Chemiluminescence of the 9,10-anthrasemiquinone radical ion during autooxidation of 9,10-dibromoanthracene in the diphenylmethane-ButOK-DMSO system

Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 189–190, January, 1995.     

The chemiluminescence of dispiro(1,2-dioxetane-diadamantane) sorbed on silipore activated by a phenanthroline complex of Eu(iii)

The thermal decomposition of dispiro(1,2-dioxetane-diadamantane) (1) sorbed on silipore containing EuCl₃ ando-phenanthroline was investigated. The observed chemiluminescence is caused by radiative deactivation of EU^*(iii) formed according to an energy transfer mechanism. Chemiluminescence decay in the course of the decomposition of1 is exponential with the rate constantk. The activation parameters of the decomposition of1 sorbed on silipore were determined from the temperature dependence ofk. These parameters are independent of the Eu(iii) content. A kinetic compensating effect was found: the dependence of logA onE _a as a function of the content of1. The mechanism of the compensating effect is discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 447–451, March, 1995.     

Spiropyrans and spirooxazines. 3. Synthesis of photochromic 5′-(4,5-diphenyl-1,3-oxazol-2-yl)-spiro[indoline-2,3′-naphtho[2,3-<Emphasis Type="Italic">b</Emphasis>]pyran]

The reaction of 2-hydroxy-3-(4,5-diphenyl-1,3-oxazol-2-yl)-1-naphthaldehyde with 1,2,3,3-tetramethyl-3H-indolium perchlorate afforded photochromic spiro[indoline-2,3′-naphthopyran] containing a 4,5-diphenyloxazole group in position 5′ of the naphthopyran fragment. The merocyanine form of the spiropyran gave complexes with bivalent heavy cations.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 693–697, March, 2005.     

Effect of cholesterol on the properties of phospholipid membranes. 4. Interatomic voids

The properties of the interatomic voids present in fully hydrated dimyristoylphosphatidylcholine (DMPC)-cholesterol mixed membranes of different compositions are analyzed in detail using a generalized variant of the Voronoi-Delaunay method on the basis of computer simulation results. The systems investigated are chosen from both sides of the DMPC-cholesterol miscibility gap; the pure DMPC bilayer has also been included in the analysis as a reference system. The results obtained show that the empty space is organized in a more compact way, forming larger voids in the presence than in the absence of cholesterol. The voids located in the region of the rigid cholesterol rings become, on average, less spherical, oriented more parallel with the membrane normal axis with increasing cholesterol concentration, whereas an opposite effect of cholesterol is observed in the middle of the membrane among the chain terminal methyl groups. In general, the preferential orientation of the voids is found to strongly correlate with that of the molecules in the hydrocarbon phase of the membranes. The membranes are found to contain rather large voids, the volume of which can be an order of magnitude larger than the largest spherical cavities present in the systems. These voids are elongated or branching channels rather than big empty holes. The voids located among the DMPC and cholesterol molecules are lying preferably parallel with the membrane normal axis. The existence of such empty channels can be of great importance in the cross-membrane permeation of small, uncharged penetrants, in particular, of polar molecules.     

First hybrid oximehydrazonate phthalocyaninoclathrochelates: The synthesis and properties of lutetium phthalocyanine-capped cage iron(II) complexes

Ditopic oximehydrazonate iron(II) phthalocyaninoclathrochelates were synthesized by a transmetallation (a capping group exchange) reaction of the initial labile triethylantimony-capped clathrochelate iron(II) oximehydrazonates with lutetium(III) phthalocyanine as a Lewis acid. The complexes obtained were characterized using elemental analysis, PD and MALDI-TOF mass spectrometries, IR, UV–Vis, ⁵⁷Fe Mössbauer, and ¹H, ¹³C{¹H} NMR spectroscopies. An encapsulated iron(II) ion was found to be in a low-spin state. The cyclic voltammograms show oxidation and reduction waves assignable to Fe^2+/3+ couples of macrobicyclic framework and to phthalocyanine macrocycles.     

Prepeak in the structural factor. Inhomogeneous packings of Lennard-Jones atoms

This work reports on the effects of structural inhomogeneities within the models of spherical atomic packings on the radial distribution function (RDF) and the structural factor (SF). Models of inhomogeneous packings were constructed by removing some atoms from homogeneous packing according to a predetermined template. Thus various additional voids, leading to specific structural correlations of atoms on a middle scale (several atomic sizes), are introduced in the model. A dense noncrystalline packing of 27,000 Lennard-Jones atoms serves as the initial system. Three various templates were used, and models containing different fractions of additional voids were constructed with each of these templates. It is demonstrated that RDF is only slightly sensitive to such inhomogeneities; in contrast, the SF has additional peaks at small q, these peaks being notable even after removal of a small fraction of atoms. Some models yield a single narrow prepeak, which is akin to that observed in diffraction experiment for some glasses.     

Synthesis and Structure of a New Ruthenium(II) Clathrochelate and the Use of a Highly Porous Ceramic Material with an Immobilized Complex in the Oxidative Conversion of Methane

Kinetics and Catalysis - A new ruthenium(II) cage complex with polar terminal groups in the apical substituents has been synthesized; the molecular design of the complex contributes to the...     

Chemiluminescence in the reaction of the RuII trisbipyridyl complex with dimethyldioxirane

The reaction of dimethyldioxirane (1) with the Ru^II trisbipyridyl complex accompanied by chemiluminescence (CL) was studied. It is established that the intensity of CL and the rate of its decay increase proportionally with the concentration of Ru^II. The bimolecular rate constant (k ₂) of the reaction of1 with Ru^II was determined. The activation parameters (E _a and logA) for this reaction were calculated from the temperature dependence ofk ₂. The excitation yield of Ru^II* (η _Ru ^* ) was estimated. The quenching of Ru^II* by dioxirane was studied, and the bimolecular quenching constant and the coefficient of excitation regeneration were determined. It was suggested that the catalysis of the decomposition of1 and the excitation of Ru^II occurvia a mechanism of chemically initiated electron exchange. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1138–1142, June, 1997.