Search

Synthesis of four new arene ruthenium(II) complexes [(η 6 -C 10 H 14 )RuCl(MFPdpm)] ( 1 ); [(η 6 -C 12 H 18 )Ru-Cl(MFPdpm)] ( 2 ); [(η 6 -C 10 H 14 )RuCl(PFPdpm)] ( 3 ) and [(η 6 -C 12 H 18 )RuCl(PFPdpm)] ( 4 ) containing dipyrrin ligands 5-(4-fluoro)phenyldipyrromethene (MFPdpm) and 5-(penta-fluoro)phenyldipyrromethene (PFPdpm) have been described. The ligands and complexes have been thoroughly characterized by elemental analyses, spectroscopic studies (ESI-MS, IR, 1 H, 13 C NMR, UV–Vis) and structure of the representative complex 4 determined by X-ray single crystal analyses. DNA binding activities of 1 – 4 have been investigated by UV–Vis and fluorescence spectroscopy and their binding through the minor groove of DNA has been established by molecular docking studies. The complexes 1 – 4 exhibit significant cytotoxicity toward human lung cancer cell line (A549). Cytotoxicity, morphological changes, and apoptosis studies have been evaluated through MTT assay, Hoechst 33342/PI staining, and cell cycle analysis by fluorescence activated cell sorting (FACS). In vitro antitumor activity and cytotoxicity of the complexes lie in the order 4 > 3 > 2 > 1 . [ABSTRACT FROM AUTHOR]

Three novel chalcone based asymmetrical D–A–D′–A'chromophores (C1 – C3) have been designed and synthesized with intent to achieve dual state emission. It has been contemplated that introducing both flexible and rigid moieties to the D–A core will suffice for the emission in solution as well as solid state. In this regard flexible piperazine unit has been introduced along with rigid polyaromatic hydrocarbons anthracene, C1 ; pyrene, C2 and phenothiazine, C3 to afford an asymmetric D–A construct. The compounds have been thoroughly characterized by spectroscopic studies (1H, 13C, ESI–MS, UV/Vis and fluorescence). The compounds C1–C3 display varying degree of dual state emission as envisaged by photo-physical investigation in solution, aggregated and solid state along with quantum yield assessment. Notably the aggregation has been instigated in these compounds by taking advantage of relative hydrophilicity/hydrophobicity of different solvent systems. The revered intramolecular charge transfer (ICT) imparts substantial solvatochromism to these D−A constructs. The prudence of incorporation of heteroatomic phenothiazine unit to the designed chromophores is reflected in superior dual state emission and solvatochromism of C3. In addition, these compounds revealed remarkable acid–induced fluorescence quenching effect in solution and solid state as the emission of C1–C3 could be quenched by trifluoroacetic acid (TFA) significantly. Image 1 [ABSTRACT FROM AUTHOR]