Modulation of Mössbauer radiation by pulsed laser excitation

Experimental results on the observation of the modulation of Mössbauer radiation by pulsed laser radiation are presented. The time domain spectra agree well with the model of the frequency modulation of the Mössbauer radiation during the passage of the radiation through a vibrating resonance medium. The proposed methodology may be used for the study of opto-acoustic phenomena.     

A Curtin–Hammett pentamethylene chain symmetrization process in the Bergman cyclization of an 11‐membered ring enediyne

Pentamethylene chain conformational effects for the Bergman cyclization of the 11‐membered ring enediyne, (3Z)‐3‐cycloundecene‐1,5‐diyne, 2, are examined theoretically with unrestricted Becke, three‐parameter, Lee–Yang–Parr/6‐31 G(d,p) calculations. A C₁ symmetric enediyne conformation was found to be the global minimum, where its nonsymmetric pentamethylene chain prevented π‐orbital alignment of the acetylene groups for C–C σ bond product formation. The Bergman cyclization of 2 was found to be conformationally dependent. In a Curtin–Hammett type process, the C₁ symmetric 2 inverts to one of the C_S or C₂ symmetric conformers required for the Bergman cyclization, which produced a C_S or C₂ symmetric 1,4‐diradical intermediate. The activation energy for the cyclization is slightly higher to reach the C₂ symmetry diradical compared with the C_S symmetry diradical. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis and structure of new chlorine containing calix[4]resorcinols

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Correction to: Lithium ion conductivity of solid solutions based on Li8ZrO6

Journal of Solid State Electrochemistry - Lithium ion conductivity of lithium hexaoxozirconate Li8ZrO6 doped by Mg2+, Sr2+, Nb5+, V5+, and Ce4+ cations was studied using impedance spectroscopy. The...     

A Convenient Method of N-Methylphthalimide Synthesis

We suggest a convenient method to obtain N-methyiphthalimide with a high yield in the reaction of phthalic anhydride with aqueous methylamine.     

Synthesis of 5,10,15,20-tetra[6' -nitro-1,3,3-trimethylspiro- (indolino-2,2' -2H-chromen-5-yl)]porphyrin and its metal complexes

A new 5,10,15,20-tetrasubstituted porphyrin containing four 6’-nitro-1,3,3-trimethylspiro(indolino-2,2’-2H-chromene) substituents and its complexes with Zn²⁺ and Cu²⁺ ions were prepared and characterized by physicochemical methods of analysis.     

Design of pincer complexes based on (methylsulfanyl)acetic/propionic acid amides with ancillary S‐ and N‐donors as potential catalysts and cytotoxic agents

Pincer complexes featuring readily tunable tridentate ligand frameworks comprise one of the most actively studied classes of organometallic and metal–organic compounds and find extensive use in catalysis, organic synthesis, materials science, and other fields of chemistry and allied disciplines. Currently growing attention is devoted to non‐classical ligand scaffolds, such as functionalized carboxamides, which offer multiple options for directed structural modifications. In this study, the reactions of (methylsulfanyl)acetyl and propanoyl chlorides with 2‐(aminomethyl)pyridine, 2‐(2‐aminoethyl)pyridine, 8‐aminoquinoline and 2‐(diphenylthiophosphoryl)aniline afford a series of new pincer‐type ligands based on functionalized carboxamides. The ligands obtained readily undergo direct cyclopalladation under the action of PdCl₂(NCPh)₂ in dichloromethane at room temperature, resulting in Pd(II) pincer complexes with N,N,S‐ and S,N,S‐donor sets. Importantly, some of the cyclopalladated derivatives can also be produced efficiently under solvent‐free conditions according to the approach recently developed by our group. The complexes obtained have been tested for cytotoxicity against several human cancer cell lines and catalytic activity in the model Suzuki reaction. The results have been compared to those for the related Pd(II) pincer complexes to define the main structure–activity relationships and to outline the most promising structures for further investigations.     

α-Diphenylphosphino-N-(pyrazin-2-yl)glycine as a ligand in Ni-catalyzed ethylene oligomerization

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