RESUMO
Two new Zn(II) complexes with tridentate hydrazone-based ligands (condensation products of 2-acetylthiazole) were synthesized and characterized by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy and single crystal X-ray diffraction methods. The complexes 1, 2 and recently synthesized [ZnL3(NCS)2] (L3 = (E)-N,N,N-trimethyl-2-oxo-2-(2-(1-(pyridin-2-yl)ethylidene)hydrazinyl)ethan-1-aminium) complex 3 were tested as potential catalysts for the ketone-amine-alkyne (KA2) coupling reaction. The gas-phase geometry optimization of newly synthesized and characterized Zn(II) complexes has been computed at the density functional theory (DFT)/B3LYP/6-31G level of theory, while the highest occupied molecular orbital and lowest unoccupied molecular orbital (HOMO and LUMO) energies were calculated within the time-dependent density functional theory (TD-DFT) at B3LYP/6-31G and B3LYP/6-311G(d,p) levels of theory. From the energies of frontier molecular orbitals (HOMO-LUMO), the reactivity descriptors, such as chemical potential (µ), hardness (η), softness (S), electronegativity (χ) and electrophilicity index (ω) have been calculated. The energetic behavior of the investigated compounds (1 and 2) has been examined in gas phase and solvent media using the polarizable continuum model. For comparison reasons, the same calculations have been performed for recently synthesized [ZnL3(NCS)2] complex 3. DFT results show that compound 1 has the smaller frontier orbital gap so, it is more polarizable and is associated with a higher chemical reactivity, low kinetic stability and is termed as soft molecule.
Assuntos
Teoria da Densidade Funcional , Hidrazonas/química , Hidrazonas/síntese química , Zinco/química , Catálise , Cristalografia por Raios X , Conformação Molecular , Teoria Quântica , TermodinâmicaRESUMO
Novel tetrachloridoruthenium(III) complex Na[trans-RuCl4(DMSO)(PyrDiaz)] (3) with pyridine-tethered diazenedicarboxamide PyrDiaz ligand (PyrDiaz = N1-(4-isopropylphenyl)-N2-(pyridin-2-ylmethyl)diazene-1,2-dicarboxamide) was synthesized by direct coupling of PyrDiaz with sodium trans-bis(dimethyl sulfoxide)tetrachloridoruthenate(III) (Na-[trans-Ru(DMSO)2Cl4]). Compound 3 is the analogue of the antimetastatic Ru(III) complex NAMI-A and NAMI-Pyr. Single crystal X.
Assuntos
Antineoplásicos/síntese química , Dimetil Sulfóxido/análogos & derivados , Compostos Organometálicos/química , Rutênio/química , Antineoplásicos/química , Cristalografia por Raios X , Dimetil Sulfóxido/química , Imidas/síntese química , Imidas/químicaRESUMO
Square-planar azido Ni(II) complex with condensation product of 2-(diphenylphosphino)benzaldehyde and Girard's T reagent was synthesized and its crystal structure was determined. Cytotoxic activity of the azido complex and previously synthesized isothiocyanato, cyanato and chlorido Ni(II) complexes with this ligand was examined on six tumor cell lines (HeLa, A549, K562, MDA-MB-453, MDA-MB-361 and LS-174) and two normal cell line (MRC-5 and BEAS-2B). All the investigated nickel(II) complexes were cytotoxic against all tumor cell lines. The newly synthesized azido complex showed selectivity to HeLa and A549 tumor cell lines compared to the normal cells (for A549 IC50 was similar to that of cisplatin). Azido complex interferes with cell cycle phase distribution of A549 and HeLa cells and possesses nuclease activity towards supercoiled DNA. The observed selectivity of the azido complex for some tumor cell lines can be connected with its strong DNA damaging activity.
