Search results for "UV–vis"
showing 8 items of 18 documents
Interactions of zinc octacarboxyphthalocyanine with selected amino acids and with albumin
2015
Effect of selected amino acids (glycine, l-histidine, l-cysteine, l-serine, l-tryptophan) and albumin on the spectroscopic properties and photostability of zinc octacarboxyphthalocyanine (ZnPcOC) was explored in the phosphate buffer at a pH of 7.0. The photodegradation of ZnPcOC alone and in the presence of amino acids or albumin has been investigated in aqueous phase using UV-366 nm and daylight irradiation. Kinetic analysis showed that the interaction with amino acids or albumin enhances the photostability of ZnPcOC. To answer the question of how zinc phthalocyanine interacts with amino acids extensive DFT calculations were performed. Analysis of the optimized geometry features of ZnPcOC:…
A novel pro-apoptotic role of zinc octacarboxyphthalocyanine in melanoma me45 cancer cell's photodynamic therapy (PDT)
2018
Abstract Zn-based phthalocyanine acts as drug or photosensitizer in photodynamic therapy (PDT) for the treatment of cancer cells. The activated zinc octacarboxyphthalocyanine (ZnPcOC) reacts with oxygen, to generate reactive oxygen species for the damage of melanoma cancer cells, Me45. This in vitro study aimed at investigating the cytotoxic effects of different concentrations of ZnPcOC activated with a diode laser (λ = 685 nm) on Me45, and normal human fibroblast cells, NHDF. To perform this study 104 cells/ml were seeded in 96-well plates and allowed to attach overnight, after which cells were treated with different concentrations of ZnPcOC (10, 20 and 30 μM). After 4 h, cells were irradi…
Investigation of phthalocyanine crystals exposed to NO2 ambient gas
2002
Crystals of free base phthalocyanine (H2pc) and its unsubstituted metal derivatives Mpc (where M=Ni, Cu, Zn, Pb, and pc=C32H16N8 2−=phthalocyanine ligand) were examined after being exposed to NO2 ambient gas. Scanning electron microscopy (SEM) supported by X-ray microprobe analysis (EDAX), UV–Vis and FTIR spectroscopy as well as X-ray powder diffractometry (XRD) were applied to study the crystals chemistry and surface morphology. The NO2 molecules were found to penetrate the crystal unit which led to the breakdown of the phthalocyanine macrocycle. The surface of the doped crystals has been scaled and covered by a layer composed predominantly of phthalimide. Despite vacuum desorption, it has…
Sulfur Dioxide Oxidation Catalyzed by Photosensitized Ytterbium Diphthalocyanine
2008
Oxidation of SO2 into SO3 was found effectively catalyzed by photosensitized ytterbium diphthalocyanine, YbPc2 (Pc = phthalocyanine ligand, C32H16N8) when performed in air-saturated dimethylformamide (DMF) solution at 20 °C. The process follows according to a multi-step complex mechanism involving chemical induction as its driving force. Excitation energy of the sandwich molecular system in YbPc2 is used to promote the reaction by creating a reactive intermediate form of the ytterbium complex hosting up to eight SO2 molecules. The conversion of SO2 proved complete.
Complexation of phosphine ligands with peracetylated β-cyclodextrin in supercritical carbon dioxide: Effect of temperature and cosolvent on the equil…
2009
Abstract The interaction between peracetylated-β-cyclodextrin and tert-butyl and adamantyl functionalized triphenylphosphine derivatives was studied in supercritical carbon dioxide (scCO 2 ) based solvent media by UV–vis spectroscopy. The equilibrium constant for a 1:1 complexation reaction was obtained from titration spectra both in pure carbon dioxide and in the presence of methanol as a cosolvent in the temperature range 308–323 K to estimate the internal energy and entropy of the inclusion equilibrium. The values of the equilibrium constants were found significantly smaller than those obtained in aqueous solution with analogous phosphines and substantially independent of the nature of t…
Equilibria involved in the diorganotin(IV) and triorganotin(IV) phosphomycin interaction in aqueous solution
2007
Four new diorganotin(IV), (R = Me, Bu), and triorganotin(IV), (R = Me, Ph), derivatives of the phosphomycin disodium salt antibiotic[(1R,2S)-1,2-epoxypropylphosphonate]Na2 have been synthesized and their solid state configuration studied by X-ray crystallography, FT-IR, Mossbauer, UV–Vis spectroscopies. The X-ray diffraction investigation, performed on the bis[trimethyltin(IV)]- phosphomycin, showed that the coordination geometry at all the Sn atoms is trigonal bipyramidal. The structure of the complex forms an unusual polymeric zig-zag planar network. The FT-IR and the 119Sn Mo¨ssbauer studies supported the formation of trigonal bipyramidal (Tbp) molecular structures, both in the diorganot…
Crystal structure, Hirshfeld surface analysis and DFT studies of (E)-1-(4-bromophenyl)-3-(3-fluorophenyl)prop-2-en-1-one
2018
The title halogenated organic chalcone was prepared by a Claisen–Schmidt condensation reaction. A Hirshfeld surface analysis was carried out to reveal the percentage contributions of the intermolecular interactions. A theoretical study was performed using the density functional theory (DFT) at B3LYP with the 6–311 G++(d,p) basis set level to compare with the experimental results of the X-ray analysis and UV–vis absorption analysis in term of the geometrical parameters, HOMO-LUMO energy gap and charge distributions.
Examples of UV–Vis profiles use as tool for evidence of the metallophthalocyanines transformation
2017
Abstract The UV–Vis spectra for a set of MPcs (Mmetal, Pc = phthalocyanine ligand), i.e.: In(III)PcI (1), Hf(IV)PcI2Pht (Pht = phthalonitrile) (2), Sn(II)Pc (3), Sn(IV)PcI2 (4), and Ge(IV)PcI2 (5) have been examined in two solvents, O-donative acetylacetone, and non-coordinative benzene. The UV–Vis spectra in Hacac solution of 1,2 and 4,5 shows that the axially ligated iodine atoms are replaced by (acac)− anions of the solvent, whereas in 3 the oxygen donors of the solvent causing the auto-oxidation of Sn(II) to Sn(IV) ions and as a result the Sn(II)Pc is transformed into the Sn(IV)Pc(acac)2. The chloride complexes of the 1–5 compounds are formed at Hacac solution after acidification by hyd…