Singular Integral Operators in Generalized Morrey Spaces on Curves in the Complex Plane

We study the boundedness of the Cauchy singular integral operators on curves in complex plane in generalized Morrey spaces. We also consider the weighted case with radial weights. We apply these results to the study of Fredholm properties of singular integral operators in weighted generalized Morrey spaces.     

Structure and properties of ionic fullerene complex Co(+)(dppe)2·(C60˙-)·(C6H4Cl2)2: distortion of the ordered fullerene cage of C60˙- radical anions

New ionic complex {Co(+)(dppe)(2)}·(C(60)˙(-))·(C(6)H(4)Cl(2))(2) (1) was obtained by the reduction of a Co(dppe)Br(2) and C(60) mixture by TDAE in o-dichlorobenzene followed by precipitation of crystals by hexane. Optical and EPR spectra of 1 indicated the formation of C(60)˙(-) radical anions and diamagnetic Co(+)(dppe)(2) cations. The structure of 1 solved at 100(2) K involves chains of C(60)˙(-) arranged along the lattice a-axis with a center-to-center distance of 10.271 ?. The chains are separated by bulky Co(+)(dppe)(2) cations and solvent molecules. All components of 1 are well ordered allowing the distortion of the C(60)˙(-) radical anion to be analyzed. An elongation of the C(60)˙(-) sphere by 0.0254(2) was found. It is essentially smaller than those in the salts (Cp*(2)Ni(+))·(C(60)˙(-))·CS(2) and (PPN(+))(2)·(C(60)(2-)) with greater distortion of the fullerene cage. The calculation of the electronic structure of fullerene by the extended Hückel method showed slight splitting of the C(60) LUMO, due to the distortion, by three levels. Two levels are located 180 and 710 cm(-1) higher than the ground level. The averaged 6-6 and 5-6 bonds in C(60)˙(-) with lengths of 1.397(2) and 1.449(2) ? are close to those determined for the C(60)(2-) dianions in (PPN(+))(2)·(C(60)(2-)), but are slightly longer and shorter, respectively, than the length of these bonds in neutral C(60).     

Dielectric spectra broadening as the signature of dipole-matrix interaction. I. Water in nonionic solutions

Whenever water interacts with another dipolar entity, a broadening of its dielectric relaxation occurs. Often this broadening can be described by the Cole-Cole (CC) spectral function. A new phenomenological approach has been recently presented [A. Puzenko, P. Ben Ishai, and Y. Feldman, Phys. Rev. Lett. 105, 037601 (2010)] that illustrates a physical mechanism of the dipole-matrix interaction underlying the CC behavior in complex systems. By considering the relaxation amplitude Δε, the relaxation time τ, and the broadening parameter α, one can construct a set of 3D trajectories, representing the dynamic behavior of different systems under diverse conditions. Our hypothesis is that these trajectories will contribute to a deeper understanding of the dielectric properties of complex systems. The paper demonstrates how the model describes the state of water in aqueous solutions of non-ionic solutes. For this purpose complex dielectric spectra for aqueous solutions of D-glucose and D-fructose are analyzed.     

Stable alkanes containing very long carbon-carbon bonds

The metal-induced coupling of tertiary diamondoid bromides gave highly sterically congested hydrocarbon (hetero)dimers with exceptionally long central C-C bonds of up to 1.71 ? in 2-(1-diamantyl)[121]tetramantane. Yet, these dimers are thermally very stable even at temperatures above 200 °C, which is not in line with common C-C bond length versus bond strengths correlations. We suggest that the extraordinary stabilization arises from numerous intramolecular van der Waals attractions between the neighboring H-terminated diamond-like surfaces. The C-C bond rotational dynamics of 1-(1-adamantyl)diamantane, 1-(1-diamantyl)diamantane, 2-(1-adamantyl)triamantane, 2-(1-diamantyl)triamantane, and 2-(1-diamantyl)[121]tetramantane were studied through variable-temperature (1)H- and (13)C NMR spectroscopies. The shapes of the inward (endo) CH surfaces determine the dynamic behavior, changing the central C-C bond rotation barriers from 7 to 33 kcal mol(-1). We probe the ability of popular density functional theory (DFT) approaches (including BLYP, B3LYP, B98, B3LYP-Dn, B97D, B3PW91, BHandHLYP, B3P86, PBE1PBE, wB97XD, and M06-2X) with 6-31G(d,p) and cc-pVDZ basis sets to describe such an unusual bonding situation. Only functionals accounting for dispersion are able to reproduce the experimental geometries, while most DFT functionals are able to reproduce the experimental rotational barriers due to error cancellations. Computations on larger diamondoids reveal that the interplay between the shapes and the sizes of the CH surfaces may even allow the preparation of open-shell alkyl radical dimers (and possibly polymers) that are strongly held together exclusively by dispersion forces.     

