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1.
Heliyon ; 8(7): e09943, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35880001

RESUMO

Five zinc(II) coordination compounds, [ZnCl2(isn)2] (1), [ZnBr2(isn)2] (2), [Zn(NO3)2(H2O)(isn)2] (3), [Zn(CH3COO)2(isn)]2 (4) and [Zn(isn)4(H2O)2](ClO4)2 (5) (isn = isonicotinamide), were prepared by the reactions of the isonicotinamide (pyridine-4-carboxamide, isn) and corresponding zinc(II) salts. Their crystal structures were determined by the single-crystal X-ray diffraction method. The coordination environment of zinc(II) is tetrahedral in the compounds containing small halide anions (chloride, bromide), 1 and 2. An expansion of the zinc(II) coordination environment to the octahedral is observed in the presence of the monodentate and bridging nitrate ions in 3. The coordination environments of both zinc(II) ions in dimeric acetate complex 4 is also enlarged in the comparison with 1 and 2, one zinc(II) ion being octahedrally coordinated and the other being pentacoordinated. The zinc(II) ion in 5 also reaches higher coordination environment (octahedral), which is enabled by binding of additional water molecules, since the perchlorate ion is uncoordinated. The supramolecular amide-amide homosynthon R 2 2 ( 8 ) is preserved in the presence of halide, nitrate and acetate ions (1-4), but it is completely disrupted in the crystal packing of 5 due to the presence of the bulky perchlorate anion. Spectroscopic analysis of compounds 1-5 was performed by IR spectroscopy in the solid state and by 13C NMR spectroscopy in the DMSO solutions. The NMR data support a complete decomposition of 3 in the DMSO solution, but 1, 2, 4 and 5 remain unchanged in the solution. Thermal properties of the coordination compounds were also investigated by TGA and DSC methods.

2.
Molecules ; 26(16)2021 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-34443586

RESUMO

Three new mercury(II) coordination compounds, {[HgCl(pic)]}n (1), [HgCl(pic)(picH)] (2), and [HgBr(pic)(picH)] (3) (picH = pyridine-2-carboxylic acid, picolinic acid) were prepared by reactions of the corresponding mercury(II) halides and picolinic acid in an aqueous (1) or alcohol-methanol or ethanol (2 and 3) solutions. Two different types of coordination compounds were obtained depending on the solvent used. The crystal structures were determined by the single-crystal X-ray structural analysis. Compound 1 is a one-dimensional (1-D) coordination polymer with mercury(II) ions bridged by chelating and bridging N,O,O'-picolinate ions. Each mercury(II) ion is four-coordinated with a bidentate picolinate ion, a carboxylate O atom from the symmetry-related picolinate ion and with a chloride ion; the resulting coordination environment can be described as a highly distorted tetrahedron. Compounds 2 and 3 are isostructural mononuclear coordination compounds, each mercury(II) ion being coordinated with the respective halide ion, N,O-bidentate picolinate ion, and N,O-bidentate picolinic acid in a highly distorted square-pyramidal coordination environment. Compounds 1-3 were characterized by IR spectroscopy, PXRD, and thermal methods (TGA/DSC) in the solid state and by 1H and 13C NMR spectroscopy in the DMSO solution.

3.
Inorg Chem ; 58(24): 16445-16457, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31774277

RESUMO

Metal complexes of iminodiacetamide (imda) ligands and metal ions Zn(II), Cu(II), Ni(II), and Co(II) were prepared using eight imda ligands (L1-L8) substituted with groups of different steric and electronic properties on the central amine N atom (H atom, methyl, isopropyl, and benzyl) and the para position of the phenyl rings (nitro and dimethylamino). The effect of these substituents on the stoichiometry (ML and ML2), geometry, and stereochemistry (mer, trans-fac, cis-fac) of the complexes was studied in the solid state, in solution, and by density functional theory calculations. Single-crystal and powder X-ray diffraction, thermogravimetry, and IR spectroscopy showed that in the solid state imda ligands preferentially form trans-fac ML2 complexes, with the exception of the cis-fac complex 7Zn. NMR spectroscopy of diamagnetic Zn(II) and paramagnetic Co(II) complexes revealed the formation of both ML and ML2 complexes in solution, which was also confirmed by UV-vis titrations. Variable-temperature NMR was used to study the effect of the substituent on the central amine N atom on the Zn-N bond strength and nitrogen inversion. The relative stabilities of the isomers were rationalized by computations and the optimized structures used for geometry analysis.

