Kinetics and Mechanism of Palladium Electrodeposition from Alkaline Solutions of Palladium(II) Bisethylenediamine Complexes

The electroreduction kinetics of Pd(en)²⁺ ₂ complexes (0.01 M) is studied on a rotating disk electrode of Pd by recording CVA at 25, 50, and 70°C in solutions of pH 12–13 at ethylenediamine concentrations of 0.03–1.0 M. Established is a diffusion nature of limiting currents, from which diffusion coefficients for Pd(en)²⁺ ₂ complexes are calculated. The Pd electrode capacitance, determined by a pulsed galvanostatic method, is used for taking into account the true surface areas of electrolytic Pd deposits. Parameters of the slow electrochemical stage, which involves Pd(en)²⁺ ₂ complexes, are determined. The temperature dependence of the rate constant of cathodic reduction of Pd(en)²⁺ ₂ complexes is used for calculating an apparent activation energy. An electroreduction mechanism of Pd(en)²⁺ ₂ complexes on a Pd electrode is discussed.     

Isomerization of α-acetylenic ketones

A method is suggested for isomerization of -acetylenic ketones with migration of the oxo group from position 1 to position 3 and of the triple bond from position 2 to position 1 of the ketoacetylenic fragment; it consists of addition of Et₂NH at the triple bond of the ketone, conversion of the adduct to the imminium salt with POCl₃, followed by alkaline hydrolysis. The isomerization is achieved in one preparative stage without isolation of intermediate compounds.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2094–2098, September, 1990.     

Choline esters of alkylenebisphosphonic acids

The reaction of the acid chlorides of alkylenebisphosphonic acids with ethylene glycol and ethylene chlorohydrin gave ethylene glycol and -chloroethyl esters of alkylenebisphosphonic acids. The quaternization of these products leads to choline esters of alkylenebisphosphonic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1424–1429, June, 1990.     

Bromination of 3-acyl-2-aminoindoles

Unlike 3-acylindoles, 3-acyl-2-aminoindoles display high selectivity on being electrophilically attacked in the benzene ring, and are substituted at the 6-position. At the same time, an unco-subsitution of the acyl group takes place (to the greatest extent — the formyl group). Direct bromination of 3-acyl- and 3-cyano-2-aminoindoles provides the 6-bromo- and 6,4-dibromo-2-aminoindoles and their derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 486–490, April, 1990.     

A spin-dependent unitary group approach to many-electron systems

In this article we derive a segment-level formula for the matrix elements of the U(2n) generators in a basis symmetry adapted to the subgroup U(n) × U(2) (i.e., spin-orbit basis), for the representations appropriate to many-electron systems. This enables the direct evaluation of the matrix elements of spin-dependent Hamiltonians.     

Halogenation of isoflavones using thionyl and sulphuryl chlorides

The reactions of thionyl and sulphuryl chlorides on isoflavones have been found to give a number of new chloroisoflavones and isoflavanones, whose structures have been elucidated on the basis of their spectral analytical data.     

On the behavior of α-brominated dimethyl o-benzenediacetate toward nitrogen nucleophiles. Part II. Reaction of dimethyl α-bromo-o-benzenediacetate with hydrazines

Dimethyl α-bromo-o-benzenediacetate ( 1 ) condensed with hydrazine and acetylhydrazine to give respectively 1-carbomethoxy-2-amino-1,4-dihydro-3-(2H)isoquinolinone (2) and its N-acetyl derivative ( 9 ). Replacement of the bromine atom of 1 with the N-1-methylhydrazino ( 3 ) and the N-1-phenylhydrazino ( 5 ) groups occurred by allowing 1 to react respectively with methylhydrazine and phenylhydrazine. In the latter case alkylation by 1 at the N-2 also occurred which led to the formation of the 2-phenylaminoisoquinolinone ( 8 ). Derivatives 3 and 5 smoothly cyclized to the 1-earbomethoxy-5(H)-1,2,3,4-tetrahydro-2,3-benzodiazepin-4-ones 4 and 6 . A series of derivatives of 2 were also pharmacologically tested as antiinflammatory and CNS depressant agents.     

Phase diagram and X-ray diffraction analysis of the acrylic acid–acrylamide system

The phase diagram of the acrylic acid–acrylamide system as determined by DTA and the supporting x-ray diffraction data are presented. This diagram shows that the system forms a 1 : 1 addition compound which decomposes above 0°C. There is also one eutectic point at a 67 mole-% acrylic acid composition.     

Über die Konstitution eines Nebenalkaloides aus Adhatoda vasica Nees

Zusammenfassung Das in der vorangehenden Mitt. vonE. Späth undF. Gandini-Kesztler beschriebene Nebenalkaloid wird auf synthetischem Wege mit dem 6-Hydroxy-peganin identifiziert. Die phenolische OH-Gruppe steht also, bezogen auf Formel III, nicht an der Stelle, welche dem CH₃O des Harmins entspricht.     

Accurate local spin-polarized exchange potential: Reconciliation of generalized Slater and Kohn–Sham methods

Using simple physical arguments, a local spin-polarized exchange potential, V_xσ, is constructed from the single-particle Hartree–Fock (HF ) potentials (generalized Slater method) that reduces to the usual Kohn–Sham (KS ) result in the uniform gas limit. Numerical results for 10 closed subshell atoms demonstrate that the total energy calculated employing this V_xσ is closer to the exact KS results than those of other standard exchange approximations with electron densities and highest occupied orbital eigenvalues that closely approximate the HF results.