Spectral-luminescent properties and molecular orbital treatment of some mono- and difluoroquinolones

Anna V. Polishchuk, Emilya T. Karaseva, Tatyna B. Emelina, Oana Cramariuc, Vladimir E. Karasev

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    2 Citations (Scopus)


    Electronic absorption and luminescent spectra of nonfluorinated nalidixic (nlqH) and pipemidic acid (pifqH), monofluoroquinolones – norfloxacin (nfqH) and pefloxacin (pfqH) as well as of their difluorinated analogs 1-ethyl-6,8- difluoro-1,4-dihydro-7-(1-(4-methylpiperazinyl) – 4-oxo-3- quinolinecarboxylic (mdfqH) acid and 1-ethyl-6,8-difluoro- 1,4-dihydro-7-(1-piperazinyl) – 4-oxo-3-quinolinecarboxylic acid (dfqH) - were investigated. Quantum yields, lifetimes of excited states and rate constants of radiative and nonradiative transitions of the compounds were measured. The Mulliken charges of atoms from these compounds were calculated by quantum-chemical complex GAMESS. Differences in the electronic structures of these compounds and their spectral-luminescent characteristics were compared with the data of the phototoxicity degree of fluoroquinolones. Analysis of the Mulliken charges of the difluoroquinolones points to the changes of the redistribution of the electron density along π-conjugated system, and on the oxygen atoms of the carbonyl and carboxyl groups. The analysis of the molecular orbitals involved in the electronic transitions of the compounds revealed that both defluorination and piperazine photolysis are photodecomposition mechanisms which may take place in the excited states of these compounds. The relationship between the location order of the π-π* excited levels of the FQs and the degree of their phototoxicity has been determined.
    Translated title of the contributionSpectral-luminescent properties and molecular orbital treatment of some mono- and difluoroquinolones
    Original languageEnglish
    Pages (from-to)1293-1300
    JournalJournal of Fluorescence
    Issue number3
    Publication statusPublished - 2011
    Publication typeA1 Journal article-refereed

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