4.
Clin Respir J ; 12(2): 398-403, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27402309

RESUMO

INTRODUCTION: Nocturnal symptoms are common and important in both asthma and COPD but the relationship between sleep quality and diseases' characteristics has not been fully studied. OBJECTIVE: To compare sleep quality and daytime sleepiness in asthma and COPD patients and to explore its relation to diseases' characteristics. METHODS: In this cross-sectional study, we examined 217 consecutive asthma and COPD patients who underwent pulmonary function tests at The Center for Pathophysiology of Breathing and Sleep Medicine of The Institute for Pulmonary Diseases of Vojvodina, Sremska Kamenica, Serbia between July 2014 and January 2015. All patients completed Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). RESULTS: Study included 117 patients with asthma, 100 patients with COPD, and 102 healthy controls. There was no difference in PSQI and ESS between patients with asthma and COPD (4.9 ± 3.9 vs 5.8 ± 4.3, P = .09 and 4.8 ± 3.4 vs 4.7 ± 3.6, P = .69, respectively). PSQI and ESS did not correlate with lung function parameters. Patients with uncontrolled asthma had higher PSQI scores (uncontrolled 7.0 ± 3.7 vs partially controlled 4.6 ± 3.1 vs controlled 3.2 ± 3.7, P < .001). PSQI scores were higher in COPD group D and B compared to A and C (group D 6.9 ±4.6 vs B 6.8 ± 4.1 vs A 2.9 ± 1.3 vs C 3.1 ± 3.9, P < .001). Compared to asthma, COPD patients had longer sleep latency and used sleep regulating medications more often. CONCLUSIONS: There is no difference in sleep quality and level of daytime sleepiness between patients with asthma and COPD. Poor sleep quality is related to level of asthma control and is associated with COPD groups B and D.


Assuntos
Asma/epidemiologia , Distúrbios do Sono por Sonolência Excessiva/epidemiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Transtornos do Sono-Vigília/epidemiologia , Sono/fisiologia , Adulto , Idoso , Asma/fisiopatologia , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Testes de Função Respiratória/métodos , Sérvia/epidemiologia , Índice de Gravidade de Doença
5.
Talanta ; 150: 37-45, 2016 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26838379

RESUMO

A novel quantitative prediction and variable selection method called interval ridge regression (iRR) is studied in this work. The method is performed on six data sets of FTIR, two data sets of UV-vis and one data set of DSC. The obtained results show that models built with ridge regression on optimal variables selected with iRR significantly outperfom models built with ridge regression on all variables in both calibration (6 out of 9 cases) and validation (2 out of 9 cases). In this study, iRR is also compared with interval partial least squares regression (iPLS). iRR outperfomed iPLS in validation (insignificantly in 6 out of 9 cases and significantly in one out of 9 cases for p<0.05). Also, iRR can be a fast alternative to iPLS, especially in case of unknown degree of complexity of analyzed system, i.e. if upper limit of number of latent variables is not easily estimated for iPLS. Adulteration of hempseed (H) oil, a well known health beneficial nutrient, is studied in this work by mixing it with cheap and widely used oils such as soybean (So) oil, rapeseed (R) oil and sunflower (Su) oil. Binary mixture sets of hempseed oil with these three oils (HSo, HR and HSu) and a ternary mixture set of H oil, R oil and Su oil (HRSu) were considered. The obtained accuracy indicates that using iRR on FTIR and UV-vis data, each particular oil can be very successfully quantified (in all 8 cases RMSEP<1.2%). This means that FTIR-ATR coupled with iRR can very rapidly and effectively determine the level of adulteration in the adulterated hempseed oil (R(2)>0.99).


