STM Study of Self-Organization of 10CB Molecules on Au(111) Surface

We report the scanning tunnelling microscopy (STM) observation of a self-organization of 4-cyano-4′-n-decylbiphenyl (10CB) molecules on the reconstructed Au(111) surface. The self-organized monolayers were obtained by the deposition from a liquid. We revealed a row-like dimer structure with regularly arranged kinks within each dimer row. The separation between neighbor kinks is equal to 4 or 5 intermolecular distances. STM-images with intramolecular resolution showed that the association of molecules in dimers is due to the interaction between cyano groups. The obtained results are discussed in terms of the balance between the molecule-molecule and molecule-substrate interactions and are supported by the results of DFT calculations.     

Ore-type conditions implying 2-factors consisting of short cycles

For every graph G, let . The main result of the paper says that every n-vertex graph G with contains each spanning subgraph H all whose components are isomorphic to graphs in . This generalizes the earlier results of Justesen, Enomoto, and Wang, and is a step towards an Ore-type analogue of the Bollobás-Eldridge-Catlin Conjecture.     

A new approach to construction of isoindolo[1,2-a]isoquinoline alkaloids Nuevamine, Jamtine, and Hirsutine via IMDAF reaction

The interaction between 1-furyl-1,2,3,4-tetrahydroisoquinolines and unsaturated acids derivatives (acryloyl, methacryloyl, and crotonoyl chloride, maleic and citraconic anhydride) was studied. It was shown that the reaction proceeds via amide formation and subsequent intramolecular Diels-Alder reaction of the furan (IMDAF). The [4+2] cycloaddition proceeded under mild reaction conditions (25-80 °C) and afforded only the exo-adduct in a high yield. With this method, a new approach to the isoindolo[1,2-a]isoquinoline system, the basic structural element of alkaloids Jamtine, Hirsutine, and Nuevamine, is proposed.     

Contribution to the nonlinear theory of sound and hydrodynamic turbulence of a compressible liquid

The interaction of sound with hydrodynamic turbulence has been studied in detail. The sound absorption decrement, the correlation time and length and the frequency diffusion coefficient for the acoustic wave packet are calculated. The spectral composition of the sound radiated by a unit, turbulent volume and the spectral energy density of sound in equilibrium with the turbulence are studied. The region of applicability of the kinetic equation for sound with a linear dispersion low is found.     

On neighborly families of convex bodies

A family of convex bodies in E^d is called neighborly if the intersection of every two of them is (d-1)-dimensional. In the present paper we prove that there is an infinite neighborly family of centrally symmetric convex bodies in E^d, d 3, such that every two of them are affinely equivalent (i.e., there is an affine transformation mapping one of them onto another), the bodies have large groups of affine automorphisms, and the volumes of the bodies are prescribed. We also prove that there is an infinite neighborly family of centrally symmetric convex bodies in E^d such that the bodies have large groups of symmetries. These two results are answers to a problem of B. Grünbaum (1963). We prove also that there exist arbitrarily large neighborly families of similar convex d-polytopes in E^d with prescribed diameters and with arbitrarily large groups of symmetries of the polytopes.     

Synthesis and properties of 1,3-diphenyl-5-(benzothiazol-2-yl)-6-R-verdazyls

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Structures and tautomeric interconversions of anthraquinone imine derivatives

Substituted 1-hydroxy-9,10-anthraquinone-9-imines have been found to exhibit tautomeric interconversions between the 9,10- and 1,10-quinonoid forms in the solid state as well as in solution. Single-crystal X-ray crystallography was used to study the structures of 4-(N-acetyl-p-tolylamino)-9-amino-1,10-anthracenedione and 4-hydroxy-1-phenylamino-10-mesitylimino-9(10H)-anthracenone at ambient and low temperatures. The former compound gave crystals belonging to the monoclinic space group P2_l/c and, at 295 K,a=9.684(2),b=16.371(3),c=12.097(2) å,=110.41(1), V=1797 å³,Z=4, R(F)=0.042, and GOF=0.863. The latter compound gave crystals belonging to the monoclinic space group C2/c and, at 295 K,a=38.158(8),b=6.322(2),c=19.325(4) å,=101.78(2),V=4564 å³,Z=8, R(F)=0.052, and GOF=0.981, while at 150 K,a=37.852(6),b=6.245(1),c=19.235(4) å,=102.81(1),V=4434 å³,R(F)=0.047, and GOF=1.006. Comparison of the geometric parameters of the two compounds illustrates the considerable zwitterionic nature of the first, a distinctive feature of which is a very short bond N(9)-C(9) whose length is essentially equal to that of a double bond. Molecular modeling studies using AMI semiempirical calculations were shown to be capable of satisfactorily reproducing the energetics of the tautomeric equilibrium once the medium effect was taken into account.