The fragmentation of 1-phenyl-, l-(2′-pyridyl)- and 1-(4′-methyl-2′-quinolyl)-4-acetoacetyI-3-methyIpyrazol-5-ols (compounds 1, 2 and 3, respectively) on electron impact has been studied and the major processes interpreted. The common feature in the mass spectra of these compounds is the loss of ketene, acetonyl radical, acetone and two molecules of ketene from the molecular ion. Whereas the ion generated after the last process, which corresponds to 1-substituted-3-methyIpyrazol-5-ols, loses methyl cyanide in the case of 1, similar ions in the case of 2 and 3 lose ?2HO moiety, necessitating an intramolecular hydrogen transfer followed by ring fission and subsequent loss of methyl cyanide. All these and other related processes have been substantiated with the help of accurate mass measurements of the fragment ions and B/E linked-scan spectra. 相似文献
Treatment of M(OiPr)4 (M = Ti, V) and [Zr(OEt)4]4 with excess 1,4-HOC6H4OH in THF afforded [M(OC6H4O)a(OC6H4OH)3.34-1.83a(OiPr)0.66-0.17a(THF)0.2]n (M = Ti, 1-Ti; V, 1-V, 0.91 < or = a < or = 1.82) and [Zr(1,4-OC6H4O)2-x(OEt)2x]n (1-Zr, x = 0.9). The combination of of 1-M (M = Ti, V, Zr) or M(OiPr)4 (M = Ti, V), excess 1,4- or 1,3-HOC6H4OH, and pyridine or 4-phenylpyridine at 100 degrees C for 1 d to 2 weeks afforded various 2-dimensional covalent metal-organic networks: [cis-M(mu 1,4-OC6H4O)2py2] infinity (2-M, M = Ti, Zr), [trans-M(mu 1,4-OC6H4O)2py2.py] infinity (3-M, M = Ti, V), solid solutions [trans-TixV1-x(mu 1,4-OC6H4O)2py2.py] infinity (3-TixV1-x, x approximately 0.4, 0.6, 0.9), [trans-M(mu 1,4-OC6H4O)2(4-Ph-py)2] infinity (4-M, M = Ti, V), [trans-Ti(mu 1,3-OC6H4O)2py2] infinity (5-Ti), and [trans-Ti(mu 1,3-OC6H4O)2(4-Ph-py)2] infinity (6-Ti). Single-crystal X-ray diffraction experiments confirmed the pleated sheet structure of 2-Ti, the flat sheet structure of 3-Ti, and the rippled sheet structures of 4-Ti, 5-Ti, and 6-Ti. Through protolytic quenching studies and by correspondence of powder XRD patterns with known titanium species, the remaining complexes were structurally assigned. With py or 4-Ph-py present, aggregation of titanium centers is disrupted, relegating the building block to the cis- or trans-(ArO)4Tipy2 core. The sheet structure types are determined by the size of the metal and the interpenetration of the layers, which occurs primarily through the pyridine residues and inhibits intercalation chemistry. 相似文献
Lysozyme is widely used for the synthesis of nanomaterials (e.g., gold nanoparticle) to fluorescently sense metal ions. However, the effect of metal ions on the fluorescence of lysozyme is not studied yet. Herein, we have explored the interactions of lysozyme with different metal ions to develop a direct sensing platform for Fe(III). It has been observed that the fluorescence of lysozyme was slightly decreased in the presence of Cu(II), Hg(II), As(V), Co(II), Cd(II), Cr(II), Fe(II), Mn(II), Pb(II), and Zn(II), while a significant decrease in the lysozyme fluorescence was observed for Fe(III). The effect of thermal stability on the fluorescence quenching was also studied from 25 to 60 °C. In the present study, the lysozyme sensing probe was able to selectively and accurately detect 0.5–50 ppm of Fe(III) with a LOD of 0.1 ppm (1.8 µM) at 25 °C.
Surgery, chemotherapy and radiotherapy, the conventional treatment modalities of cancer though successful are limited by presence of residual tumor cells, toxic side-effects and treatment resistance, thus raising the need for investigating other novel approaches. Here, we have used a cold atmospheric plasma (CAP) jet and assessed the in vitro efficacy in gingivobuccal squamous cell carcinoma (GB-SCC) – ITOC-03, breast adenocarcinoma—MCF7 and HEK293 cells. Cells lines were subjected to varying doses of ionizing radiation (0, 2, 4, 6, 8 Gy) and CAP jet treatment (0, 60, 180, 240, 300 s). CAP jet treatment showed time dependent increase in H2O2 and NO2? concentration. Cell viability assay showed potent effect of CAP jet on all three cell lines in comparison to radiation treatment, while helium gas treatment showed minimal inhibitory effect. Irradiated, CAP jet and helium gas treated cells showed loss of nucleic acid features, 788 cm?1 and 1340 cm?1 in Raman spectra, indicating DNA damage. Principal Component Analysis (PCA) showed distinct classification of CAP-treated and control cells, while Principal Component – Linear Discriminant Analysis (PC-LDA) based classification of Raman spectra showed ITOC-03 and HEK293 cells to be sensitive to CAP jet and radiation treatment in comparison to MCF7 cells. Collectively, cell viability assay and Raman spectroscopy have shown potent effect of CAP jet in GB-SCC and breast adenocarcinoma cells.
