SPECTROSCOPICALLY AND/OR STRUCTURALLY INTRIGUING PHTHALOCYANINES AND RELATED COMPOUNDS. PART 2. MONOMERIC SYSTEMS

The second part of the series of review papers on the properties of some synthetically and spectroscopically interesting studies of our group for the period 2007-2017 is presented. In particular, examples of the analysis of spectroscopic data in combination with calculations by the molecular orbitals method are given. We mainly used spectroscopic methods of electron absorption and natural and magnetic circular dichroism, periodically applying fluorescence, phosphorescence and ESR with a time resolution. The spectra of (4n + 2) p systems, as well as some 4np antiaromatic systems, are analyzed theoretically, which helps the reader to interpret the spectral data. In the first and the second parts of this review monomer systems are considered, and in the third - trimeric and tetrameric systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . .. . .. . . .. .. .. . . . . . . . . . . . . . . .. . . . . . .. . . .. .. . .. . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. .. . . .. . . . . . . . .. .. . . . . . . .. . . . . . . .. . . .. . . . .. . . .. . . . . . .. . . .. .. . . . . . .. . . . .. . .. .. . .

Mechanisms and Parameters of the Binding of Amitozinoberamid to DNA in the Aqueous Solution

The interaction between the amitozinoberamid preparation (thiotepa-alkylated berberine) and a DNA macromolecule in the aqueous solution has been studied, by using the optical spectroscopy methods: electron absorption and fluorescence. The dependence of spectral characteristics on the concentration ratio N/c between the DNA base pairs and the ligand molecules is plotted. Using the system of modified Scatchard and McGhee–von Hippel equations, the parameters of the binding of amitozinoberamid to DNA are determined. A comparative analysis of the DNA interaction with amitozinoberamid, on the one hand, and berberine and sanguinarine alkaloids, on the other hand, is carried out. The structure and the spectra of electron absorption of thiotepa, berberine, and amitozinoberamid molecules are calculated in the framework of the density functional theory at the DFT B3LYP/6-31G(d,p) level.

SPECTROPHOTOMETRIC STUDY OF ACID-BASE PROPERTIES OF SPATIAL-DISTORTED DERIVATIVES OF PORPHYRINS IN ACETONITRILE

Spectrophotometric titration method was used to study the acidic properties of: 5,10,15,20-tetrakis(thienyl-2-yl)-2,3,7,8,12,13,17,18-octaethylporphyrin (I), 5,10,15,20-tetrakis(4’-t-butylphenyl)-2,3,7,8,12,13,17,18-octaethylporphyrin (II), 5,10,15,20-tetrakis(3,5-di-t-butylphe-nyl)-2,3,7,8,12,13,17,18-octaethylporphyrin (III), 5,10,15,20-tetraphenyl-2,3,7,8,12,13,17,18-octaethylporphyrin (IV), 5,15-bis(4’-methoxyphenyl)-10,20-bis(4-nitro-phenyl)-2,8,12,18-tetrame-thyl-3,7,13,17-tetraarylporphyrin (V), 5,15-bis(4’-methoxyphenyl)-10,20-diphenyl-2,3,7,8,12,13, 17,18-octaethylporphyrin (VI), 5,15-bis(4’-methoxyphenyl)-2,8,12,18-tetramethyl-3,7,10,13,17,20-hexaethylporphin (VII), 5,10,15,20-tetrakis(4’-methoxyphenyl)-2,3,7,8,12,13,17,18-octaethylpor-phyrin (VIII) in the presence of a deprotonated agent, 1,8-diazabicyclo[5.4.0] undec-7-ene, in acetonitrile. Under deprotonation two families of spectral curves in the absorption spectra, having its own system of isobestic points, are formed. Electron absorption spectrum of molecular form transforms gradually into the spectrum of the final form of dianion with titrant concentration increase. Determination of the coordinates of the inflection (and the corresponding concentration of DBU) on the titration curve allowed us to distinguish two areas in the electron absorption spectra of the reaction system, which are likely belong to the first and second steps of deprotonation, namely, to the formation of mono- and dianionic forms (HP– and P2–) of the compound. Spectral characteristics of the ionized forms and combined ionization constant for the first and second steps (lgКа1 and lgКа2) were revealed. At the first step in the order of decreasing acidic properties of the ligands the compounds form a series of: III< V< VIII< VI < VII< II< IV < I; at the second step in decreasing order of the acidic properties of the ligands the compounds form a series of:.III < V < VI < II <VIII< VII < IV < I. The effect of structural and electronic properties of substituents on acid-base properties of porphyrins is analyzed. Thus, chemical modification of the macrocycle can lead to direct changes in acid-base properties of supramolecular macroheterocyclic ligands and can be a powerful tool to control the reactivity of compounds of the porphyrins class.

Synthesis of novel push-pull fluorescent dyes – 7-(diethylamino)furo[3,2-c]coumarin and 7-(diethylamino)thieno[3,2-c]coumarin derivatives

Novel push-pull fluorescent dyes, 7-(diethylamino)furo[3,2-c]coumarin and 7-(diethylamino)thieno[3,2-c]coumarin derivatives, were designed and synthesized using formyl derivatives of furo- and thieno[3,2-c]coumarins as key intermediates. Electron absorption and emission spectra of the dyes were recorded in different solvents. The longest-wave bands in the electron absorption spectra of the dyes are suggested to be of push-pull nature.

Spectroscopic studies of the quality of WCO (Waste Cooking Oil) fatty acid methyl esters

Different kinds of biodiesel fuels become more and more attractive form of fuel due to their unique characteristics such as: biodegradability, replenishability, and what is more a very low level of toxicity in terms of using them as a fuel. The test on the quality of diesel fuel is becoming a very important issue mainly due to the fact that its high quality may play an important role in the process of commercialization and admitting it on the market. The most popular techniques among the wellknown are: molecular spectroscopy and molecular chromatography (especially the spectroscopy of the electron absorption and primarily the infrared spectroscopy (FTIR)).The issue presents a part of the results obtained with the use of spectroscopy of the electron absorption and in majority infrared spectroscopy FTIR selected for testing samples of the acid fats WCO (Waste Cooking Oil) types. The samples were obtained using laboratory methods from sunflower oil and additionally from waste animal fats delivered from slaughterhouses. Acid methyl esters were selected as references to present the samples. In order to facilitate the spectroscopic analysis, free glycerol, methanol, esters and methyl linolenic acid were measured