Assuntos
Fraude , Informática/métodos , Óleos de Plantas/química , Análise Multivariada , Análise de Regressão , Fatores de Tempo
6.
Srp Arh Celok Lek ; 143(5-6): 279-83, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26259399

RESUMO

INTRODUCTION: The splenic involvement is common in sarcoidosis, but its real frequency is still obscure depending doubtless on the method of splenomegaly detection. Splenomegaly may be accompanied with pain or anemia, leucopenia and thrombocytopenia. OBJECTIVE: The aim of this study was to investigate the frequency of splenomegaly related to clinical characteristics of sarcoidosis and to solve the dilemma--whether to introduce medicaments, and when to perform splenectomy. METHODS: The method of the study is a retrospective and prospective analysis of the patients'material. RESULTS: The study included 540 patients with sarcoidosis in a 20-year period. Of them, 26% had splenomegaly detected by computerized tomography screening. Splenomegaly was more frequently registered in the patients with a longer history of sarcoidosis (38%), as compared to those with a shorter history of the disease (23%) (p < 0.05). Splenomegaly was more frequently registered in the patients with other extrapulmonary lesions detected (33%) than in those who had no extrapulmonary manifestations of sarcoidosis (17%) (p < 0.01). Indications, possible benefits and complications of splenectomy were analysed in 11 sarcoidosis patients undergoing this intervention for various reasons, of which the follow-up period ranged from one to 20 years. CONCLUSION: Splenomegaly was more frequent in chronic cases or in the patients with established sarcoid lesions of other extrapulmonary organs.The primary treatment of uncomplicated symptomatic splenic sarcoidosis includes medicamentous therapy. Occasionally, splenectomy is required. Prognostically, splenomegaly indicates an unfavorable course of the disease.


Assuntos
Sarcoidose Pulmonar/diagnóstico , Sarcoidose Pulmonar/epidemiologia , Esplenomegalia/diagnóstico , Esplenomegalia/epidemiologia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Sarcoidose Pulmonar/terapia , Esplenomegalia/terapia
7.
Acta Chim Slov ; 62(2): 328-36, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26085414

RESUMO

Four new Zn(II) and Cd(II) picolinamide (pia) complexes with cyanate and azide, e.g. [Zn(OCN)2(pia)2] (1), [Cd(OCN)2(pia)2]n (2), [Zn(N3)2(pia)2] (3) and [Cd(N3)2(pia)2]n·nH2O (4), have been prepared and characterized by IR and NMR spectroscopy, and thermal (TG/DTA) methods. For the compounds 1 and 3 X-ray analysis revealed mononuclear molecular structure with octahedral N4O2 environment around the zinc(II) center with cis-arrangement of ligands. Only in 1 the amide head-to-head supramolecular motifs, represented by an R2(2) (8) designator, are observed, while in 3 none of the typical amide motifs were found. While the IR data suggests the polymeric structures for 2 and 4 in the solid state, all the NMR spectra agree with the monomeric structure of the compounds in the solution.

8.
Expert Rev Med Devices ; 10(5): 685-95, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23972074

RESUMO

Endobronchial ultrasound (EBUS) in recent years has become a routine diagnostic procedure in bronchology. Linear EBUS shows high diagnostic yield in evaluation of mediastinal lymph nodes. It is mainly used for nodal evaluation in lung cancer, but has also proven to be efficient in diagnostic evaluation of mediastinal masses. This technique has been shown to be complementary to mediastinoscopy. In combination with PET and rapid on site cytology (ROSE), the diagnostic yield of EBUS is significantly higher. Radial EBUS is used for diagnosis of peripheral lung lesions. This technique facilitates evaluation of bronchial wall in central lung cancer lesions, enabling differentiation between early and invasive lung cancer. The diagnostic yield of radial EBUS in the diagnostics of peripheral lung lesions is high, reducing the number of diagnostic thoracotomies. The application of miniature radial EBUS probes, together with guiding sheaths and other guiding accessories, allow the access to smaller and more peripheral lung lesions. In addition, EBUS bronchoscopy can be utilized for the placement of brachytherapy catheters, or evaluation of the distal bronchi in order to chose between different therapeutic bronchoscopic techniques for desobstruction. An experienced bronchoscopist, availability of ROSE and additional guiding devices might be necessary to accomplish the best possible results of EBUS bronchoscopy.


