Effect of perchlorate on the fluorescence of protonated 2,2'-bipyridine.

Interaction between the monocation of an aromatic amine, 2,2'-bipyridine and perchlorate anion was studied. The protonation process by perchloric acid has been followed by the changes in the UV absorption spectra and in the fluorescence emission. Addition of lithium perchlorate with increasing amount results in a significant increase in the fluorescence of 2,2'-bipyridine (the bipyridyl cation). This increase in fluorescence indicates that the rotation in the protonated monocation is hindered in the presence of perchlorate. We assume that this hindrance is due to the formation of the BpH+.ClO4- ion-pair.

Investigation of catalytic reaction with spectrofluorimetric method.

Numerous derivatives of nicotinic acid hydrazids are suitable for sensitive fluorescence determination of metal ions. The reaction proceeds upon ultraviolet illumination in the presence of an oxidizing agent and catalyst forming a fluorescent product. Therefore, the catalyst metal ion can be quantitatively determined by fluorescence methods. We have studied the reaction of nicotinic acid (di-pyridin-2-yl-methylene)-hydrazide (NADPMH), catalyzed by Mn(II)ion, and determined the optimal parameters of metal ion method.