Assuntos
Antineoplásicos/farmacologia , Benzaldeídos/química , Halogênios/química , Hidrazonas/química , Níquel/química , Antineoplásicos/química , Cristalografia por Raios X , Células HeLa , Humanos , Microscopia de Fluorescência , Espectrometria de Fluorescência , Espectrofotometria Infravermelho , Espectrofotometria UltravioletaRESUMO
The synthesis and characterization of two new zinc(II) coordination compounds with 3- and 4-aminopyridine are reported. They were obtained after adding a water solution of Zn(CH3COO)2·2H2O or dissolving solid Zn(CH3COO)2 â 2H2O in methanol solutions of 3- and 4-aminopyridine. The products were characterized structurally by single-crystal X-ray diffraction analysis. Colourless crystals of the compound synthesized by the reaction of Zn(CH3COO)2·2H2O and 3-aminopyridine (3-apy), are built of trinuclear complex molecules with the formula [Zn3(O2CCH3)6(3-apy)2(H2O)2] (1). The molecules consists of two terminal Zn atoms, coordinated tetrahedrally, and one central Zn atom, coordinated octahedrally. Colourless crystals, obtained by the reaction of Zn(CH3COO)2·2H2O with 4-aminopyridine (4-apy), consist of a mononuclear complex [Zn(O2CCH3)2(4-apy)2] (2). Hydrogenâbonding interactions in the crystal structures of both complexes are reported.
Assuntos
Acetatos/síntese química , Aminopiridinas/síntese química , 4-Aminopiridina , Acetatos/química , Aminopiridinas/química , Cristalografia por Raios X , Ligação de Hidrogênio , Acetato de ZincoRESUMO
2-Picolyl azide reacts with cis-[PtCl2(DMSO)2] to form the diimino complex [Pt(II)Cl2{NHâC(H)Py}] with subsequent dinitrogen liberation. The formation of the latter complex is scrutinized in a combined experimental and theoretical analysis. We establish in silico that the transformation involves a highly reactive intermediate containing a PtâN double bond formed after the extrusion of N2 from the azide functionality. The prerequisites for N2 liberation and for the stabilization of the nitrene-related intermediate are analyzed in detail.
RESUMO
In the title compound, C(16)H(13)NO(2), the quinoline system is approximately planar with a maximum deviation from the least-squares plane of 0.059â (1)â Å for the N atom. The phenyl ring is rotated by 62.16â (4)° with respect to the plane of the quinoline system. In the crystal, O-Hâ¯O hydrogen bonds link mol-ecules into infinite chains running along the b-axis direction.
RESUMO
The complexes [(C5Me4R)TiF(µ-F)µ-O2P(OSiMe3)2]2 [R = Me (1), Et (2)] were prepared from [(C5Me4R)TiF3]2, (R = Me, Et) and OP(OSiMe3)3. The molecular structure of 2 has been determined by single-crystal X-ray diffraction analysis. An eight-membered Ti2O4P2 metallacycle bridged by two fluorine ligands between two titanium centers is observed.
RESUMO
In the title compound, C(12)H(13)NO(3), the quinoline ring system is approximately planar with a maximum deviation from the least-squares plane of 0.058â (2)â Å. In the crystal, N-Hâ¯O and O-Hâ¯O hydrogen bonds link the mol-ecules into chains running along the b-axis direction. The chains also feature π-π inter-actions between pyridine and benzene rings of inversion-related mol-ecules [centroid-centroid distance = 3.609â (2)â Å].
RESUMO
In the title hydrate, C(12)H(13)NO(4)·H(2)O, the piperidine ring that is fused to the benzene ring is in a sofa conformation with the chiral C atom lying 0.4084â (18)â Å out of the plane of the nine fused-ring atoms. In the crystal, O-Hâ¯O and N-Hâ¯O hydrogen bonds link the organic mol-ecules and water mol-ecules into chains running along the b-axis direction. The chains are further connected into layers parallel to the bc plane by π-π inter-actions between inversion-related benzene rings [centroid-centroid distance = 3.8846â (9)â Å].
RESUMO
In the title compound, C(15)H(13)NO(2), the indole and benzene rings make a dihedral angle of 60.61â (4)°. In the crystal, dimeric pairs (twofold symmetry) are formed via O-Hâ¯O hydrogen bonds.
RESUMO
In this paper, Cu(II), Mn(II) and Zn(II) complexes with N,N,N-trimethyl-2-oxo-2-(2-(1-(thiazol-2-yl)ethylidene)hydrazinyl)ethan-1-aminium chloride (HL1Cl) were synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and DFT calculations. In all three complexes, a ligand (L1) is coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Cu(II) and Zn(II) form mononuclear penta-coordinated complexes [CuL1(N3)(CH3OH)]BF4 and [ZnL1(N3)2], respectively, while Mn(II) forms a binuclear [Mn2L12(µ-1,1-N3)2(N3)2]·2CH3OH complex, with unusual distorted trigonal-prismatic geometry around the metal centers. The antimicrobial activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two yeasts and one fungal strain. The binuclear Mn(II) complex showed antifungal activity of similar intensity to amphotericin B. Based on the results of the brine shrimp test and DPPH radical scavenging activity, the most active Cu(II) and Mn(II) complexes were selected for evaluation of cytotoxic activity against five malignant cancer cell lines (HeLa, A375, MCF7, PC-3 and A549) and one normal cell line HaCaT. Both complexes showed significant activity. It should be pointed out that the activity of the Mn(II) complex against the MCF7 breast cancer cell line is only slightly weaker than that of cisplatin, but with selectivity to the tumor cell line in comparison to normal HaCaT cells, which is non-existent in the case of cisplatin.
Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Complexos de Coordenação/farmacologia , Teoria da Densidade Funcional , Animais , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Antioxidantes/síntese química , Antioxidantes/química , Artemia/efeitos dos fármacos , Compostos de Bifenilo/antagonistas & inibidores , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cobre/química , Cobre/farmacologia , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Fungos/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Hidrazonas/química , Hidrazonas/farmacologia , Manganês/química , Manganês/farmacologia , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Picratos/antagonistas & inibidores , Compostos de Amônio Quaternário/química , Compostos de Amônio Quaternário/farmacologia , Zinco/química , Zinco/farmacologiaRESUMO
We report that 1-(2-picolyl)-1,2,3-triazole (click triazole) forms stable complexes with transition-metal ions in which the coordination involves the triazole N2 nitrogen atom and the pendant 2-picolyl group. This is exemplified by model compound 1-(2-picolyl)-4-phenyl-1H-1,2,3-triazole (L(x)) and its complexes with transition-metal ions of Pt(II), Pd(II), Cu(II), Ru(II), and Ag(I). The coordination was investigated experimentally and theoretically. Ligand L(x) easily reacted at room temperature with cis-[PtCl(2)(DMSO)(2)], [Pd(CH(3)CN)(4)](BF(4))(2), CuCl(2), [RuCl(mu-Cl)(eta(6)-p-cymene)](2), and AgNO(3) to give stable chelates [PtCl(2)L(x)] (1), [Pd(L(x))(2)](BF(4))(2) (2), [CuCl(2)(L(x))(2)] (3), [RuCl(eta(6)-p-cymene)L(x)]OTf (4), and [Ag(2)(L(x))(2)(NO(3))(2)] (5), respectively, in 60-98% yield. The structures of 1-5 were unambiguously confirmed by NMR spectroscopy and single-crystal X-ray diffraction analysis. Density functional theory calculations were carried out in order to theoretically investigate the stabilization factors in 1-5. A comparison of the chelating properties of ligand L(x) was made with structurally similar and isomeric 1-(2-aminoethyl)-substituted 1,2,3-triazole (L(y)) and 4-(2-aminoethyl)-substituted 1,2,3-triazole (L(z)). The complexation affinity of L(x) was attributed to pi-back-donation from the metal to the pendant pyridine side arm, whereas the stability of the complexes involving L(y) and L(z) mainly originates from efficient pi-back-donation to the triazole ring.