Assuntos
Broncoscopia/instrumentação , Endossonografia/instrumentação , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Ensaios Clínicos como Assunto , Humanos , Estadiamento de Neoplasias
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 101: 273-82, 2013 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23103469

RESUMO

Two cobalt(II) complexes with 3-hydroxypicolinic acid (3-hydroxypyridine-2-carboxylic acid, 3-OHpicH), trans-[Co(3-OHpic)2(py)2] (2) and cis-[Co(3-OHpic)2(4-pic)2] (3) (py=pyridine; 4-pic=4-picoline or 4-methylpyridine), previously synthesized and characterized by X-ray diffraction, are here studied by Raman and mid-infrared spectroscopy with the help from the corresponding DFT vibrational calculations using B3LYP/6-311G(d,p) computational model. Intramolecular O-H⋯O hydrogen bond appears in both complexes 2 and 3, while weak C-H⋯O hydrogen bonds assemble molecules of 2 or 3 into 3D architecture. A complete presentation of all Raman, infrared and theoretical results is given for complex 3. The measured spectra are shown, relative intensities and bandwidths are discussed and the assignment of vibrational bands is given on the basis of the DFT calculations. The calculated spectra agree very well with the presented experimental findings, thanks to the suitable grouping of modes. The same vibrational calculations also reveal insignificant influence of H→CH3 substitution for the spectroscopic characterization of the complex. A careful study of differences between calculated and observed wavenumbers suggests that modified single-factor scaling is actually better than the classic multi-factor scaling approach.


Assuntos
Cobalto/química , Complexos de Coordenação/química , Ácidos Picolínicos/química , Modelos Moleculares , Teoria Quântica , Espectrofotometria Infravermelho , Análise Espectral Raman , Difração de Raios X
10.
Acta Crystallogr C ; 65(Pt 9): m361-6, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19726853

RESUMO

The title compounds, trans-diaquabis(nitrato-kappaO)bis(pyridine-4-carboxamide-kappaN(1))copper(II), [Cu(NO(3))(2)(C(6)H(6)N(2)O)(2)(H(2)O)(2)], (I), and trans-diaquatetrakis(pyridine-4-carboxamide-kappaN(1))copper(II) bis(perchlorate), [Cu(C(6)H(6)N(2)O)(4)(H(2)O)(2)](ClO(4))(2), (II), are composed of mononuclear coordination entities involving Cu(II) ions and isonicotinamide. In (I), the centrosymmetric tetragonally distorted octahedral copper(II) environment contains trans-related isonicotinamide and water molecules in the equatorial plane and two nitrate ions occupying the axial sites. In (II), the equatorial plane of the C(2)-symmetric distorted octahedron is built up of four isonicotinamide ligands, while water molecules occupy the axial positions. The complex molecules of (I) and (II) are linked into three-dimensional supramolecular frameworks by O-H...O and N-H...O hydrogen bonds. The nitrate and perchlorate ions are building blocks that disturb the robust R(2)(2)(8) amide supramolecular motif commonly found in crystal structures of copper-isonicotinamide complexes.


Assuntos
Ânions/química , Niacinamida/química , Nitratos/química , Compostos Organometálicos/química , Percloratos/química , Cobre , Cristalografia por Raios X , Ligação de Hidrogênio , Modelos Moleculares
11.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 2): m311-2, 2008 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-21201283

RESUMO

The title compound, [Ni(N(3))(2)(C(6)H(6)N(2)O)(2)], was obtained as the first crystalline product from the reaction of Ni(NO(3))(2)·6H(2)O, picolinamide and NaN(3) in aqueous media. After a few days in the mother liquor, crystals of the cis isomer transformed into the trans isomer [Dakovic & Popovic (2007 ▶). Acta Cryst. C63, m507-m509]. The Ni atom exhibits a distorted octa-hedral environment and contains two azide ions and two planar N,O-chelating picolinamide ligands, all cis related. The dihedral angle between the two chelate rings is 82.43 (7)°. Pairs of mol-ecules are linked by N-H⋯N hydrogen bonds into cyclic R(2) (2)(16) dimers, which are further packed into a three-dimensional framework by C(6) and C(8) chains by N-H⋯N hydrogen bonds.

