Search results for "UV-vis spectra"
showing 5 items of 5 documents
Aggregation of Free-Base Octacarboxyphthalocyanine in Aqueous Solutions
1999
Results of spectral (UV-VIS) investigations on the aggregation phenomena of the freebase 2,3,9,10,16,17,23,24-octacarboxypthalocyanine are reported. Phthalocyanine exists mainly in associated (aggregated) froms in water. The aggregates are present even in very diluted (10-7 -10-6 mol/dm-3) solutions. The hydrogen bonding between the carboxyl groups of the adjacent molecules in considered. The increase in pH and temperature, as well as the presence of the cationic surfactant and alcohols (in an appropriate quantity) cause a prtial or full disaggregation. The spectrum of the monomeric phthalocyanine from has been observed. The increase in H2Pc(COOH)8 concentration, the decrease in pH, as well…
Hydrogen bond-mediated conjugates involving lanthanide diphthalocyanines and trifluoroacetic acid (Lnpc2@TFA): Structure, photoactivity, and stability
2020
The interaction between lanthanide diphthalocyanine complexes, LnPc2 (Ln = Nd, Sm, Eu, Gd, Yb, Lu
Copper Octacarboxyphthalocyanine Aggregation in Buffered Solutions
2008
Results of spectral UV-Vis absorption investigations on association of copper octa-carboxyphthalocyanine, CuPcOC, are reported. Influence of pH on association is discussed. In pH < 5.5 only ag gre gates are present. Monomer appears above pH = 5.5 and at pH Greater-than or equal to 6.2 only monomeric Pc forms exist. CuPcOC exhibits higher tendency to wards association in phosphate buffer solutions than in redistilled water. In pH 5.9–6.0 monomers, dimers and trimers coexist in equilibrium in 1.0×10–6 – 1.2×10–5 mol/dm3 concentration range at 25°C. The average assembling number n = 3 was determined for pH 5.6, 5.9 and 6.0 solutions. The spectrum of aggregate was calculated with two maxima at …
Synteza i właściwości fizykochemiczne ftalocyjaniny manganu
2017
Ftalocyjaniny to organiczne związki chemiczne, które uzyskuje się jedynie na drodze syntezy chemicznej. Stanowią one jednak analogi strukturalne porfiryn, które naturalnie występują w przyrodzie, m.in. w takich cząsteczkach jak witamina B12 czy chlorofil. Obszerne badania dotyczące kompleksów ftalocyjanin wynikają z budowy tych związków, ponieważ cząsteczkę ftalocyjaniny można modyfikować na bardzo wiele sposobów. Wpływa to na różnorodność zastosowań ftalocyjanin, m.in. w urządzeniach elektronicznych, fotowoltaicznych, jako fotosensiblilizatory, barwniki i pigmenty. Kompleksy ftalocyjanin z takimi metalami jak mangan czy kobalt są intensywnie badane ze względu na ich interesujące właściwośc…
Deconvolution procedure of the UV-vis spectra. A powerful tool for the estimation of the binding of a model drug to specific solubilisation loci of b…
2015
UV-vis-spectra evolution of Nile Red loaded into Tween 20 micelles with pH and [Tween 20] have been analysed in a non-conventional manner by exploiting the deconvolution method. The number of buried sub-bands has been found to depend on both pH and bio-surfactant concentration, whose positions have been associated to Nile Red confined in aqueous solution and in the three micellar solubilisation sites. For the first time, by using an extended classical two-pseudo-phases-model, the robust treatment of the spectrophotometric data allows the estimation of Nile Red binding constant to the available loci. Hosting capability towards Nile Red is exalted by the pH enhancement. Comparison between bin…