Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Dalton Trans ; 50(18): 6245-6255, 2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-33876177

RESUMO

Reaction of (2,3,9,10,16,17,23,24-octabutylphthalocyaninato)lanthanide(iii) acetylacetonates (BuPcLn(acac), 1a-c, Ln = Lu (a), Eu (b), La (c)) with a tetrakis(5,7-bis(4-tert-butylphenyl)-6H-1,4-diazepino)[2,3-b,g,l,q]porphyrazine ligand (tBuPhDzPzH2, 2) produced sandwich compounds (tBuPhDzPz)Ln(BuPc) (3a-c), which represent the first heteroleptic double-deckers incorporating both Pc and DzPz decks. A combination of high-resolution mass spectrometry, UV-Vis/NIR, MCD, and 1H NMR spectroscopy, and square-wave voltammetry provided unambiguous characterization of target complexes 3 indicating that their spectral and electrochemical properties are generally intermediate with respect to their homoleptic relatives. Based on the data of solution-state 1H-1H NMR (COSY, NOESY) correlation spectroscopy supported by DFT calculations, a dimerization tendency of compounds 3 proportional to the Ln(iii) ion size was found. The spectroelectrochemical study of 3 and the corresponding homoleptic double-deckers revealed a pronounced tendency to aggregation of the one-electron oxidized forms of DzPz-containing double-decker complexes compared to homoleptic Pc2Ln compounds.

2.
Bioorg Med Chem Lett ; 30(16): 127351, 2020 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-32631549

RESUMO

A series of new 5-alkynyl-substituted uracil and uridine derivatives were synthesised via palladium-catalysed Sonogashira cross-coupling reaction of 5-bromo-pyrimidine base with terminal acetylenes with good yields in DMF at room temperature. All obtained compounds were tested for antimycobacterial activity against Mycobacetrium bovis and Mycobacterium tuberculosis (H37Ra) at concentrations of 1-100 µg/ml using MABA test. Obtained results revealed that most of tested uracil derivatives exhibited high antimycobacterial activity (MIC50 = 1.1-19.2 µg/ml) in comparison with therapeutic agents such as rifampicin, isoniazid and d-cycloserine, excluding compounds having alkyl substituent at triple alkyne bond.


Assuntos
Antituberculosos/farmacologia , Mycobacterium bovis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Uracila/farmacologia , Antituberculosos/síntese química , Antituberculosos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Uracila/análogos & derivados , Uracila/química
3.
Dalton Trans ; 48(35): 13413-13422, 2019 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-31433418

RESUMO

Novel heteroleptic Er(iii) and Yb(iii) naphthalocyaninato-phthalocyaninates containing an octa-phenyl or octa-phenoxysubstituted naphthalocyanine deck were synthesised and identified by 1H NMR, EPR and high resolution MALDI-TOF/TOF mass spectrometry. Direct synthesis of novel homoleptic Yb(iii) bis (octa-phenylnaphthalocyaninate) was carried out. Downfield lanthanide induced shifts of the aromatic protons in target compounds were observed compared with the corresponding diamagnetic Lu(iii) complexes. In the near-IR absorption spectra, an increase in ionic radius from Lu(iii) to Er(iii) resulted in a bathochromic shift of the intervalence band up to 1473 nm. This work presents the first experimental EPR study of Yb(iii) bis naphthalocyaninate, where a set of magnetic parameters and properties (including spin, magnitude and sign of magnetic anisotropy parameter D, increased splitting in a crystal field, ferromagnetic f-π interaction etc.) were determined and interpreted by both EPR and SQUID techniques and supported by theoretical considerations.

4.
Spectrochim Acta A Mol Biomol Spectrosc ; 205: 335-340, 2018 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-30036802

RESUMO

Direct metallation of 2-hydroxyphthalocyanine J-type slipped-cofacial dimeric ligand by Mg, Zn, Cu, Ni and Co salts has been carried out to obtain corresponding metal complexes selectively without any noticeable dissociation or polymerization of the starting ligand. Integrated analysis of aggregation properties in the synthesized series has been conducted with the involvement of AFM microscopy, UV/Vis spectroscopy and theoretical assessment. As a result, a nonlinear relationship between absorption and concentration was found, with aggregation beginning to appear at concentrations above 3.3 × 10-5 mol L-1 with predominant formation of trimers from the dimeric molecules in THF solutions.

