Azulene Moiety as Electron Reservoir in Positively Charged Systems; A Short Survey
Alexandru C. Razus
Abstract
The non-alternant aromatic azulene, an isomer of alternant naphthalene, differs from the latter in peculiar properties. The large polarization of the π-electron system over the seven and five rings gives to azulene electrophile property a pronounced tendency to donate electrons to an acceptor, substituted at azulene 1 position. This paper presents cases in which azulene transfers electrons to a suitable acceptor as methylium ions, positive charged heteroaromatics and examples of neutral molecules that can accept electrons. The proposed product synthesis was outlined and the expected electron transfer was highlighted by analyzing the NMR, UV-Vis spectra and the pKR+ values.
Topics & Concepts
AzuleneMoietyElectronElectron acceptorChemistryAcceptorElectrophileIonNaphthalenePhotochemistryMoleculeAromaticityStereochemistryOrganic chemistryPhysicsCatalysisQuantum mechanicsCondensed matter physicsSynthesis and Properties of Aromatic CompoundsPhotochemistry and Electron Transfer StudiesPhotochromic and Fluorescence Chemistry