Structural effects on the electrochemisty and charge distribution of mono-, di-, and tri-cyanovinyl aromatic compounds

Abstract

The effect on electrochemical behaviour and electronic charge distribution was examined for a series of 12 vinyl aromatic compounds having the following structural variations : (a) number of cyano-groups attached to the vinyl double bond, (b) substitution para to the vinyl group, and (c) separation between para-substituent and the vinyl group. The radical anion formed in the first one-electron reduction step can either accept a second electron or undergo an irreversible dimerization. Oxidation waves were seen only with those compounds having an amino nitrogen atom para to the vinyl group. Trends in half-wave potentials caused by variation in structure are correlated by means of the Hammett-Zuman and molecular orbital approaches. Due to the strong electron-withdrawing power of the cyano-substituted vinyl group, considerable intramolecular donor-acceptor interaction occurs between the ends of the molecules. This is seen in the measured molecular dipole moments and reflected in the nitrile stretching frequencies and proton chemical shifts. Finally, the efficiences for generation of charge carriers in the compounds as measured by xerographic discharge are related to their solution reduction potentials.THE characterization of the series of mono-, di-, and tricyanovinyl aromatic compounds (1)-(XII) receives its impetus from the possibilities for electrophotographic application shown by members of this class of com-pounds1 Recent reports from these laboratories describe changes of orders of magnitude in charge carrierx -CN

Structural Effects Determining the Reductive Electron Transfer Chemistry of 2.5-Disubstituted Furans — One and “Two-electron” Transfer Behaviour Investigated by Cyclic Voltammetry and UV/VIS/NIR-Spectroelectrochemistry

“…(d) Prospects as organic photoconductive materials: Some of the compounds have potential in the application as photoconductive materials. Two of the reasons are given in the following: J. E. Kuder et ai indicated that in mono-, di-and tri-cyanovinyl substituted aromatic compounds there exists a correlation in the generation of charge carriers and their reduction potential in solution [37]. The same should also apply to the compounds studied in this work.…”

Solid-state organization of n-type carbazole-based semiconductors for organic thin-film transistors

“…(1,2,2-tricyanovinyl)-9H-carbazole 16,17 (2) and 9-butyl-3-(1,2,2tricyanovinyl)-9H-carbazole 16 (3) were prepared as described in the literature. 9-octyl-3-(1,2,2-tricyanovinyl)-9H-carbazole 49-Octyl-9H-carbazole (481 mg, 1.72 mmol) was dissolved in 10 mL of anhydrous DMF under a nitrogen atmosphere.…”

The photophysical properties of a julolidene-based molecular rotor

“…To date, it has not been possible to adequately discriminate between viscosity and polarity effects for 1, although several reports have focused on how the fluorescence properties depend on the applied pressure. 15 The ground state molecule is surprisingly polar, having a dipole moment of 9.4 D, 16 and the N-donor is likely to hydrogen bond to protic solvents.…”