5.
Dalton Trans ; 47(40): 14169-14173, 2018 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-29664072

RESUMO

5,7-Substituted 1,4-diazepinoporphyrazine magnesium(ii) complexes were synthesized via Mg(ii)-alkoxide templated macrocyclization. A single crystal growth synchrotron diffraction analysis permitted what is to our knowledge the first structural characterization of a 1,4-diazepinoporphyrazine. It exists as a dimer in the solid state. In silico calculations supported by solution phase spectral studies involving a series of representative derivatives, provided insights into the factors governing dimerization of 1,4-diazepinoporphyrazines. The present 1,4-diazepinoporphyrazines serve as useful probes for understanding the determinants that guide dimer-monomer equilibria and the self-assembly of phthalocyanine derivatives.

6.
Phys Chem Chem Phys ; 19(20): 12953-12958, 2017 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-28480923

RESUMO

A new nonlinear relationship of the absorption coefficient with the concentration was proposed, allowing the calculation of the threshold concentration, which shows that there is a deviation from the Beer-Lambert law. The nonlinear model was successfully tested on a stable dimeric phthalocyanine ligand of J-type in solvents with different polarity. It was shown that deviation from the linearity is connected with a specific association of the macrocyclic molecules, which, in the case of non-polar solvents, leads to the formation of H-aggregates composed of J-type dimeric molecules. The aggregation number was estimated to be less than 1.5, which has allowed us to conduct a series of analytical experiments in a wide range of concentrations (1 × 10-6-5 × 10-4 mol L-1).

7.
Dalton Trans ; 45(30): 12041-52, 2016 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-27396712

RESUMO

A series of homoleptic bis{tetrakis(5,7-bis(4-tert-butylphenyl)-6H-1,4-diazepino)[2,3-b,g,l,q]porphyrazinato}lanthanide sandwich complexes [(tBuPh)DzPz]2Ln (Ln = Lu, Er, Dy, Eu, Nd, Ce, La) were prepared and their physicochemical properties were studied to gain insight into the nature of specific interactions in diazepinoporphyrazines. The effect of annulated diazepine moieties and the Ln ionic radius on the properties of the complexes was investigated in comparison with double-decker phthalocyanines. A combination of experimental and theoretical studies revealed the presence of two types of hydrogen bonding interactions in the metal-free porphyrazine and the corresponding sandwich complexes, namely, interligand C-H(ax)N(meso) hydrogen bonding and O-HN(Dz) ligand-water interaction. The interligand hydrogen bonding imparts high stability of the ligand dimer and the double-decker compounds in a reduced state. This work is the first comprehensive investigation into the fundamental understanding of the unusual properties of diazepine-containing macroheterocycles.

8.
Phys Chem Chem Phys ; 18(23): 15964-71, 2016 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-27241278

RESUMO

The possibility of developing new advanced optical limiters of laser radiation at 532 nm with low limiting thresholds has been demonstrated on thermally stable phthalocyanine J-type dimeric complexes of Mg, Zn, Cu, Ni, and Co. A new "threshold" model based on radiative transfer phenomena in nonlinear optical media was suggested for the exact definition of nonlinear absorption coefficient ß and optical limiting threshold Ic. This model allows the determination of the optical characteristics of the limiter in the same active material with layers of different thicknesses, as well as the use of different parameters of laser radiation, such as cross-sectional spatial profiles of the laser beam and shapes of the laser pulse over time. The maximum value of the nonlinear absorption coefficient (ß = 360 cm GW(-1)) and the lowest limiting threshold (Ic = 0.03 J cm(-2)) were estimated for a J-type zinc phthalocyanine dimer.

