Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 6): 804-807, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31391970

RESUMO

The mol-ecule of the title Schiff base compound, C14H13N3O3·H2O, displays a trans configuration with respect to the C=N bond. The dihedral angle between the benzene and pyridine rings is 29.63 (7)°. The crystal structure features inter-molecular N-H⋯O, C-H⋯O, O-H⋯O and O-H⋯N hydrogen-bonding inter-actions, leading to the formation of a supramolecular framework. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from H⋯H (37.0%), O⋯H/H⋯O (23.7%)), C⋯H/H⋯C (17.6%) and N⋯H/H⋯N (11.9%) inter-actions. The title compound has also been characterized by frontier mol-ecular orbital analysis.

3.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 4): 451-455, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31161055

RESUMO

The title mol-ecular salt, C10H13N2 +·C2H3O2 -·0.5H2O, crystallized with four 2-(1H-indol-3-yl)ethanaminium cations (A, B, C and D) and four acetate anions in the asymmetric unit, together with two water mol-ecules of crystallization. Each cation is linked to an anion by a C-H⋯π inter-action. The alkyl-aminium side chains have folded conformations, with N-C-C-C torsion angles of -58.5 (3), 59.5 (3), -64.6 (3) and -56.0 (3)° for cations A, B, C and D, respectively. In the crystal, the cations and anions are liked by N-H⋯O and C-H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. The chains are linked by the water mol-ecules via Owater-H⋯O and N-H⋯Owater hydrogen bonds, forming layers lying parallel to the bc plane. The overall inter-molecular inter-actions were investigated using Hirshfeld surfaces analysis.

4.
Acta Crystallogr E Crystallogr Commun ; 75(Pt 3): 324-327, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30867941

RESUMO

The title Schiff base compound, C14H9BrCl2N2O, displays a trans or E configuration with respect to the C=N bond, with a dihedral angle 15.7 (2)° formed between the benzene rings. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen bonds, forming chains along [001] which enclose R 1 2(6) loops. The inter-molecular inter-actions were investigated by Hirshfeld surfaces analysis and two-dimensional fingerprint plots. The DFT-B3LYP/6-311 G++(d,p) method was used to determine the HOMO-LUMO energy levels.

5.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 10): 1500-1503, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30319810

RESUMO

The title Schiff base compound, C15H13BrN2O2, displays an E configuration with respect to the C=N double bond, which forms a dihedral angle of 58.06 (9)° with the benzene ring. In the crystal, the mol-ecules are linked into chains parallel to the b axis by N-H⋯O and C-H⋯O hydrogen bonds, giving rise to rings with an R 2 1(6) graph-set motif. The chains are further linked into a three-dimensional network by C-H⋯π inter-actions. A Hirshfeld surface analysis indicates that the most important contributions to the crystal packing are from C⋯H (33.2%), H⋯H (27.7%), Br⋯H/H⋯Br (14.2%) and O⋯H/H⋯O (13.6%) inter-actions. The title compound has also been characterized by frontier mol-ecular orbital analysis.

6.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 8): 1079-1082, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-30116566

RESUMO

The title Schiff base compound, C17H16N2O6, has an E configuration with respect to the C=N bond, with a dihedral angle between the two benzene rings of 31.90 (12)°. There is an intra-molecular O-H⋯Onitro hydrogen bond present forming an S(6) ring motif. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming inversion dimers enclosing an R22(4) ring motif. The dimers are linked about an inversion centre by pairs of C-H⋯O hydrogen bonds, which enclose R22(22) loops, forming chains propagating along the [10] direction. Hirshfeld surface analysis and fingerprint plots show enrichment ratios for the H⋯H, O⋯H and C⋯H contacts, indicating a high propensity of such inter-actions in the crystal. Both the nitro group and the CH3-CH2-O- group are positionally disordered.

7.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 2): 119-123, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29850036

RESUMO

The mol-ecule of the title Schiff base, C8H8BrN3OS·C2H6OS, which crystallizes as a di-methyl sulfoxide (DMSO) monosolvate, displays an E configuration with respect to the C=N bond, with a dihedral angle of 14.54 (11)° between the benzene ring and the mean plane of the N-N-C(N)=S unit. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains propagating along the b-axis direction. Within the chains there are R23(11) ring motifs, which are reinforced by C-H⋯ODMSO hydrogen bonds enclosing secondary R12(6) and R23(9) loops. The chains are linked by O-Hhydrox-yl⋯S hydrogen bonds, forming layers parallel to (011). Inversion-related layers are linked by short Br⋯Br inter-actions [3.5585 (5) Å], forming slabs parallel to (011). The inter-molecular inter-actions have been investigated using Hirshfeld surface studies and two-dimensional fingerprint plots. The crystal structure of the unsolvated form of the title compound has been reported previously [Kargar et al. (2010). Acta Cryst. E66, o2999], and its solid-state structure is compared with that of the title solvated form.