Assuntos
Compostos Organometálicos/síntese química , Piridinas/química , Elementos de Transição/química , Triazóis/química , Simulação por Computador , Cristalografia por Raios X , Íons/química , Ligantes , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/químicaRESUMO
The reaction of N-(2-pyridyl)thiourea with CuCl2 in methanol yields four different crystalline products: yellow dimeric complex, [Cu2Cl2(?-Cl)2(L)2] (1), red polymeric complex, [Cu3Cl8L2]n (2), orange crystalline product with ionic structure, L2[CuCl4] (3), and colourless ionic compound LCl (4), where L = 2-amino-[1,2,4]thiadiazolo[2,3-a]pyridin-4-ium cation as a result of oxidative cyclization of N-(2-pyridyl)thiourea. The crystal structures of all these crystalline products have been determined by single-crystal X-ray diffraction analysis. Compound 1 involves a copper(I) ion while in 2 and 3 the copper centre is in the divalent state. 1H NMR spectra for compounds 1-3 are identical and confirm deprotonated thioamide groups of N-(2-pyridyl)thiourea and the formation of a thiadiazolopyridinium cation in solution. The hydrogen bonding and ?-? stacking interactions were investigated in the solid state. In addition, all crystalline products 1-4 exhibit also S···Cl bonding interactions which consolidate the complexes into networks. The X-ray diffraction analyses indicate the absence of other crystalline phases in the crude reaction mixture.
RESUMO
(1-(2,4-Dioxo-1,2,3,4-tetrahydroquinolin-3-yl)-1H-1,2,3-triazol-4-yl)methyl acetates substituted on nitrogen atom of quinolinedione moiety with propargyl group or (1-substituted 1H-1,2,3-triazol-4-yl)methyl group, which are available from the appropriate 3-(4-hydroxymethyl-1H-1,2,3-triazol-1-yl)quinoline-2,4(1H,3H)-diones unsubstituted on quinolone nitrogen atom by the previously described procedures, were deacetylated by acidic ethanolysis. Thus obtained primary alcohols, as well as those aforenamed unsubstituted on quinolone nitrogen atom, were oxidized to aldehydes on the one hand with pyridinium chlorochromate (PCC), on the other hand with manganese dioxide, and to carboxylic acids using Jones reagent in acetone. The structures of all prepared compounds were confirmed by 1H, 13C and 15N NMR spectroscopy. The corresponding resonances were assigned on the basis of the standard 1D and gradient selected 2D NMR experiments (1H-1H gs-COSY, 1H-13C gs-HSQC, 1H-13C gs-HMBC) with 1H-15N gs-HMBC as a practical tool to determine 15N NMR chemical shifts at the natural abundance level of 15N isotope.
RESUMO
A copper(II) complex with the pyridoxal-aminoguanidine (PL-AG) Schiff base adduct, as an organic compound of the very potent biological activity and promising pharmacological importance in the treatment of diabetic complications, has been prepared and characterized. The X-ray structural analysis of the [CuCl2(PL-AG)] complex showed that it has a distorted pseudo-square-pyramidal (4+1) structure with the tridentate ONN Schiff base in the equatorial plane, with the Cu-O(1), Cu-N(1) and Cu-N(3) bond lengths of 1.917(2)A, 1.930(2)A and 1.984(2)A, respectively. The bond length of the equatorial Cu-Cl(1) is 2.279(1)A, while that of the apical Cu-Cl(2) is 2.792(1)A. Pyridoxal fragment is coordinated in its zwitterionic form. In addition to the X-ray structural analysis, the complex was characterized by IR spectrometric, conductometric and magnetic techniques, and the ligand itself by IR, 1H and 13C NMR spectra.
Assuntos
Cobre/química , Guanidinas/química , Espectroscopia de Ressonância Magnética/métodos , Piridoxal/química , Bases de Schiff/química , Cristalografia por Raios X/métodos , Ligantes , Modelos Moleculares , Estrutura MolecularRESUMO
In this work synthesis, characterization and crystal structures of two isothiocyanato Fe(III) complexes with 2,2'-[2,6-pyridinediylbis(ethylidyne-1-hydrazinyl-2-ylidene)]bis[N,N,N-trimethyl-2-oxoethanaminium] dichloride (H2LCl2) ligand, with composition [FeL(NCS)2]SCN·2H2O and [FeL(NCS)2]2[Fe(H2O)(NCS)5]·4H2O, has been reported. Both iron(III) complexes possess the same pentagonal-bipyramidal complex cation, while the nature of their anions depends on mole ratio of NH4SCN and FeCl3·6H2O used in reaction. Cytotoxic activity of new Fe(III) complexes, as well as of previously synthesized isothiocyanato Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) complexes with the same ligand, was tested against five human cancer cell lines (HeLa, MDA-MB-453, K562, LS174 and A549) and normal cell line MRC-5. The best activity was observed in the case of Fe(III), Co(II) and Cd(II) complexes. The investigation of potential of these complexes to induce HeLa and K562 cell cycle perturbations was also evaluated. Mechanism of cell death mode was elucidated on the basis of morphological changes of HeLa cells as well as identification of target caspases. It was established that DNA damage could be responsible for the activity of Fe(III) and Co(II) complexes. SYNOPSIS: Pentagonal-bipyramidal Fe(III) complexes with dihydrazone of 2,6-diacetylpyridine and Girard's T reagent have been synthesized and characterized. Cytotoxic activity of Fe(III) complexes and Co(II), Ni(II), Mn(II), Zn(II) and Cd(II) complexes with the same ligand was tested. The best activity was observed in the case of Fe(III), Co(II) and Cd(II) complexes.
