Manual of VIKAASA: An application capable of computing and graphing viability kernels for simple viability problems

This manual introduces and provides usage details for an application we have developed called VIKAASA, as well as the library of functions underlying it. VIKAASA runs in GNU Octave or MATLAB®, using the numerical computing and graphing capabilities of those packages to approximate, visualise and test viability kernels for viability problems involving a differential inclusion of two or more dynamic variables, a rectangular constraint set and a single scalar control

Spectroscopic evidence for a new type of bonding between a thioether radical cation and a phenyl group

The oxidation potential of thioethers constrained to be near aromatic rings is lowered, due to an antibonding interaction between the p-type sulfur lone pair with the neighboring phenyl π-system which on removal of an electron becomes a new kind of 3-electron S∴π bonding that reveals itself in the photoelectron spectrum and by an electronic transition involving the orbitals participating in the S∴π bond

Spectroscopic Evidence for Through-Space Arene–Sulfur–Arene Bonding Interaction in <i>m</i>‑Terphenyl Thioether Radical Cations

Electronic absorption spectra and quantum chemical calculations of the radical cations of <i>m</i>-terphenyl <i>tert</i>-butyl thioethers, where the S–<i>t</i>-Bu bond is forced to be perpendicular to the central phenyl ring, show the occurrence of through-space [π···S···π]⁺ bonding interactions which lead to a stabilization of the thioether radical cations. In the corresponding methyl derivatives there is a competition between delocalization of the hole that is centered on a p-AO of the S atom into the π-system of the central phenyl ring or through space into the flanking phenyl groups, which leads to a mixture of planar and perpendicular conformations in the radical cation. Adding a second <i>m</i>-terphenyl <i>tert</i>-butyl thioether moiety does not lead to further delocalization; the spin and charge remain in one of the two halves of the radical cation. These findings have interesting implications with regard to the role of methionines as hopping stations in electron transfer through proteins

Spectroscopic Evidence for a New Type of Bonding between a Thioether Radical Cation and a Phenyl Group

The oxidation potential of thioethers constrained to be near aromatic rings is lowered, due to an antibonding interaction between the p-type sulfur lone pair with the neighboring phenyl π-system which on removal of an electron becomes a new kind of 3-electron S∴π bonding that reveals itself in the photoelectron spectrum and by an electronic transition involving the orbitals participating in the S∴π bond