水和非水体系现场电化学-电子自旋共振测量——电解池制作和初步结果

A simultaneous electrochemical-electron spin resonance(SEESR)cell has been designed. It is easily fabricated and operated and can be used for either aqueous or nonaqueous determation.Using this aparatus, the ESR signals were observed for nitrobenzcne anion radicals, produced by constant potential electrolysis of nitrobenzene in acetonitrile media with 0.1M TBAP as electrolyte and in 0.5M KCl aqueous solution respectively. The hyperfine coupling constants of the nitrobenzene anion radical have been estimated which are in accordance with the literature values.     

An electron spin resonance (ESR) and simultaneous electrochemical and electron spin resonance (SEESR) spectroscopic study of motion, stability and potential controlled release of radical guests from the β-cyclodextrin inclusion polymer

The influence of molecular inclusion and separation of radical guests inside the amorphous β-cyclodextrin host polymer (β-CDP) matrices on the motion and stability as well as controlled potential release of radicals was studied by electron spin resonance spectroscopy (ESR) and simultaneous electrochemistry and electron spin resonance (SEESR) spectroscopy. A pronounced restriction of rotational motion was observed for the included stable protonated form of the 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl (4-amino-TEMPO) free radical and a partial restriction of motion of the NN,N',N'-tetramethyl-1,4-phenylenediamine (TMPD^.+) radical (generated ex situ by controlled potential electrolysis), while virtually no restriction was found in the case of the methyl (MV^.+) and heptyl viologen (HV^.+) monocation radicals as well as of the 2-nitrotoluene anion radical (2NT^.− ). The MV^.+, HV^.+ and 2NT^.− unstable radicals were electrochemically generated inside the β-CDP film coat at a Pt flag electrode. The rate of the open-circuit decay of the included unstable radicals was markedly decreased as compared with their decay at the bare electrode. It was also found that the extent of inclusion of alkyl viologens was governed by their ionic charge, i.e. the higher the charge of the ion the weaker its inclusion.     

On some problems in the theorems of alternant hydrocarbons

A number of theorems of alternant hydrocarbons presented by Dewar are proved to be wrong. A statement of the related theorem instead of Dewar's is presented.     

Analysis of Spontaneous Electrochemical Oscillations by the Wavelet Transformation Method

A new way of analyzing current oscillations that accompany anodic metal dissolution is presented. A wavelet transformation is used for separation and spectral analysis of singular courses—elementary components of electrochemical oscillation recordings. A method of obtaining oscillation energy distribution analogous to the spectral power density function is presented. It is shown that the chaotic component (Shil'nikov chaos) can be separated from the deterministic component of the described process.     

Image states: Idea and theoretical development

The concept and theoretical development of image states is reviewed. A brief summary of calculations of binding energies and effective masses is presented together with a more detailed discussion of the lifetime of such states. A brief discussion of the dependence of the linewidths with the surface response function is presented.     

A Note on Mathematical Relationships Among Bond-Torsion Force Fields

A set of mathematical relationship between torsion potential functions such as trigonometric and Fourier series is presented herein. A harmonic approximation form is also introduced, and its stiffness constant is related to the parameters of trigonometric and Fourier series. Mathematical relationships between various force field parameters are presented in the form of conversion matrices.     

A new three-component one pot reaction of trinitromethane, epoxides and alkenes via dinitronitronates: synthesis of highly functionalized 3,3-dinitroisoxazolidines

A novel approach to acyclic alkyldinitronitronates using nucleophilic opening of epoxides with the trinitromethyl anion is presented. The scope and limitations of this synthetic procedure are presented. A series of highly functionalized 3,3-dinitroisoxazolidines were synthesized as mixtures of diastereomers.     

An algorithm for self-consistent field MO LCAO computations on conjugated systems with allowance for configuration interaction

The Pariser-Parr-Pople method is described briefly. An algorithm is presented for quantum-mechanical computation of molecular structures. A program for the BESM-2M computer is presented.     

A second-quantization approach to the analytical evaluation of response properties for perturbation-dependent basis sets

A general theory for response properties is presented which is applicable to perturbations affecting the molecular basis set, notably nuclear derivatives. A perturbation-independent Fock space is introduced, and the necessary reorthonormalization of a truncated basis set after a perturbation is explicitly incorporated in the Hamiltonian. Explicit formulas for MCSCF first- and second-order properties are presented, and some computational aspects are briefly discussed. A brief comparison with previous results is given.     

C-F Bond Formation for the Synthesis of Aryl Fluorides

A selection of carbon-fluorine bond-forming reactions is presented with particular focus on transition metal-mediated fluorination. A brief summary of conventional fluorination reactions is followed by a discussion of fluorination reactions mediated by palladium and silver. Investigations into the mechanism as well as the conceptual difficulty associated with transition metal-mediated carbon-fluorine bond formation are presented.