Higashi, Tomohiro published the artcileDiphenyl Viologen on an HOPG Electrode Surface: Less Sharp Redox Wave than Dibenzyl Viologen, Safety of 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, the publication is Langmuir (2013), 29(36), 11516-11524, database is CAplus and MEDLINE.
Redox behavior of di-Ph viologen (dPhV) on a basal plane of a highly oriented pyrolytic graphite (HOPG) electrode was described using the results of voltammetric and electroreflectance measurements. Its characteristics were compared to those of dibenzyl viologen (dBV), which undergoes the 1st-order faradaic phase transition. Unlike dBV, dPhV-dication (dPhV2+) was found to take a strongly adsorbed state on an HOPG surface. This is due to much stronger Ï-Ï interaction between Ph rings of dPhV2+ and HOPG surface than between benzyl groups of dBV2+ and the surface. The participation of this strongly adsorbed dPhV2+ in the redox process can be avoided by (1) a shorter than â? min time period elapsing from touching a freshly cleaved HOPG surface to dPhV solution until the start of potential scan, (2) complete equilibration at the electrode potentials at which superficial dPhV mols. are fully reduced, or (3) multiple cyclic potential scanning to repeat oxidation-reduction of adsorbed species. Even in such conditions, although voltammograms of thin-layer electrochem. for the surface-confined dPhVâ?/dPhV2+ couple were obtained with peak widths being as narrow as those of dBV, it is not the 1st-order phase transition. The participation of strongly adsorbed dPhV2+ mols. results in another new voltammetric feature with a broader peak. The film formed by strongly adsorbed dPhV2+ was hydrophilic, whereas dBV2+ does not form such a film but only a gas-like layer. Measurements using XPS confirmed that the film consists of dPhV2+ with coexistent H2O. These results reveal a typical case that delicate interaction balance among V2+, Vâ?, and electrode surface determines whether the two-dimensional 1st-order transition takes place or not.
Langmuir published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C22H18Cl2N2, Safety of 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride.
Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem