Condensation metallosupramolecular polymers containing main-chain 2,2′-bipyridine and 2,2′:6′,2″-terpyridine moieties

Methods of preparing diverse metallosupramolecular polymers containing 2,2′-bipyridine and 2,2′:6′,2″-terpyridine moieties in main chains and their properties have been considered and analyzed. It has been shown that these polymers offer new possibilities for the design of materials possessing valuable specific characteristics.     

Force fields and vibrational spectra of M2O and MOH (M = Li,Na) molecules according to data from nonempirical MO-LCAO-SCF calculations

The geometric structure, force fields, and vibrational spectra of M₂O and MOH (M=Li, Na) molecules have been investigated. The size of the d basis on the oxygen atom has a significant influence only on the frequency of the deformation vibration ₃. Experimentally unknown constants of the molecules considered have been evaluated.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 22, No. 6, pp. 724–728, November–December, 1986.     

Thermodynamics of condensation of phthalonitrile with m-phenylenediamine

Conclusions The reaction of phthalonitrile condensation with m-phenylenediamine is thermodynamically allowed at temperatures from 250° to 500°K, and its equilibrium is almost completely shifted toward the formation of the macroheterocycle.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 779–787, April, 1984.     

The addition of hydrogen chloride to alk-1-enes in the presence of dicyclohexyl peroxydicarbonate,iron pentacarbonyl,and ferric chloride

Russian Chemical Bulletin -     

Deuteron magnetic resonance study of single crystals of NaDSeO3

A deuteron magnetic resonance study of a single crystal of NaDSeO₃ at room temperature is reported. The observed electric field gradient tensors correspond to two nonequivalent hydrogen bonds. The quadrupole coupling constants ($\text{eQq}\text{h}$) and asymmetry parameters (η) are found to be 172.8 and 0.07 kHz for D(1), and 152.5 and 0.08 kHz for D(2). D(2) are ordered, but D(1) are found to be dynamically disordered. The DMR results are consistent with recent X-ray reinvestigation. No phase transitions have been encountered in the temperature range 336 to 77 K.     

Synthesis and properties of polycondensation polymers from compounds with asymmetric functional groups

The effect of conditions of polycondensation on the structure of polymers formed from monomers with symmetric and asymmetric functional groups by nonequilibrium polycondensation has been studied for the system with acceptor-catalytic polyesterification of β-hydroxyethyl ethers of bisphenols and terephthalic acid chloride in the presence of triethylamine. Polymers with statistical or regular arrangement of diol residues in the chain can be produced in such systems, depending on the way in which starting compounds are introduced in the reactor. A difference in the reactivity of functional groups in an asymmetric monomer is not sufficient to produce polycondensation polymers with a regular structure. Gradual introduction of the symmetric monomer is essential to yield polymers with predominant “head-to-head” (“tail-to-tail”) configurations. Some properties of the resulting polymers have been studied. Polymers with ordered residues of the asymmetric monomers in the macromolecules have higher softening temperatures and an increased tendency for crystallization than the statistic polymers.     

L-asparaginase bound in a polyacrylamide gel

Summary The enzyme L-asparaginase fromE. coli has been included in polyacrylamide gel, and some of its properties have been investigated: stability, pH dependence, heat stability, K_m. It has been shown that the enzymegel obtained has a better stability then the native enzyme.Institute of Organic Synthesis, Academy of Sciences of the Latvian SSR, Riga. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 382–384, May–June, 1976.