9.
Org Biomol Chem ; 14(3): 1138-46, 2016 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-26646741

RESUMO

A series of novel 5,7-bis(2'-arylethenyl)-6H-1,4-diazepine-2,3-dicarbonitriles was synthesized through sequential aldol condensation reactions of 1,3-diketones with diaminomaleonitrile, and the resulting 5,7-dimethyl-6H-1,4-diazepines were condensed with aromatic aldehydes. The substituents' effects on the spectral properties and conformational states of the molecules in solution were studied using 2D NMR techniques and DFT calculations. Specific intramolecular steric interactions in derivatives substituted at the C6 position were discovered and investigated in detail. Differential scanning calorimetry and thermogravimetric analyses revealed the strong dependence of the thermal stability of the newly prepared diazepinodicarbonitriles on the nature of the substituents. This offers new insight into the structure-property relationships of arylethenyl-substituted diazepine derivatives.

10.
Dalton Trans ; 44(37): 16553-64, 2015 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-26332086

RESUMO

A series of half-sandwich and sandwich-type lanthanide(III) complexes have been prepared using tetrabenzotriazaporphyrin ligands. Reaction of 27-phenyl-29H,31H-tetrabenzo[b,g,l,q][5,10,15]-triazaporphyrin (PhTBTAPH2, 1) with salts [LnX3]·nH2O (Ln = Eu (a), Lu (b); X = OAc, acac) afforded the single- and homoleptic double-deckers (PhTBTAP)LnOAc (2) and (PhTBTAP)2Ln (3) respectively. Heteroleptic double-decker compounds (PhTBTAP)LnPc (4a,b) were obtained upon interaction of 1 with the corresponding Ln mono(phthalocyaninates). An unexpected formation of partially and completely dephenylated co-products 5 and 6 has been detected in the synthesis of sandwich 3, while the possibility of the dearylation of the half-sandwich compound 2 has been demonstrated as well. A more predictable yet firstly observed formation of the triple-decker compound (PhTBTAP)3Eu2 (7) has also been found. Structural studies of 3 supported by 1H NMR spectra, XRD analysis and DFT theoretical calculations reveal that the Eu complex 3a is formed as a single isomer, while the lutetium compound 3b represents an inseparable mixture of two rotational isomers with virtually identical spectral characteristics. The double-decker compounds 3 and 4 reveal intrinsic UV-Vis/NIR absorption as well as peculiar electrochromic behavior. The heteroleptic derivatives 4 generally show intermediate spectral and electrochemical properties with respect to their homoleptic relatives.

11.
Dalton Trans ; 44(17): 7973-81, 2015 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-25826576

RESUMO

Novel heteroleptic naphthalo-phthalocyaninates of lutetium possessing a symmetrical substituted naphthalocyanine deck were synthesized on the basis of two preformed synthetic blocks: naphthalocyanine ligand and lutetium phthalocyaninates. The compounds obtained were characterized by (1)H NMR and high-resolution MALDI-TOF/TOF mass spectrometry. The correlation between the nature of the substituents and the spectral properties of the target complexes was determined by the introduction of electron-donating (aryl-, aryloxy-) or electron-withdrawing (chloro-) substituents into the phthalocyanine deck. In addition, the nature of peripheral substituents was shown not to affect drastically the phthalocyanine conductivity and activation energy. Conductivity properties depend on thin film morphology which, in turn, relies on intermolecular π-π interactions.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 139: 464-70, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25576944

RESUMO

Novel A3B-type 8(9),13(14),18(19)-tri-tert-butyl-2(5),4(7)-bis(4-tert-butylphenyl)tribenzo[g,l,q]-6H-1,4-diazepino[2,3-b]porphyrazine, which has high solubility in organic solvents, was obtained by template co-condensation of 2,3-dicyano-5,7-bis(4-tert-butylphenyl)-6H-1,4-diazepine and 4-tert-butylphthalonitrile. It was characterized by UV/Vis, (1)H, (13)C NMR spectroscopy, and MALDI-TOF/TOF mass spectrometry. We have demonstrated for the first time using fluorescence spectroscopy measurements and quantum-chemical calculations that the complicated UV/Vis spectrum of A3B-type tribenzodiazepinoporphyrazine is due to the formation of stable H-type aggregates.