Assuntos
Antineoplásicos , Betaína/análogos & derivados , Ciclo Celular/efeitos dos fármacos , Compostos Férricos , Hidrazonas , Piridinas , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Betaína/química , Betaína/farmacologia , Morte Celular/efeitos dos fármacos , Dano ao DNA , Compostos Férricos/síntese química , Compostos Férricos/química , Compostos Férricos/farmacologia , Células HeLa , Humanos , Hidrazonas/química , Hidrazonas/farmacologia , Células K562 , Piridinas/química , Piridinas/farmacologiaRESUMO
A novel bis(pyridyl-functionalized 1,2,3-triazol-5-ylidene)-palladium(II) complex [Pd(Py-tzNHC)2](2+) catalyses the copper-, amine-, phosphine-, and additive-free aerobic Sonogashira alkynylation of (hetero)aryl bromides in water as the only reaction solvent. The catalysis proceeds along two connected Pd-cycles with homogeneous bis-carbene Pd(0) and Pd(II) species, as demonstrated by electrospray ionization mass spectrometry.
RESUMO
Metal complexes with ML or ML2 stoichiometry have been isolated in the reaction of Zn(NO3)2, ZnBr2 or M(NO3)2/NaBF4, M = Zn(ii), Co(ii) or Ni(ii), with either amino acid or amine substituted tridentate nitrogen ligands based on bis(2-picolyl)amine (bpa) or bis(2-quinaldyl)amine (bqa). The stoichiometry (M : L = 1 : 1 or 1 : 2) and stereochemistry (mer, trans-fac or cis-fac) of the products have been studied by NMR and IR spectroscopy, X-ray single crystal analysis and quantum-chemical calculations with an implicit SMD solvation model.
Assuntos
Aminas/química , Aminoácidos/química , Cobalto/química , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Níquel/química , Ácidos Picolínicos/química , Zinco/química , Cristalografia por Raios X , Ligantes , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrometria de Massas por Ionização por Electrospray , EstereoisomerismoRESUMO
The synthesis and spectroscopic characterization of some pyrimidinium hexafluoridosilicate salts with the formula (RH)2[SiF]6 (where R = 2-aminopyrimidine (1), cytosine (2) and 5-cyanocytosine (3)) is obtained in the reaction of SiO2 with hydrofluoric acid solution and subsequent addition of 2-aminopyrimidine, cytosine or 4-amino-2-chloropyrimidine-5-carbonitrile. The crystal structures of 1 and 3 have been determined by single-crystal Xâray diffraction analysis. The combination of NâH···F hydrogen bonds along with πâπ interactions between aromatic rings resulted in supramolecular architecture of cations and anions in the solid state.
RESUMO
A general protocol to independently access stereoisomerically pure ß'-hydroxy-ß-amino acid derivatives that is based on dibutylboron triflate-mediated aldol reaction of suitably protected ß-amino acids bearing chiral oxazolidinone auxiliary is reported. The method smoothly afforded syn-aldol (α,ß'-syn) products in pure form and excellent isolated yield. Both α,ß-syn and α,ß-anti isomers are readily accessible solely through the choice of the oxazolidinone chirality. This method allows for the preparation of stereoisomeric ß'-hydroxy-ß-amino acid derivatives that were previously unreported.