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Ludmila S Ivashkevich

Publications and source records attributed to Ludmila S Ivashkevich.

12 recordsLinked to original sources
PubMed2006

An X-ray powder investigation of catena-poly[copper(II)-di-mu-chloro-kappa41:2Cl-mu-1,5-dimethyl-1H-tetrazole-kappa2N3:N4].

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.

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PubMed2006

Bis(1-methyl-1H-tetrazol-5-yl)diazene and two its copper(I) chloride complexes poly[[[mu-1,2-bis(1-methyl-1H-tetrazol-5-yl)diazene-kappa4N',N4:N,N4']dicopper(I)]-di-mu-chloro] and catena-poly[[chlorocopper(I)]-mu-1,2-bis(1-methyl-1H-tetrazol-5-yl)diazene-kappa4N',N4:N,N4'].

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.

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PubMed2005

Coordination polymers formed by bridging 2-substituted tetrazole ligands: poly[[dichlorocopper(II)]-di-mu2-2-propyl-2H-tetrazole-kappa2N1:N4] and poly[[dichlorocopper(II)]-di-mu2-2-allyl-2H-tetrazole-kappa2N1:N4].

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.

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PubMed2004

Bis[1,3-bis(2-methyltetrazol-5-yl-kappaN4)triazenido-kappaN2]nickel(II).

The title compound, [Ni(BMTT)2], where BMTT is 1,3-bis(2-methyltetrazol-5-yl)triazenide (C4H6N11), presents a molecular complex with tridentate ligands. The tridentate mode of the ligand is realised through the central N atom of the triazene group and two N atoms of the two tetrazole rings. The [Ni(BMTT)2] molecule is the meridional isomer, with crystallographic 4 symmetry in space group P4(2)/n. The nickel centre has a distorted octahedral environment, with two axial Ni-N bonds of 2.041 (2) A and four equatorial Ni-N bonds of 2.0739 (14) A. The molecules are linked together by van der Waals interactions only.

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PubMed2004

1-phenyl-5-(piperidinomethyl)-1H-tetrazole.

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.

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PubMed2003

Two derivatives of 5-aminotetrazole: 5-amino-1-phenyltetrazole and 5-amino-1-(1-naphthyl)tetrazole.

In the molecules of 5-amino-1-phenyltetrazole, C(7)H(7)N(5), (I), and 5-amino-1-(1-naphthyl)tetrazole, C(11)H(9)N(5), (II), the tetrazole rings and aryl fragments are not coplanar; corresponding dihedral angles are 50.58 (5) and 45.19 (7) degrees for the two independent molecules of (I), and 64.14 (5) degrees for (II). Intermolecular N-H.N hydrogen bonds between the amino groups and tetrazole N atoms are primarily responsible for formation of two-dimensional networks extending parallel to the bc plane in both compounds. The presence of the amino group has a distinct effect on the geometry of the tetrazole rings in each case.

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PubMed2003

Non-linear optical crystals of 2,2,3-trimethyl-3-(1H-1,2,3,4-tetrazol-5-yl)butanenitrile.

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.

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PubMed2003

The layered structure of poly[[di-mu-chloro-bis[chloro(2-ethyltetrazole-kappaN(4))copper(II)]]-di-mu-2-ethyltetrazole-kappa(2)N(1):N(4)].

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.

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PubMed2003

catena-poly[[tetrakis(2-allyltetrazole-kappaN4)-tetra-mu-chloro-tricopper(II)]-di-mu-chloro].

In the crystal structure of the title compound, [Cu(3)Cl(6)(C(4)H(6)N(4))(4)](n), there are three Cu atoms, six Cl atoms and four 2-allyltetrazole ligands in the asymmetric unit. The polyhedron of one Cu atom adopts a flattened octahedral geometry, with two 2-allyltetrazole ligands in the axial positions [Cu-N4 = 1.990 (2) and 1.991 (2) A] and four Cl atoms in the equatorial positions [Cu-Cl = 2.4331 (9)-2.5426 (9) A]. The polyhedra of the other two Cu atoms have a square-pyramidal geometry, with three basal sites occupied by Cl atoms [Cu-Cl = 2.2487 (9)-2.3163 (8) and 2.2569 (9)-2.3034 (9) A] and one basal site occupied by a 2-allyltetrazole ligand [Cu-N4 = 2.028 (2) and 2.013 (2) A]. A Cl atom lies in the apical position of either pyramid [Cu-Cl = 2.8360 (10) and 2.8046 (9) A]. The possibility of including the tetrazole N3 atoms in the coordination sphere of the two Cu atoms is discussed. Neighbouring copper polyhedra share their edges with Cl atoms to form one-dimensional polymeric chains running along the a axis.

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PubMed2002

Zwitterionic 5-(1-piperidiniomethyl)-1H-tetrazolide.

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.

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PubMed2002

Bis(5-phenyltetrazol-2-yl)methane.

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.

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