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1.
ACS Omega ; 4(22): 19875-19879, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31788620

RESUMO

Photoisomerization of Irgacure PAG 103 followed by photocyclization and fragmentation leads to three tricyclic thieno[2,3-b]quinoline-4-carbonitrile heterocyclic compounds. The release of acid which can catalyze polymer resist modifications is indicated by the low pH of an aqueous extract. These reactions are discussed in view of possible mechanisms and how these might influence future design strategies.

2.
ChemistryOpen ; 8(9): 1204-1208, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31523608

RESUMO

The synthesis of a Cu4(OH)4 cube which is coordinated by four molecules of the dipyridyl ligand 1,6-[di(pyridin-4-yl)hex-3-ene] is reported. This compound has a trans double bond which restricts the conformational freedom of the ligand and favours coordination within a unique copper cube. The structure was solved by an X-Ray single crystal structure determination and low temperature magnetic susceptibility measurements examined its magnetic properties. The cube classification corresponds to the type I classification of Mergehenn and Haase and the short/long distribution of Cu ⋅⋅⋅ Cu separations in the cube as defined by Ruiz. The magnetic susceptibility measurements show paramagnetic behaviour down to 50 K but below this the copper cube shows weak ferromagnetic exchange interactions. The low temperature magnetic susceptibility characteristics are examined in detail then modelled and compared to other similar Cu4O4 copper cubes.

3.
ChemistryOpen ; 8(4): 457-463, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31008010

RESUMO

Two similar molecular building blocks, which both contain a hydrogen-bonded nitro group, have been prepared and crystallised. One structure has more flexibility with a butyl side chain which allows an open framework organic zeolite to form with large 10 Šdiameter pores, whereas the other structure has less flexibility with an aryl side chain and is close packed. The pore size is comparable with those of the aluminophosphate VPI-5 (12 Å). It is concluded that some flexibility in the design of the building block for porous organic molecular materials was beneficial.

4.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 2): 188-191, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28217339

RESUMO

The title compound, NaK5Cl2(S2O6)2 [systematic name: sodium penta-potassium dichloride bis-(di-thio-nate)], arose as an unexpected product from an organic synthesis that used di-thio-nite (S2O42-) ions as a reducing agent to destroy excess permanganate ions. Compared to the previous study [Stanley (1953 ▸). Acta Cryst.6, 187-196], the present tetra-gonal structure exhibits a root 2a × root 2a × c super-cell due to subtle changes in the orientations of the di-thio-nate anions. The structure can be visualized as a three-dimensional framework of [001] columns of alternating trans-NaO4Cl2 and KO4Cl2 octa-hedra cross-linked by the di-thio-nate ions with the inter-stices occupied by KO6Cl2 polyhedra to generate a densely packed three-dimensional framework. The asymmetric unit comprises two sodium ions (site symmetries 4 and -4, four potassium ions (site symmetries = -4, 4, 1 and 1), three chloride ions (site symmetries = 4, 4 and 2) and two half-di-thio-nate ions (all atoms on general positions). Both di-thio-nate ions are completed by crystallographic inversion symmetry. The crystal chosen for data collection was found to be rotationally twinned by 180° about the [100] axis in reciprocal space with a 0.6298 (13):0.3702 (13) domain ratio.

5.
Acta Crystallogr E Crystallogr Commun ; 72(Pt 5): 604-7, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-27307999

RESUMO

In the cation of the title hydrated mol-ecular salt, C6H7N2O2 (+)·Cl(-)·H2O, the six-membered ring shows unequal bond lengths consistent with delocalization of electrons over two separate 6π systems with single bonds between them. In the crystal, the components are linked by N-H⋯Cl, N-H⋯O, O-H⋯Cl and O-H⋯O hydrogen bonds, generating double layers propagating in (100).

6.
Acta Crystallogr E Crystallogr Commun ; 72(Pt 3): 407-11, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-27006818

RESUMO

The title compounds, C14H12O, (I), and C15H11BrO2, (II), were prepared and characterized as part of our studies of potential new photo-acid generators. In (I), which crystallizes in the ortho-rhom-bic space group Pca21, compared to P21/n for the previously known monoclinic polymorph [Cornella & Martin (2013 ▸). Org. Lett. 15, 6298-6301], the dihedral angle between the aromatic rings is 4.35 (6)° and the OH group is disordered over two sites in a 0.795 (3):0.205 (3) ratio. In the crystal of (I), mol-ecules are linked by O-H⋯π inter-actions involving both the major and minor -OH disorder components, generating [001] chains as part of the herringbone packing motif. The asymmetric unit of (II) contains two mol-ecules with similar conformations (weighted r.m.s. overlay fit = 0.183 Å). In the crystal of (II), both mol-ecules form carboxyl-ate inversion dimers linked by pairs of O-H⋯O hydrogen bonds, generating R 2 (2)(8) loops in each case. The dimers are linked by pairs of C-H⋯O hydrogen bonds to form [010] chains.

7.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 8): 80-3, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25249860

RESUMO

The title compound, poly[[di-aqua-bis-[1,5-bis-(pyridin-4-yl)pentane-κ(2) N:N']cadmium] bis-(perchlorate) 1,5-bis-(pyridin-4-yl)pentane ethanol mono-solvate], [Cd(C15H18N2)2(H2O)2](ClO4)2·C15H18N2·C2H6O, is a layered coordination polymer built up from highly squashed 4(4) nets in which the octa-hedral trans-CdO2N4 nodes (Cd site symmetry -1) are linked by the bifunctional ligands, forming infinite (110) sheets. The cationic sheets are charge-balanced by inter-layer perchlorate ions. A free 1,5-bis-(pyridin-4-yl)pentane mol-ecule and an ethanol mol-ecule of crystallization are also found in the inter-sheet region. A number of O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds help to consolidate the layered structure.

8.
Org Biomol Chem ; 7(8): 1633-41, 2009 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-19343250

RESUMO

Aldehydes substituted with a quaternised pyridinium or quinolinium ring have been investigated for the development of latent fingerprints. Two routes were developed to a novel in situ formed azacyanine dye. This dye might form in the fingerprint where reagents are concentrated but does not form appreciably in solution experiments as evidenced by the lack of an absorption band at 600 nm. N-Alkyl and N-aryl substituted benzimidazole-2-carboxaldehydes give stable fluorescent fingerprints.


Assuntos
Aldeídos/química , Aminoácidos/química , Dermatoglifia , Corantes Fluorescentes/química , Compostos de Piridínio/química , Compostos de Quinolínio/química , Aldeídos/síntese química , Cristalografia por Raios X , Corantes Fluorescentes/síntese química , Humanos , Estrutura Molecular , Compostos de Piridínio/síntese química , Compostos de Quinolínio/síntese química
9.
Acta Crystallogr C ; 58(Pt 10): m487-9, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12359922

RESUMO

The structure of the title compound, [Co(4)(C(9)H(3)O(6))(2)(OH)(2)(C(8)H(6)N(4))(H(2)O)(2)].2H(2)O, contains three separate species, namely the mu(5)-bridging C(9)H(3)O(6)(3-) anion, the doubly chelating and therefore mu(2)-bridging C(8)H(6)N(4) ligand (bipyrimidine, BPM), and the dihydrated diaquadihydroxy tetranuclear cationic cluster, [Co(4)(OH(-))(2)(H(2)O)(2)](6+).2H(2)O, which lies on a crystallographic centre of symmetry, as does the BPM ligand with, in this case, the centre of symmetry coincident with the midpoint of the C-C bond joining the six-membered rings. Within the cation cluster, the Co atoms of one pair are five-coordinate and those of the other six-coordinate.

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