Wirt/Gast‐Chemie organischer Oniumverbindungen – Clathrate, kristalline Komplexe und molekulare Einschlußverbindungen in wäßriger Lösung

Heteroaromatic Tripoles. 2,6-Bis(hetarenio)pyrimidin-4-olates: Hybrids between Hetarenium Salts and Cross-Conjugated Mesomeric Betaines

“…The π−π* absorption, which is associated with an intramolecular charge transfer, shifts to shorter wavelengths with increasing solvent polarity because the ground state is better stabilized by polar rather than by nonpolar solvents. However, the halide gegenions of multiply charged systems are known to be heavily solvated, , and moreover, the formation of clathrates by dicationic onium compounds is well-documented . In accordance with these findings, the elemental analyses of 8 − 10 indicate the presence of nonstoichiometric amounts of water of hydration.…”

A Novel Type of Cationic Host Molecules with π‐Acceptor Properties

“…It is then unnecessary for the host cavity to be completely enveloped and the charge centers to lie on the periphery. [2,31 As reported in the preceding communications, J . F. Stoddart et al have synthesized a tetracation of type 1 with two p-xylylene bridges by the method described here and have characterized host-guest compounds containing dimethoxybenzene~.…”