8.
Acta Crystallogr E Crystallogr Commun ; 74(Pt 5): 656-659, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29850085

RESUMO

In the crystal structure of the title salt, C6H10N3O+·C7H4ClO2-, the dihedral angle between the pyrimidine ring of the 2-amino-4-meth-oxy-6-methyl-pyrimidine cation and the the benzene ring of the 2-chloro-benzoate anion is 2.2 (1)°. In the anion, the benzene ring forms a dihedral angle of 8.5 (2)° with the carboxyl group. The pyrimidine N atom of the cation is protonated and the meth-oxy substituent is essentially coplanar with the parent ring. The protonated N atom and the N atom of the 2-amino group are hydrogen bonded to the 4-chloro-benzoate anion through a pair of N-H⋯Ocarbox-yl hydrogen bonds, forming an R22(8) ring motif linked through a centrosymmetric R24(8) ring motif, resulting in a pseudo-tetra-meric DDAA array. These units are linked through inter-molecular meth-oxy C-H⋯Cl hydrogen bonds into ribbon-like chains extending along the c-axis direction. The crystal structure also features π-π stacking inter-actions between the rings in the cation and anion [minimum ring centroid separation = 3.7707 (12) Å].

9.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 10): 1595-1598, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29250389

RESUMO

In the title mol-ecular salt, 2C6H10N3O+·C8H4O42-, the N atom of each of the two 2-amino-4-meth-oxy-6-methyl-pyrimidine mol-ecules lying between the amine and methyl groups has been protonated. The dihedral angles between the pyrimidine rings of the cations and the benzene ring of the succinate dianion are 5.04 (8) and 7.95 (8)°. Each of the cations is linked to the anion through a pair of N-H⋯O(carboxyl-ate) hydrogen bonds, forming cyclic R22(8) ring motifs which are then linked through inversion-related N-H⋯O hydrogen bonds, giving a central R24(8) motif. Peripheral amine N-H⋯O hydrogen-bonding inter-actions on either side of the succinate anion, also through centrosymmetric R22(8) extensions, form one-dimensional ribbons extending along [211]. The crystal structure also features π-π stacking inter-actions between the aromatic rings of the pyrimidine cations [minimum ring centroid separation = 3.6337 (9) Å]. The inter-molecular inter-actions were also investigated using Hirshfeld surface studies and two-dimensional fingerprint images.

10.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 9): 1305-1307, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28932461

RESUMO

In the title mol-ecular salt, C6H10N3O+·C7H5O3-, the cation is protonated at the N atom lying between the amine and methyl substituents and the dihedral angle between the carboxyl group and its attached ring in the anion is 4.0 (2)°. The anion features an intra-molecular O-H⋯O hydrogen bond, which closes an S(6) ring. The cation and anion are linked by two N-H⋯O hydrogen bonds [R22(8) motif] to generate an ion pair in which the dihedral angle between the aromatic rings is 8.34 (9)°. Crystal symmetry relates two ion pairs bridged by further N-H⋯O hydrogen bonds into a tetra-meric DDAA array. The tetra-mers are linked by pairs of C-H⋯O hydrogen bonds to generate [100] chains. Hirshfeld surface and fingerprint plot analyses are presented.

11.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 7): 1029-1032, 2017 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-28775875

RESUMO

The structure of the title Schiff base, C16H17N3O, displays a trans configuration with respect to the C=N double bond, with a dihedral angle of 14.98 (9)° between the benzene rings. In the crystal, mol-ecules are linked by N-H⋯O and C-H⋯O hydrogen-bonding inter-actions, giving sheets extending across the (001) plane. Hirshfeld surface analysis gave fingerprint plots showing enrichment ratios for H⋯H, O⋯H, N⋯H and C⋯H contacts compared to C⋯C, N⋯N and C⋯N contacts, indicating a high propensity for H⋯H interactions to form in the crystal.

12.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 6): o376-7, 2015 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-26090174

RESUMO

In the crystal of the title mol-ecular salt, C7H9N6O(+)·NO3 (-), the cations and anions are linked via N-H⋯O and O-H⋯O hydrogen bonds, forming sheets parallel to (100). Within the sheets there are numerous hydrogen-bonding ring motifs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...