pubmed-article:12779047 | pubmed:abstractText | Physico-chemical properties of compounds prepared from 2,2'-bipyridine, 1-alkyl-2-(2-pyridyl)pyridinium bromides, were investigated by DC polarography and by GC-MS. Their ionization potentials were calculated. Additionally, the formation of associates with bromothymol blue and methyl orange during the spectrophotometric determination was measured. It was determined that 1-alkyl-2-(2-pyridyl)pyridinium ions are reduced by 2 one-electron steps in a DC polarography system. The reduction potentials are not related to the ionization potential values calculated for the substances investigated. The carcinogenic potential (tg alpha) of the parent compound 2,2'-bipyridine and of a series of 1-alkyl derivatives was very low indicating that the compounds are not carcinogenic. The MS fragmentation patterns indicate the low stability of the 1-alkyl substituents. It was shown that 2,2'-bipyridine is either fragmented to two pyridine ions or the--N=CH--fragments are removed. Additionally, spectrophotometric determinations of colored associates of 1-alkyl-2-(2-pyridyl)pyridinium bromides with bromothymol blue and methyl orange were investigated and the optimal condiditions for these determinations are reported. | lld:pubmed |