Synthesis, single-crystal characterization, antimicrobial activity and remarkable in vitro DNA interaction of hydrogen-bonded proton-transfer complex of 1,10-phenanthroline with 2,4,6-trinitrophenol

A new charge transfer complex as a result of interaction between 1,10-phenanthroline (donor) with 2,4,6-trinitrophenol (picric acid), acceptor, was synthesized and characterized by FTIR, 1H NMR, 13C NMR, mass spectroscopy, single-crystal X-ray diffraction and elemental analysis. The single crystal structure indicates that the cation and anion are joined together by strong N+H⋯O− type hydrogen bonds. This has been attributed to the formation of 1:1 CT complex via hydrogen bonding interaction. The binding of CT complex with in vitro calf thymus DNA was investigated by the fluorescence spectroscopy. To determine the DNA binding ability of the compound, fluorescence intensity data were analyzed by the Stern–Volmer equation and remarkable DNA interaction with CT complex is found. The CT complex was also screened for its antimicrobial activity. The CT complex exhibited inhibitory results against E. coli and Pseudomonas arenginosa, and the marked enhancement in the potency as antifungal agent.

Fluorescence emission spectra of CT complex in the absence (—) and presence of increasing amount of DNA from top second spectra to bottom.Figure optionsDownload as PowerPoint slideHighlights
► In this article, we report the formation of newly hydrogen-bonded charge transfer complex.
► We characterize hydrogen-bonded charge transfer complex.
► The crystal structure CT complex determined by single-crystal X-ray diffraction.
► We examine the DNA-binding studies of CT complex.
► The CT complex is also screened for its antifungal and antibacterial activity.