12.
Acta Crystallogr C ; 63(Pt 12): m557-9, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18057593

RESUMO

In the title compound, [Hg(NO3)(C6H6N2O)2]NO3, the Hg(II) atom is five-coordinate. The distorted square-pyramidal mercury(II) coordination environment is achieved by two N,O-bidentate picolinamide ligands, with one O-monodentate nitrate ion in the apical position. A seven-coordinate extended coordination environment is completed by two additional weak Hg...O interactions, one from the coordinated nitrate ion and one from the other nitrate ion, to give seven-coordination. The molecules are linked into a two-dimensional network by N-H...O hydrogen bonds.


Assuntos
Compostos de Mercúrio/química , Nitratos/química , Compostos Organomercúricos/química , Compostos Organomercúricos/síntese química , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Estrutura Molecular
13.
Acta Crystallogr C ; 63(Pt 12): m615-7, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18057610

RESUMO

The title compound, [Co(C7H6NO2)2(H2O)4] x 4 H2O, contains a Co(II) ion lying on a crystallographic inversion centre. The Co(II) ion is octahedrally coordinated by two 6-methylpyridine-3-carboxylate ligands in axial positions [Co-O = 2.0621 (9) A] and by four water molecules in the equatorial plane [Co-O = 2.1169 (9) and 2.1223 (11) A]. There are also four uncoordinated water molecules. The 6-methylpyridine-3-carboxylate ligands are bound to the Co(II) ion in a monodentate manner through a carboxylate O atom. There is one strong intramolecular O-H...O hydrogen bond, and six strong intermolecular hydrogen bonds of type O-H...O and one of type O-H...N in the packing, resulting in a complex three-dimensional supramolecular structure.


Assuntos
Cobalto/química , Ácidos Nicotínicos/química , Compostos Organometálicos/química , Piridinas/química , Cristalografia por Raios X , Ligantes , Estrutura Molecular , Compostos Organometálicos/síntese química
14.
Acta Crystallogr C ; 63(Pt 11): m507-9, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17989466

RESUMO

In the title compound, [Ni(N(3))(2)(C(6)H(6)N(2)O)(2)], the Ni(II) atom lies on an inversion centre. The distorted octahedral nickel(II) coordination environment contains two planar trans-related N,O-chelating picolinamide ligands in one plane and two monodentate azide ligands perpendicular to this plane. Molecules are linked into a three-dimensional framework by N-H...N hydrogen bonds.


Assuntos
Níquel/química , Compostos Organometálicos/química , Ligação de Hidrogênio , Conformação Molecular
15.
Acta Crystallogr C ; 63(Pt 9): m389-91, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17762103

RESUMO

In the title compound, [Cd(C(7)H(6)NO(2))2]n, the Cd(II) ion has a distorted octahedral geometry. The 6-methylpyridine-2-carboxylate anions are perpendicular to one another and act as bidentate and bridging ligands. Two carboxylate O atoms bridge the Cd(II) ions, forming centrosymmetric dinuclear units. These units are further connected via carboxylate O atoms into a one-dimensional polymeric chain which extends in the [100] direction.


Assuntos
Cádmio/química , Compostos Organometálicos/química , Ácidos Picolínicos/química , Polímeros/química , Modelos Moleculares , Conformação Molecular
16.
Acta Crystallogr C ; 63(Pt 5): m181-3, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17478894

