Photochemistry of planar four-co-ordinate palladium(II) complexes—III. Photosynthesis and crystal structure of [Pd2(PPr3n2(NCS)(SCN)2(μ-CN)]

U.V. irradiation of MeOH and CH₃CN solutions of trans-[Pd(PPr₃ⁿ)₂(NCS)₂] causes a stepwise photochemical reaction. When the solvent is CH₃CN the photoproduct can be conveniently isolated in a crystalline form. This compound has been shown, by X-ray analysis, to be a cyano bridged palladium(II) complex.     

A discrete velocity model of a gas: Global in time solutions of the BBGKY hierarchy

In the present paper we study the evolution of a system of hard disks moving in the plane with a finite number of velocities as in the framework of a discrete velocity model of the Enskog equation, proposed in previous papers. Starting from the BBGKY hierarchy of such a system we give existence and uniqueness results for the initial value problem in suitable Banach spaces. In particular, the main result presented is the global in time weak solution to the BBGKY hierarchy for local equilibrium initial data, in the thermodynamic limit.     

On the flocks of Q+(3,q)

A complete characterization of the flocks of Q⁺(3, q) is given. As an application, it follows that if q is odd, q11, 23, 59, there exist no maximal exterior sets of Q⁺ (2n–1, q) for n>2.Paper written with partial financial support of M.P.I.; the authors are members of G.N.S.A.G.A. of C.N.R.     

Evaluation of quail egg white riboflavin binding protein as a chiral selector in high-performance liquid chromatography and capillary electrophoresis

A new chiral stationary phase for high-performance liquid chromatography of quail egg white riboflavin binding protein is presented. Several chiral acidic, basic and uncharged drugs were analysed and the influence of the mobile phase's parameters on the retention times and enantioselectivity was evaluated. On the basis of the results obtained, the same protein was studied as a background electrolyte additive in free solution capillary electrophoresis, in order to evaluate if capillary electrophoresis (CE) could be used as a rapid scouting technique for screening the enantioselectivity of novel proteins without immobilisation on a solid support. To investigate if it is possible to directly compare the results obtained by each technique, the CE experiments were planned on the basis of both the findings and ideas originated in liquid chromatography.     

Electron-impact-induced rearrangements of organic ions–II:1 Unimolecular decompositions of some isomeric [C9H10H]+ metastable ions

[C₉H₁₀N]⁺ cations (m/e 132) are generated by electron-impact from structurally distinct compounds within a mass spectrometer. They undergo three metastable fragmentation processes, preceded by isomerisation reactions of the precursor ions. The kinetics and energetics of the unimolecular reactions involved are discussed.