- The rotameric (R*,S*)- and (R*,R*)-biaryl-3,3′-diphthalides of polyphenylene series
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A wide range of diastereomeric pairs of biaryl-3,3′-diphthalides with aromatic (heteroaromatic) substituents of polyphenylene series (including halogen substituted) was synthesized. All of them were separated and characterized by the methods of X-ray analysis, HPLC, IR-, 1H and 13C NMR spectroscopy. It was determined that solubility, tendency to adsorption and related to it retention times, chemical shifts of equivalent hydrogen and carbon atoms of biaryl-3,3′-diphthalides diastereoisomers are determined firstly by the stereo-electronic effects of two adjacent strongly polar phthalide groups. It was shown that both in crystalline phase and in solution all the diphthalides, regardless of the chemical structure of their substituents, are existing as stable rotamers with cis or synperiplanar (chiral forms) and trans or antiperiplanar (meso-forms) conformation.
- Yangirov, Tagir A.,Fatykhov, Akhnef A.,Sedova, Elvira A.,Khalilov, Leonard M.,Meshcheryakova, Ekaterina S.,Ivanov, Sergey P.,Salazkin, Sergey N.,Kraikin, Vladimir A.
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p. 1282 - 1292
(2019/02/03)
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- Ni(0)-Catalyzed Dimerization of o-Keto Carboxylic Acid Pseudochlorides
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A new protocol of the synthesis of 3,3′-diaryl-3,3′-diphthalides by dehalogenation of o-keto carboxylic acid pseudochlorides is implemented. The feature of the new protocol is that the reaction is carried out in the presence of a zero-valent nickel comple
- Yangirov,Fatykhov,Sedova,Gileva,Khafizova,Meshcheryakova,Khalilov,Kraikin
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p. 670 - 677
(2019/07/17)
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- Gas transport coefficients of phthalide-containing high-Tg glassy polymers determined by gas-flux and NMR measurements
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The synthesis of three aromatic polymers containing phthalide cardo groups having high inherent viscosities is described. Polyimides PIC-6F and PIC-TB were prepared from a cardo diamine and two different dianhydrides, and poly(phthalidylidenearylene) (PPDAr) was prepared by a precipitative Friedel-Crafts homopolycondensation of 3-(4-biphenylyl)-3-chlorophthalide. All polymers presented high glass transition temperatures varying between 600 and 690 K. Dense membranes prepared by casting from N,N-dimethylacetamide solutions exhibited good mechanical properties and decomposition temperatures over 770 K under a N2 atmosphere. Results of gas transport measurements of O2, N2, and CO2 were comparatively analyzed based on the chemical structure of the polymers. Additionally, the solubility, diffusion, and permeability coefficients of [13C]O2 in these membranes were determined by 13C NMR spectroscopy and pulsed-field gradient NMR measurements, and the results were in good agreement with those determined with pressure-driven measurements. It was found that membranes of PPDAr exhibited the highest permeability and CO2/N2 and CO2/O2 permselectivities.
- García, Carolina,Lozano, ángel E.,De La Campa, José G.,Vygoskii, Yakov,Zolotukhin, Mihail,De Abajo, Javier,Garrido, Leoncio,Guzmán, Julio
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p. 2585 - 2592
(2015/05/13)
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