Colloidal Systems on the Basis of Novel Reactive Surfmers

Summary: New anion surfmers of the family of maleic acid asymmetrical esters have been synthesized. Some of its features in the process of emulsion copolymerization with styrene have been studied. The characteristics of covering, obtained on the basis of such latexes of new generation have been investigated as well.     

One-step synthesis of novel photochemically bifunctional compounds of the spiropyran class

The one-step reaction of 5-amino-1,3,3-trimethyl-2-methylideneindoline with two equivalents of different ortho-hydroxy-substituted aromatic aldehydes afforded novel photochemically bifunctional compounds. Molecules of these compounds include two functionally different fragments: the substituted azomethine (salicylideneimine or hydroxynaphthyl-methylideneimine) fragment in which intramolecular proton transfer can be induced by electronic excitation and the spiropyran fragment in which the O-C_spiro bond can dissociate upon UV-light absorption to form the merocyanine form. No conjugation between the azomethine and pyran fragments is observed in the initial state of the molecule. The compounds synthesized manifest the photochromic properties and luminescence.     

Synthesis and kinetics of photochemical reactions of novel bifunctional salicylideneiminospironaphthoxazines

A series of novel photochemically bifunctional compounds was synthesized. Their molecules combine the photochromic spironaphthoxazine fragment with a salicylideneimine fragment containing various substituents. The latter can undergo intramolecular proton transfer in the electron-excited state. Photolysis products of three types, namely, open merocyanine forms having an enol or cis-keto form of the salicylideneimine moiety and a trans-keto form with the closed spiro fragment, were detected using pulse photolysis technique in toluene and methanol solutions. The spectral kinetic characteristics of the photoproducts were studied, and their quantum yields were measured. The effects of substituents in the salicylideneimine fragment and the solvent nature were discussed.     

Synthesis,Structure, and Spectral Properties of 3,5-Di-tert-butyl-1,2-benzoquinone 3-Hydroxynaphthoyl Hydrazone and Its Complexes with Zn(II), Cd(II), Ni(II), and Co(II)

Russian Journal of General Chemistry - Novel complexes of Zn(II), Cd(II), Ni(II), and Co(II) with 3,5-di-tert-butyl-1,2-benzoquinone 3-hyd-roxynaphthoyl hydrazone have been synthesized....     

Excited-state intramolecular proton transfer in 2,4,5-triarylimidazole molecules

Excited-state intramolecular proton transfer (ESIPT) in the 2,4,5-triarylimidazole molecules was studied by spectral-luminescent technique. For 4,5-diphenyl-(2-hydroxyphenyl)imidazoles, the ESIPT occurs in both liquid and glassy matrices at 77 K. For 4,5-diphenyl-(2-hydroxynaphthyl)imidazole, the ESIPT requires rotation of molecular fragments and is not observed at 77 K.     

Spectral and kinetic parameters of transient species in the photolysis of naphthylmethylideneiminospironaphthopyran by excitation at different wavelengths: Nano- and femtosecond laser photolysis

Intramolecular processes occurring in a photobifunctional compound (PBC) comprising the spironaphthopyran and hydroxyazomethine moieties have been studied in methanol solutions by femtosecond laser photolysis using light with wavelengths of 340 and 490 nm. At the excitation wavelength of 490 nm, the cis-trans photoisomerization in the azomethine moiety occurs in the S₁ state. In the case of PBC photolysis with 340-nm light, the opening of the spiro bond of the spiropyran moiety (formation of the X form) also takes place during relaxation of the S_n state to the S₁ state followed by isomerization to the merocyanine form. The spectral and kinetic characteristics of different electronically excited have been were determined. The data have been compared with those of nanosecond laser photolysis.     

Kinetics of coloration of electrochromic tungsten oxide films produced by cathodic electrodeposition

The dependence of the kinetic characteristics of electrochromic indicator devices based on films of amorphous tungsten oxide α-WO₃ on the speed of reversible coloration of their working electrode with a film of this kind was studied.     

Determination of configuration of products of nucleophilic addition to activated acetylenes by the NMR method

Conclusions It was shown that the stereospecificity of SSCC³ _C,H ^trans > ³J _C,H ^cis is applicable as a configurational test for di- and trisubstituted alkenes R₂E(Y)C=C(X)H with various heteroatomic substituents (E=N, P, S) and activating groups (X=CO₂Alk, CN at Y=H, and X=Y=CO₂Alk, CN, CF₃).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 779–783, April, 1988.     

Nitration of photochromic spirophenanthroxazine

Nitration of photochromic spirophenanthrooxazine with three different reagents (cupric nitrate, NaNO₂ in acetic acid, and HNO₃-H₂SO₄) was studied. The major reaction products were specified and characterized by ¹H and ¹³C NMR and mass spectra. The mechanisms of their formation were proposed. Only the nitration with a mixture of nitric and sulfuric acids yielded a photochromic product containing the nitro group in the phenanthrene fragment. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1670–1677, July, 2005.