Dealkylation ofpara-nitrophenyldimethyl thiophosphate in micellar and liquid-crystalline media of then-decylammonium chloride-n-decylamine-water system

The kinetics of decomposition of p-nitrophenyldimethyl thiophosphate (1) were investigated spectrophotometrically in the n-decylammonium chloride-n-decylamine-water system (DAC-DA-H₂O), in which micellar or lamellar liquid-crystalline phases are formed as a function of the concentration of components. It was shown that1 is dealkylated in both phases. An increase in the surface charge density of associates decreases the rate of dealkylation. The activation energy in the lamellar phase is significantly higher than in the micellar phase.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1042–1048, May, 1992.     

Synthesis and properties of thiazole halohydrazones. 2. Interaction of 2-α-chlorobenzylidenehydrazino-4-ethoxy-carbonylthiazole with nucleophiles

In the interaction of 2--clzlorobenzylidenehydrazino-4-ethoxycarbonylthiazole with nucleophiles, two competing reactions take place. 1) nucleophilic replacement of the chlorine atom to form the corresponding substitution product; 2) elimination of a hydrogen chloride molecule, concluding in cyclization of the intermediate nitrilimine to form 3 phenyl-5-ethoxycarbonylthiazolo(2, 3-c]-1, 2, 4-triazole. The direction taken by the interaction depends on the nature of the nucleophile and is determined primarily by the ratio of basicity and nucleophilicity of the agent.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, 256–259, February, 1994. Original article submitted December 30, 1993.     

Synthesis and properties of thiazole halohydrazones. 1. Synthesis and interaction of 2-α-chlorobenzylidenehydrazino-4-ethoxycar-bonyl-thiazole with triethylamine in the presence of dipolarophiles

In the interaction of 2--chlorobenzylidenehydrazino-4-ethoxycarbonylthiazole with triethylamine, a nitrilimine is formed as an intermediate that does not react with dipolarophiles, but rather undergoes intramolecular 1, 5-dipolar cyclization to form 3-phenyl-5-ethoxycarbonylthiazolo[2,3-c]-1,2,4-ttiazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, 253–255, February, 1994. Original article submitted November 30, 1993.     

On the nematic-nematic phase transition in mixtures composed of sheet-shaped palladium organyls and apolar organic solvents

The three sheet-shaped palladium organyls 1a-c exhibit lyotropic nematic properties in apolar organic solvents. The occurrence of two nematic lyomesophases was verified by the investigation of the orientational properties of these liquid crystalline systems. In cells with obliquely deposited SiO_x layers, the director of the high temperature phase N₂ is aligned in a homogeneous, planar manner. In the low temperature phase N₁, a different orientational pattern is observed. The specific pattern type depends on the deposition conditions of the SiO_x layers. In samples homeotropically aligned in the N₂ phase, the director is tilted away from the cell normal after the transition into the N₁ phase. These changes of orientation are reversible. The experimental observations presented here support our proposed model for the structural change at the nematic-nematic phase transition.     

Synthesis and Properties of Copper Tetra-4-lauryloxyphthalocyanine

Copper tetra-4-lauryloxyphthalocyanine was synthesized. Its electronic absorption spectra show that the complex is associated in organic solvents. The shape of the spectrum and the positions of the absorption bands are virtually independent of the solvent. The compound exhibits thermotropic and lyotropic mesomorphism.     

Metal Phthalocyanines with Undecyloxybenzoic Acid Residues,and Their Mesomorphic Properties

Acylation of 4-amino-5-nitro-, 5-amino-4-bromo-, 5-amino-4-phenoxy-, 4-hydroxy-5-nitro-, 3- and 4-hydroxyphtalonitriles with p-undecyloxybenzoyl chloride gave the corresponding acyl derivatives which were used to prepare copper and cobalt phthalocyanines. Physicochemical properties of the resulting products were studied. The synthesized metal complexes all exhibit mesomorphic properties.     

Variations in Elastic and Viscous Properties in the Course of Nematic–Nematic Transition in the Tetrapalladium Organyl–Pentadecane System

Temperature dependences of elasticity constants and viscosity coefficients for nematic phases of a tetrapalladium organyl–pentadecane system were experimentally studied. At the temperature of the nematic–nematic transition, all the parameters measured were shown to vary in a stepwise manner. For the high-temperature phase N₂, the ratio of elasticity constants K ₃/K ₁ 3, whereas K ₃/K ₁ 10 for the low-temperature phase. The effective viscosity decreases by the order of magnitude in the course of the N₂–N₁ phase transition. On the basis of these results, the conclusion was made that the order parameter and length of columns, structural units of the nematic phases, sharply increase upon the N₂ N₁ transition.     

Lyotropic phase behaviour of disc-shaped tetra-palladium organyls in apolar organic solvents [1]

The lyomesomorphic behaviour in apolar organic solvents of members of two series 1 and 2 of disc-shaped palladium organyls—the syntheses of four of them are new (1d, f and 2a, e) and are described here—each carrying twelve long lipophilic chains have been studied. Their lyomesomorphism appeared to be complex and has been observed here for the first time with metal organyls. As can be seen by polarizing microscopy, most of the binary mixtures investigated here exhibit nematic properties. For two members of series 1—the chloro-bridged 1b and its bromo-analogue 1c—there is even evidence for the existence of two different nematic lyomesophases side by side showing reversible transitions between them. In ternary systems, i.e. after the addition of 2,4,7-trinitrofluorenone (TNF, a strong electron acceptor), the nematic phases are stabilized, suggesting that their mesophase structures are made up by columns with intercalated TNF molecules (charge transfer complex formation). Influences of structural features of the pallado-mesogens on the one hand and of the type of solvent on the other on the molecular self-aggregation in the observed types of lyotropic mesophase formed are discussed in detail.     

1,3,4-Thiadiazines: Methods of synthesis and reactivity (review)

The synthetic methods for 1,3,4-thiadiazines and their intramolecular rearrangement reactions are reviewed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 435–448, April, 1991.