The role of terphenyl-containing carboxylic acid in the oligomerization of aryl vinyl ketone.

The molecular structure of 8-((4''-((1R,4S)-4-butylcyclohexyl)-2'-chloro-[1,1',4',1''-terphenyl]-4-yl)oxy)oct-1-en-3-one (TERPh-VK) and 6-((4''-((1R,4S)-4-butylcyclohexyl)-2'-chloro-[1,1':4',1''-terphenyl]-4-yl)oxy) hexanoic acid (TERPh-COOH) is analyzed by FTIR spectroscopy. Vinyl ketone isolated from solution forms a thermodynamically unstable cis conformation due to probable peculiarities of the crystal structure formation. The heating of this substance above 100 °C results in the cis-trans transformation with the simultaneous opening of the vinyl double bond. The mixing of the above terphenyls in solution followed by the isolation of the solid product results in the formation of the TERPh-VK/TERPH-COOH associated species due to the H-bonding between ketone and carboxylic groups. The thermal transformation of the H-bond associated species resulted in the formation of the oligo (TERPh-VK)/TERPh-COOH associated species.

New complexes of liquid crystal discotic triphenylenes: induction of the double gyroid phase.

Electron donor-acceptor liquid crystals have been attracting considerable attention due to possible applications in optoelectronics and photonics. The creation of such charge transfer complexes is a powerful and flexible instrument for modifying the structures and properties compared to those of the initial components. In the present work, such an approach is exemplified on new complexes formed via non-covalent interactions of triphenylene discotics, namely, 2,3,6,7,10,11-hexakis(pentyloxy) triphenylene (H5T) and 2-(acryloyloxypropyloxy)-3,6,7,10,11-pentapentylox-triphenylene (TPh-3A), with an electron acceptor, ß-(2,4,7-trinitro-9-fluorenylideneaminooxy) propionic acid (TNF-carb). The structure of thin supported films of H5T, TPh-3A and their blends with TNF-carb was investigated by grazing-incidence wide-angle X-ray scattering using a synchrotron source. At room temperature, the pristine discotics crystallize in orthorhombic unit cells whereas the self-assembly of H5T and TPh-3A with TNF-carb results in a double gyroid and hexagonal phases, respectively. Formation of the double gyroid phase with the lattice parameter of 36.5 Å is driven by phase separation between the aromatic and alkyl regions of the system. It is supposed that the TNF-carb molecules of the complex are positioned in the nodes of the structure while the H5T molecules are located in the struts adjoining the nodes via triple junctions. For the hexagonal crystal of the TPh-3A/TNF-carb complex, the acceptor molecules are likely located in the interstices between the neighboring supramolecular columns of TPh-3A. The molecular structures of the blends were also explored by means of FTIR spectroscopy. A detailed FTIR spectra analysis illustrates fine changes in inter-molecular bonds. For example, the initially dimerized acceptor molecules totally disappear in the complex structures whereas in TPh-3A/TNF-carb additional H-bonds between the carboxylate group in TNF-carb and the ester group of TPh-3A form. The experimental data allows putting forward possible molecular models of the complex structures.

Solid-state synthesis, magnetic and structural properties of interfacial B2-FeRh(001) layers in Rh/Fe(001) films.

Here we first report results of the start of the solid-state reaction at the Rh/Fe(001) interface and the structural and magnetic phase transformations in 52Rh/48Fe(001), 45Rh/55Fe(001), 68Rh/32Fe(001) bilayers from room temperature to 800 °C. For all bilayers the non-magnetic nanocrystalline phase with a B2 structure (nfm-B2) is the first phase that is formed on the Rh/Fe(001) interface near 100 °C. Above 300 °C, without changing the nanocrystalline B2 structure, the phase grows into the low-magnetization modification αl' (MSl ~ 825 emu/cm3) of the ferromagnetic α' phase which has a reversible αl' ↔ α" transition. After annealing 52Rh/48Fe(001) bilayers above 600 °C the αl' phase increases in grain size and either develops into αh' with high magnetization (MSh ~ 1,220 emu/cm3) or remains in the αl' phase. In contrast to αl', the αh' ↔ α" transition in the αh' films is completely suppressed. When the annealing temperature of the 45Rh/55Fe(001) samples is increased from 450 to 800 °C the low-magnetization nanocrystalline αl' films develop into high crystalline perfection epitaxial αh'(001) layers, which have a high magnetization of ~ 1,275 emu/cm3. αh'(001) films do not undergo a transition to an antiferromagnetic α" phase. In 68Rh/32Fe(001) samples above 500 °C non-magnetic epitaxial γ(001) layers grow on the Fe(001) interface as a result of the solid-state reaction between the epitaxial αl'(001) and polycrystalline Rh films. Our results demonstrate not only the complex nature of chemical interactions at the low-temperature synthesis of the nfm-B2 and αl' phases in Rh/Fe(001) bilayers, but also establish their continuous link with chemical mechanisms underlying reversible αl' ↔ α" transitions.

[Spatial Distribution of Intron 2 of nad1 Gene Haplotypes in Populations of Norway and Siberian Spruce (Picea abies-P. obovata) Species Complex].

The length and sequence variations among intron 2 haplotypes of the mitochondrial DNA nad1 gene have been studied in the Norway and Siberian spruce (Picea abies (L.) H. Karst.-P. obovata Ledeb.) species complex. Twenty-two native populations and 15 provenances were analyzed. The distribution of the northern European haplogroup (haplotypes 721, 755, 789, 823, 857, 891, and 925) is delimited in the west by the Ural region inclusively. Haplotype 712 is widespread in populations of Siberia, in the Far East and in northeastern Russia. A novel variant of the Siberian haplogroup (780) containing three copies of the first minisatellite motif (34 bp) was found for the first time. The absence of an admixture of the northern European and Siberian haplotypes in the zone of spruce species introgression previously marked by morphological traits and nuclear allozyme loci was demonstrated. This may be evidence of the existence of a sharper geographic boundary between the two haplogroups, as compared to a boundary based on phenotypic and allozyme data. A high proportion of the interpopulation component of variation (65%) estimated by AMOVA indicates a substantial genetic subdivision of European and Siberian populations of the Palearctic spruce complex by mtDNA, which can be putatively explained by natural barriers to gene flow with seeds related, for instance, to the woodless regions of the western Siberian Plain in the Pleistocene and the probable floodplains of large rivers.

[Study on interaction of acetaldehyde with thioalcohols by infrared spectroscopy].

The reaction of acetaldehyde with thioalcohols, Mesna (monothiol) and Unithiol (vicinal dithiol) was investigated by infrared spectroscopy. Unithiol was more active in the reaction of acetaldehyde fixation than Mesna. This property may explain high efficiency of peroral administration of Unithiol for treatment of postalcoholic intoxication (hangover).