Assuntos
Benzodiazepinas/química , Benzodiazepinas/síntese química , Modelos Moleculares , Porfirinas/química , Porfirinas/síntese química , Teoria Quântica , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Termodinâmica
13.
Dalton Trans ; 43(7): 2799-809, 2014 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-24336892

RESUMO

A series of novel phenyl-substituted planar and sandwich-type complexes of Eu, Er and Lu with phthalo and naphthalocyanine ligands was obtained. A successful synthesis of dinaphthalocyanines from the ligand is described. A selective synthetic approach to the phenyl-substituted triphthalocyanine complexes from the ligand and acetylacetonate salts of lanthanides was developed. Correlations between the ionic radii of the central metal and absorption maxima were obtained for sandwich-type complexes. It was found that intervalence (IV) bands for dinaphthalocyanine complexes were red-shifted about 200 nm in comparison with corresponding diphthalocyanines, reaching 1797 nm for the Eu complex. The electrochemical behaviour of planar and sandwich-type Lu complexes was investigated. For the first time a spectroelectrochemical study of multistep reduction and oxidation processes for a triple-decker complex was carried out using the example of the triphthalocyanine of Lu. The structures of the compounds obtained were determined by (1)H NMR and high resolution MALDI TOF/TOF. The first single-crystal structure for an aryl-substituted double-decker complex was described using the example of the diphthalocyanine of Lu, showing the presence of intramolecular π-π interactions between phenyl groups.


Assuntos
Raios Infravermelhos , Elementos da Série dos Lantanídeos/química , Compostos Organometálicos/química , Compostos Organometálicos/síntese química , Análise Espectral , Absorção , Técnicas de Química Sintética , Eletroquímica , Modelos Moleculares , Conformação Molecular
14.
Dalton Trans ; 42(34): 12083-6, 2013 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-23863969

RESUMO

The first sandwich-type complexes have been prepared for tetrabenzotriazaporphyrin ligands. The compounds reveal intrinsic UV-Vis/NIR absorption as well as peculiar electrochromic behavior. The heteroleptic (tetrabenzotriazaporphyrinato)(phthalocyaninato) lutetium derivative shows intermediate spectral and electrochemical properties with respect to homoleptic relatives.


Assuntos
Complexos de Coordenação/química , Indóis/química , Lutécio/química , Pirróis/química , Isoindóis , Ligantes , Oxirredução , Porfirinas/química , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta
15.
Chemistry ; 18(29): 9046-55, 2012 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-22714784

RESUMO

Phthalocyanine compounds of novel type based on a bridged bis-ligand, denoted "intracavity" complexes, have been prepared. Complexation of clamshell ligand 1,1'-[benzene-1,2-diylbis(methanediyloxy)]bis[9(10),16(17),23(24)-tri-tert-butylphthalocyanine] ((clam,tBu)Pc(2)H(4), 1) with lanthanide(III) salts [Ln(acac)(3)]⋅n H(2)O (Ln = Eu, Dy, Lu; acetylacetonate) led to formation of double-deckers (clam,tBu)Pc(2)Ln (2 a-c). Formation of high molecular weight oligophthalocyanine complexes was demonstrated as well. The presence of an intramolecular covalent bridge affecting the relative arrangement of macrocycles was shown to result in specific physicochemical properties. A combination of UV/Vis/NIR and NMR spectroscopy, MALDI-TOF mass-spectrometry, cyclic voltammetry, and spectroelectrochemistry provided unambiguous characterization of the freshly prepared bis-phthalocyanines, and also revealed intrinsic peculiarities in the structure-property relationship, which were supported by theoretical calculations. Unexpected NMR activity of the paramagnetic dysprosium complex 2 b in the neutral π-radical form was observed and examined as well.


Assuntos
Indóis/química , Indóis/síntese química , Elementos da Série dos Lantanídeos/química , Eletroquímica , Isoindóis , Ligantes , Espectroscopia de Ressonância Magnética , Estrutura Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...