Semileptonic (lepton,neutrino and jets) <Emphasis Type="Italic">WW</Emphasis>/<Emphasis Type="Italic">WZ</Emphasis> resonances searches at √<Emphasis Type="Italic">s</Emphasis> = 8 and 13 TeV with the ATLAS detector at the LHC

This talk presents the analyses results of the diboson (WW or WZ) resonances production search in pp collisions at √s = 8 and 13 TeV with the ATLAS detector at the LHC with the semileptonic final state. As benchmark signal models Randall-Sundrum bulk model for KK G* → WW and Heavy Vector Triplet model for W′ → WZ and Z′ → WW are used. No significant excess for diboson resonances production is observed and upper limits on the production cross section times branching fraction of G*, W′ and Z′ are determined at 95% CL.     

Novel structural type of bridged urea derivatives bearing azatricyclo[4.3.1.03,8]decane moiety

Structural Chemistry - In an attempt to synthesize 4-thia-6-azatricyclo[5.3.1.13,9]dodecan-5-imine as putative antihypotensive agent with prolonged effect, a reaction of...     

Stereochemical non-rigidity of N-(dimethylhalogenosilylmethyl)-N-(1-phenylethyl) acetamides in solutions

The structure and dynamic behavior of (O-Si)-chelate N-(dimethylhalogenosilyl)methyl acetamides of the type MeC(O)N(CH(Ph)Me)CH₂ SiMe₂ X, where X = F, Cl, Br with the OSiC₃X coordination set, were studied by multinuclear (¹H, ¹³C, ¹⁷O, ²⁹Si) and dynamic ¹H NMR spectroscopy. Ligand permutation at silicon was detected. The observed influence of the solvent, nucleofugacity of the X substituent and the external nucleophile on the calculated values of the free energies of activation testify to the dissociative and/or associative mechanisms of the process, but including the stages in which the regular (pseudo-rotation or ‘turnstile’) mechanism takes place. At lower temperatures (up to −90°C) the ¹H, ¹³C, ²⁹Si NMR spectra of N-(dimethylchlorosilyl)methyl acetamide contain the signals of two species of unequal intensity. This effect was explained by an equilibrium between monomers containing the intramolecular O → Si bond and dimers with a hexacoordinate silicon and the bridging chlorine atoms.     

Synergetic Effect of Mo6 Clusters and Gold Nanoparticles on the Photophysical Properties of Both Components

Photodynamic and photothermal therapies (PDT, and PTT, respectively) are promising candidates for multimodal anticancer therapies (i.e., combinations of therapies), since their action is based on mechanisms that generally cannot be resisted by cancer cells, that is, generation of highly oxidizing oxygen species and high temperature, respectively. Herein, hybrid materials that combine octahedral molybdenum clusters as potential PDT agents and plasmonic spherical gold nanoparticles (AuNPs) as PTT agents are reported. Partial overlap of the photoemission spectrum of the cluster and the surface plasmon resonance band of the AuNPs facilitates energy transfer between the photoactive components, which resulted in synergetic enhancement of their photophysical properties. Specifically, by careful selection of the spacing between the cluster and the gold nanoparticle, a significant increase in luminescence and photosensitizing properties of the cluster was achieved in comparison with similar, but gold-free, particles. On the other hand, the cluster complex facilitated energy conversion to heat by gold particles and hence increased the heating rate under laser irradiation.     

Molecular Design of Silicon-Containing Diazenes: Absorbance of E and Z Isomers in the Near-Infrared Region

The effective use of photochromic systems based on azo compounds in a number of applications, especially biomedical and pharmacological ones, is impeded by the unresolved problem of their E⇆Z isomerization in the near-IR region, NIR (780–1400 nm). We have demonstrated at the TD-DFT, STEOM-DLPNO-CCSD and CASSCF-NEVPT2 levels of theory that the presence of a silylated diazene core −Si−N=N−Si− with three-, tetra- or five-coordinated silicon atoms practically guarantees the absorption of the E and Z forms of such derivatives in NIR and the amazing (185–400 nm) separation of their first absorption bands. In particular, the maximum λ₁ of the first n→π* band of the E isomer of azosilabenzene ASiB is at ∼1030 nm, while for the Z isomer λ₁≅1340 nm. Based on the found bistable azo compounds ( ASiB , bis(silyl)- SiD and bis(silatranyl)- SaD diazenes) and their derivatives with E and Z absorption in NIR, unique photoswitches can be created for a number of applications, in particular, for photothermal therapy.     

Synthesis and antihypotensive properties of 2-amino-2-thiazoline analogues with enhanced lipophilicity

In a search of nitric oxide synthase inhibitors with prolonged vasoconstrictive activity, a series of lipophilic cyclohexafused 2-amino-2-thiazolines was obtained via cyclization of tert-butyl- or benzoyl-substituted N-(cyclohex-2-en-1-yl)thioureas. The crystal structure of intermediate N-[(3aRS,7aSR)- 3a,4,5,6,7,7a-hexahydro-1,3-benzothiazol-2-yl]benzamide hydrobromide was determined by X-ray analysis. One compound was found to cause pronounced and prolonged vasoconstrictive effect after single injection to the Wystar rats with lipopolysaccharide induced acute endotoxic (vasodilatation) shock.