The reported results in this paper confirm the previous statement on the limited validity of the EE rule for the molecular ion generation when ESI method was used in mass spectrometer. Thus, the ratio [M].+/[M+1]+ increases with the molecule oxidizability until the absence of the protonated form; therefore, in several cases the base peak fragment is not always an EE fragment. In addition to the basic fragmentation of the compounds with one selenium

Colored Benzo- and dibenzo-crown ethers with (azulene-1-yl) azo chromophore(s) at benzo ring(s) were synthesized in good yields starting from the amines of the benzo- and dibenzo-crown ethers which were diazotized and coupled with azulenes. The obtained crown ethers were characterized and several properties of the generated new dyes were investigated (electronic and NMR-spectra, as well as pKa values, the lipophilicity and the coordination with metal

This work was devoted to the synthesis and characterization of newindolizine derivatives. Particular attention was paid to electrochemical investigations by cyclic voltammetry and differential pulse voltammetry. The redox processes for each compound were established, analyzed and assigned to the particular functional groups at which they occur. This assignment was based on detailed comparisons between the electrochemical behaviour of the compounds,

The fragmentation of unsubstituted and substituted 1-phenylselanyl-azulenes, as well as of the corresponding selenoxides and selenones in the electrospray ionization mass spectrometer, was reported and examined. Both their molecular peaks and the fragmentation paths were discussed in function of the azulene substituents and of the selenium oxidation states.

This work is devoted to the synthesis and characterization of new pyrrolo[1,2-c]pyrimidine derivatives. The electrochemical investigations have been done by cyclic voltammetry and differential pulse voltammetry. The redox processes for each compound were established, analyzed and an assessment was proposed to the particular functional groups at which they take place. It was based on comparison between the electrochemical behaviour of the compounds,

This work is devoted to the synthesis and characterization of new pyrrolo[1,2-c]pyrimidine derivatives. The electrochemical investigations have been done by cyclic voltammetry and differential pulse voltammetry. The redox processes for each compound were established, analyzed and an assessment was proposed to the particular functional groups at which they take place. It was based on comparison between the electrochemical behaviour of the compounds,

New 4-azulen-1-yl-pyrylium salts 2- and 6-substituted with either naphthyls or naphthyl and phenyl groups were obtained and characterized. The dyes were obtained by the reaction of the corresponding 4-pyrones with azulenes in the presence of POCl3. The starting pyrones were prepared by the cyclization of either 1,5-diaryl-1,3,5-triketones or 1-hydroxy-1,5-diaryl-pent-1-en-4-yn-3-ones. The possibility that the obtained pyrylium salts to interact with

Indolizine derivatives have been used in medicine and pharmacology due to their biological activity and have also found application in modern sensors manufacturing technologies due to their capacity to form surface films. This work is devoted to the electrochemical study of ethyl 3-(4-bromobenzoyl) indolizine-1-carboxylate, ethyl 3-(4-chlorobenzoyl) indolizine-1-carboxylate and ethyl 3-(4-methylbenzoyl) indolizine-1-carboxylate by cyclic voltammetry

Several azo derivatives containing both azulene and benzocrown ethers were investigated using mass spectroscopy-ESI method. The compounds form stable protonated molecular ions in positive method and deprotonated anions in negative method. The parent peaks were broken at higher energies and some general rules for their scission were evidenced.