ir spectroscopy
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Solvent extraction is a method for purifying oil extracts, which are used as oil-plasticisers for industrial rubber goods, from cancerogenic hydrocarbons. The efficiency of this method is mainly determined by the selectivity and solvent properties of a separating agent. However, when carrying out a comparative analysis of promising extraction methods, it is necessary to use real-time methods for studying the composition of the resulting products. The purification efficiency of oil extracts from polycyclic aromatic components, including carcinogenic hydrocarbons (benzo[a]pyrene, benzo[e]pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene, etc.), was evaluated depending upon the nature of selective solvents. The structure-group composition of the purified oil extracts and those at the second-stage of purification was determined by FTIR spectroscopy. It was found that the extraction efficiency of the studied solvents towards polycyclic aromatic hydrocarbons from oil extracts increases in the following order: dimethyl sulfoxide < N-methylpyrrolidone + 10 wt% ethylene glycol <N-methylpyrrolidone +50 wt% triethylene glycol. When using a solvent comprising N-methylpyrrolidone + 50 wt% triethylene glycol, the proportion of polyalkyl-substituted and condensed aromatic structures in the purified oil extract decreases by 16.8%; the oil extract yield increases by over 25 wt% in contrast to extraction with N-methylpyrrolidone + ethylene glycol mixture, which meets the requirements of the European Union for oil extract purification (Directive No. 2005/69/EC). Therefore, we recommend the solvent comprising N-methylpyrrolidone + 50 wt% triethylene glycol for purifying oil extracts from components having a technogenic impact on the environment and human health and IR spectroscopy for efficiency assessment of solvent extraction of oil extracts.

Oligopyridine based copper(II) complexes are of interest to scientists as possible anticancer agents due to promising cytotoxic and DNA binding/cleaving properties. In this study, copper(II) complex [Cu(phendione)L2]·C2H5OH with 1,10-phenanthroline-5,6-dione (phendione) and 4,5-dichloro-isothiazole-3-carboxylic acid (HL) was synthesized and characterized by elemental analysis, IR-spectroscopy, X-ray powder diffraction and single-crystal X-ray diffraction. According to X-ray diffraction data, obtained compound is mononuclear complex with square pyramidal coordination environment of the central atom which is surrounded by two isothiazolate molecules and one phendione ligand. The X-ray diffraction data are confirmed by IR-spectroscopy data showing the presence of characteristic stretching vibration bands of the carbonyl and carboxyl groups of oligopyridine ligand and isothiazolate ions, respectively. Density functional theory (DFT) calculations for complex were carried out using the ADF software package to perform geometry optimization and frequency calculations that were in a good agreement with experimental IR spectrum. Cytotoxicity of complex and initial reagents was tested in vitro against HepG2 (human hepatocellular carcinoma) and MCF-7 (human breast adenocarcinoma) cell lines. The complex showed high dose-dependent cytotoxic activity with the IC50 values of 0.60±0.03 µM and 0.96±0.13 µM, respectively, which is higher than the activity of cisplatin against these cell lines. The activity of the complex is due to the presence of phendione ligand, which exhibits a similar cytotoxic activity.

The work is devoted to the synthesis and characterization of gels based on the monomers pentaerythritol triaacrylate (PETriA) and 2,2 '-(ethylenedioxy)diethanethiol (EDODET) by thiol-ene "click" polymerization. The properties of the obtained gels were investigated by IR, Raman spectroscopy, mechanical analysis. Sol-gel analysis of obtained networks was carried out and the degradability was investigated. The results of IR spectroscopy confirmed the presence of -C = O and -C-O-C- groups in the composition of the obtained gels. The presence of unreacted C = C bonds conjugated with C = O, as well as thiol groups, varies depending on the composition of the initial monomer mixture (IMM). Raman spectroscopy results correlate well with IR data. Raman spectra also show C-S, S-S and SH characteristic bands that are difficult to identify by IR spectroscopy. It was found that the composition of MM affects the physicochemical properties of the synthesized gels. The highest yield of the gel fraction of obtained polymers was found in samples with an equimolar composition of IMM. The analysis of mechanical properties showed that gels with an excess of PETriA exhibit more elastic properties, and an excess of EDODET leads to the formation of networks with a higher crosslinking density. The study of the ability of obtained PETria-EDODET gels to degrade in a 3% solution of hydrogen peroxide showed that the polymer network degrades by 12% within 60 days. This property of the obtained gels can find application in the creation of targeted drug delivery systems with their prolonged release.

The influence of irradiation with accelerated electrons (energy 8.5 MeV, dose 5 kGy) on the physical properties of medical devices made of polyethylene terephthalate (PET) by infrared (IR) spectroscopy was studied. The revealed post-radiation changes in the IR spectra can be used to justify the choice of the dose of irradiation of PET products with electrons during the radiation sterilization procedure.

Two new isostructural complexes, namely, poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)cobalt(II)], [Co(C15H8O7)(C12H8N2)(H2O)] n or [Co(μ3-Hcpota)(phen)(H2O)] n , I, and poly[aqua[μ3-2-(4-carboxyphenoxy)terephthalato-κ3 O 1:O 4:O 4′](1,10-phenanthroline-κ2 N,N′)nickel(II)], [Ni(C15H8O7)(C12H8N2)(H2O)] n or [Ni(μ3-Hcpota)(phen)(H2O)] n , II, have been synthesized by solvothermal reactions. Complexes I and II were fully characterized by IR spectroscopy, elemental analyses, thermogravimetric analyses, and powder and single-crystal X-ray diffraction. They both present two-dimensional structures based on [M 2(μ-COO)2]2+ (M = CoII or NiII) dinuclear metal units with a fes topology and a vertex symbol (4·82). Interestingly, the positions of the two dimeric metal motifs and the two partially deprotonated Hcpota2− ligands reproduce regular flying butterfly arrangements flipped upside down and sharing wings in the ab plane. Magnetic studies indicate antiferromagnetic interactions (J = −5.21 cm−1 for I and −11.53 cm−1 for II) in the dimeric units, with Co...Co and Ni...Ni distances of 4.397 (1) and 4.358 (1) Å, respectively, that are related to double syn–anti carboxylate bridges.

The adsorption phenomena occurring at the surface of a highly-dispersed Pt/Al2O3 catalyst for hydrogenation reactions were thoroughly investigated in the gas-phase by transmission IR spectroscopy and in the liquid-phase by...