Proton Induced Modulation of ICT and PET Processes in an Imidazo-phenanthroline Based BODIPY Fluorophores.

BODIPY fluorophores linked with an imidazo-phenanthroline donor at α and β positions have been synthesized. Intriguing intramolecular charge transfer phenomenon is observed in both the dyes which has been extensively investigated using UV-vis absorption, steady-state and time-resolved fluorescence measurements. H-bonding and intrinsic polarity of the solvents has modulated the absorption and emission bands of these fluorophores strongly causing significant increase in the Stokes shifts.

Supramolecularly Assisted Modulation of Optical Properties of BODIPY-Benzimidazole Conjugates.

Supramolecular host-guest interaction of neutral and cationic (protonated) forms of two boron-dipyromethane (BODIPY)-benzimidazole (mono- and di-benzimidazole) conjugate dyes with the macrocyclic host cucurbit[7]uril (CB7) has been investigated using photophysical and density functional theory studies. Expectedly, cationic forms of the dyes show exceptionally stronger binding than that of the neutral forms with CB7, which can be ascribed to the strong ion-dipole interaction between the positive charge of the dye and the highly polarizable carbonyl portals of the host. The formation of dye-host inclusion complexes is supported by the significant changes in the photophysical properties and longer rotational relaxation times of the dye in the presence of CB7.