RESUMO

The title compound, [Cu(C(9)H(5)N(2)O(3))(2)(C(2)H(6)OS)(2)], consists of octahedrally coordinated Cu(II) ions, with the 3-oxo-3,4-dihydroquinoxaline-2-carboxylate ligands acting in a bidentate manner [Cu-O = 1.9116 (14) A and Cu-N = 2.1191 (16) A] and a dimethyl sulfoxide (DMSO) molecule coordinated axially via the O atom [Cu-O = 2.336 (5) and 2.418 (7) A for the major and minor disorder components, respectively]. The whole DMSO molecule exhibits positional disorder [0.62 (1):0.38 (1)]. The octahedron around the Cu(II) atom, which lies on an inversion centre, is elongated in the axial direction, exhibiting a Jahn-Teller effect. The ligand exhibits tautomerization by H-atom transfer from the hydroxyl group at position 3 to the N atom at position 4 of the quinoxaline ring of the ligand. The complex molecules are linked through an intermolecular N-H...O hydrogen bond [N...O = 2.838 (2) A] formed between the quinoxaline NH group and a carboxylate O atom, and by a weak intermolecular C-H...O hydrogen bond [3.392 (11) A] formed between a carboxylate O atom and a methyl C atom of the DMSO ligand. There is a weak intramolecular C-H...O hydrogen bond [3.065 (3) A] formed between a benzene CH group and a carboxylate O atom.

17.
Acta Crystallogr C ; 62(Pt 7): m272-4, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16823190

RESUMO

The title compound, [Hg(C(6)H(4)NO(2))I(C(6)H(5)NO(2))], has twofold symmetry along the Hg-I bond. The Hg(II) ion coordinates one I atom [at 2.6045 (4) Angstrom], two N and two O atoms [at 2.298 (3) and 2.481 (2) Angstrom] from one picolinate ion, and one picolinic acid molecule in a very irregular trigonal-bipyramidal coordination. The single hydroxy H atom required for chemical neutrality is both statistically (by crystal symmetry) and structurally disordered, and is involved in an intermolecular O-H...O hydrogen bond [O...O = 2.455 (4) Angstrom], connecting the molecules into one-dimensional infinite chains along the [101] direction.

18.
Acta Crystallogr C ; 61(Pt 7): m351-2, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15997063

RESUMO

In the crystal structure of the title compound, [Zn(C18H14NO2)2].C2H6O, the Zn atom displays a highly distorted octahedral coordination involving the O and N atoms of two molecules of the Schiff base 1-[N-(2-methoxyphenyl)iminomethyl]naphthalen-2(1H)-one, which acts as an O,N,O'-tridentate ligand. The ethanol molecule is bound to the methoxy group of one ligand molecule via a hydrogen bond.

19.
Acta Crystallogr C ; 61(Pt 2): o98-o100, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15695922

RESUMO

The title compound, C10H16N3+.Cl-.C2H6O, is an important intermediate in the convergent synthesis of amidine-substituted polycyclic heterocycles, a class of compounds that shows significant anticancer activity. The molecule of (I) is not planar, having a dihedral angle of 25.00 (7) degrees between the aniline and amidine (-C-NH=C=NH2) groups. The protonation of the amidine molecular fragment is accompanied by delocalized C-N bond distances of 1.320 (2) and 1.317 (2) A. The cations and chloride anions are involved in a network of hydrogen bonds, resulting in the formation of infinite chains propagating along the b direction. The chains are further grouped within the ab plane, in such a way that the structure is segregated into layers dominated by hydrophobic interactions involving N-isopropyl residues and layers dominated by N-H...Cl [N...Cl = 3.275 (2)-3.596 (2) A], O-H...Cl [O...Cl = 3.229 (3) A] and N-H...O [N...O = 2.965 (3) A] hydrogen bonds.


Assuntos
Benzamidinas/química , Cloretos/química , Benzamidinas/síntese química , Cristalografia por Raios X , Etanol/química , Ligação de Hidrogênio , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Solubilidade , Espectrofotometria Infravermelho
20.
Acta Crystallogr C ; 60(Pt 2): m44-6, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14767109

RESUMO

The title compound, [Hg(C(4)H(4)N(2)S)(C(4)H(3)N(2)S)](2)[HgBr(4)], consists of [Hg(pymt)(pymtH)](+) complex cations (pymtH is pyrimidine-2-thione) lying across twofold rotation axes in space group Fddd, with linearly coordinated mercury at an Hg-S distance of 2.357 (3) A, and [HgBr(4)](2-) anions lying at sites of 222 symmetry. The Hg atom is additionally coordinated by two N and two Br atoms, forming a 2+4 effective coordination sphere. The protonated ligand is connected via N-H.N hydrogen bonds to the neighbouring unprotonated ligand, thus forming infinite chains of cations.

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