Summary Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes of 4-amino-5-mercapto-3-trifluoromethyl-s-triazole (AMTT) and 5-mercapto-4-salicylideneamino-3-trifluoromethyl-s-triazole (MSTT) have been synthesized and characterized on the basis of elemental analyses, magnetic measurements, infrared and electronic spectral data. The ligandsAMTT andMSTT were characterized by elemental analyses, infrared and1H NMR spectral studies.AMTT, involving N and S as donor atoms, andMSTT, involving N, O and S as donor atoms, act as bi- and tridentate ligands, respectively. The geometry of the complexes has been assigned on the basis of magnetic and electronic spectral data. EPR parameters for copper (II) complexes have been calculated. Thermal stabilities of the complexes are also reported. Due to insolubility in water and common organic solvents and infusibility at higher temperatures, all the complexes are thought to be polymeric in nature.
Triazole als Komplexierungs-Agentien: Synthese und Strukturuntersuchungen an einigen bivalenten Metallionenkomplexen mit zwei- und dreizähnigen Liganden
Zusammenfassung Es wurden Co(II)-, Ni(II)-, Cu(II)-, Zn(II)- und Cd(II)-Komplexe von 4-Amino-5-mercapto-3-trifluormethyl-s-triazol (AMTT) und 5-Mercapto-4-salizylidenamino-3-trifluormethyl-s-triazol (MSTT) hergestellt und mittels Elementaranalyse, magnetischen Messungen, Infrarot- und Elektronenspektroskopie charakterisiert. Die LigandenAMTT undMSTT wurden elementaranalytisch und spektroskopisch (IR und1H-NMR) charakterisiert.AMT wirkt über die N-und S-Donoratome als zweizähniger Ligand,MSTT über N, O und S als dreizähniger Ligand. Die Geometrie der Komplexe wurde auf der Basis von magnetischen und elektronenspektroskopischen Daten zugeordnet. Für die Cu(II)-Komplexe wurden die EPR-Parameter berechnet. Die thermischen Stabilitäten der Komplexe wurde ebenfalls untersucht. Wegen ihrer Unlöslichkeit in Wasser und gängigen organischen Lösungsmitteln und der Unschmelzbarkeit bei höheren Temperaturen wird eine polymere Natur der Komplexe angenommen.
The photodegradation reactions of riboflavin (RF) in the presence of 0.05-2.00 M phosphate (pH 7.0) have been studied using a specific multicomponent spectrophotometric method. The reactions involve simultaneous photolysis (intramolecular photoreduction) and photoaddition (intramolecular photoaddition) leading to lumichrome (LC) and cyclodehydroriboflavin (CDRF), respectively, as major products. The contribution of each reaction in the overall photodegradation depends upon the phosphate concentration, i.e., higher the phosphate concentration higher the extent of photoaddition. The apparent first-order rate constants for the photodegradation of RF and for the formation of LC and CDRF at 0.25-2.00 M phosphate concentration range from 0.65 to 3.03 x 10(-2), and from 0.41 to 0.99 x 10(-2) and 0.12 to 1.63 x 10(-2) min(-1), respectively. The second-order rate constants for the phosphate catalysed photodegradation of RF and for the formation of LC and CDRF are 2.12 x 10(-4) and 0.61 x 10(-4) and 1.41 x 10(-4) M(-1)s (-1), respectively. Since the formation of CDRF by photoaddition is catalysed by HPO(4)(2-) ions, it is suggested that H(2)PO(4)(-) ions may be involved in the formation of LC by photolysis. Thus, both H(2)PO(4)(-) and HPO(4)(2-) ions may catalyse the two major reaction pathways of riboflavin photodegradation, respectively. 相似文献
To investigate the molecular interaction study between secondary amine with aryl and alkyl ether, we report densities, speeds of sound, viscosities and refractive indices of N-ethylaniline (NEA) with aryl (anisole, phenetole) and alkyl (tert-butyl methyl ether) ether over the entire composition regime and in the temperature range of 293.15–323.15 K at 5 K intervals. Various excess and transport properties were derived from the experimental data and the excess parameters were fitted to the Redlich–Kister polynomial equation using multiparametric non-linear regression analysis to derive the binary coefficients and to estimate the standard deviation. Molecular interactions between the unlike molecules were analysed through dipole–dipole interactions, cross-association between the components of the mixtures and H-bond formation. Viscosity and refractive index of the mixtures were predicted through several empirical equations and compared with the experimental results. Prigogine–Flory–Patterson statistical theory was used to predict the excess molar volume results. 相似文献