-membered aggregates. C[bond]H...pi interactions in the crystal structure are discussed.
RESUMO
The title compound, [CuCl(2)(C(5)H(11)N(5))], is the first structurally characterized molecular chelate complex involving an alpha-aminoalkyltetrazole. There are two complex molecules in the asymmetric unit. The ligand molecules are bidentate. Both Cu atoms reveal rather distorted square-planar coordinations. The complex molecules are linked together by van der Waals interactions only.