Synthesis studies and application of porphyrinsand boron dipyrromethenes appended with energy donor groups

by E. K. PraseethaPh.D

Carbazole substituted boron dipyrromethene dyes

by E. K. Praseetha and Iti Gupt

meso-Carbazole substituted boron dipyrromethenes as a potential dye candidate for DSSC

by E. Kesavana Praseetha and Iti Gupt

Bridged BODIPYs: synthesis and computaional studeis

by E. Kesavana Praseetha and Iti Gupt

Bridged Bis-BODIPYs: synthesis & studies

by Iti Gupta and E. K. Praseeth

Difunctionalized N-Confused porphyrins: synthesis, fluorescence, and electrochemical studies

Seven di-substituted N-confused porphyrins (NCPs) 9–15 bearing two aryl functional groups (cis-A2B2 type) were synthesized in 4–7 % yields via [3+1] approach. The corresponding five 5,10-diaryl-substituted symmetrical tripyrranes 1–5 were prepared and condensed with 2,4-bis(hydroxypentaflurophenyl)pyrrole 6. Two outer N-methyl type A2B2 NCPs 14 and 15 were also prepared via a similar approach using a new key precursor 8. All the porphyrins 9–15 were characterized by high-resolution mass spectrometry, NMR, infrared spectroscopy, UV–visible spectroscopy, fluorescence spectroscopy, and cyclic voltammetry. Fluorescence studies of 9–15 showed blue-shifted emission maxima and lower Stokes shifts values when compared with N-confused tetraphenylporphyrin (NCTPP). Electrochemical studies indicated easier oxidation of N-methyl NCPs 14 and 15 when compared with remaining NCPs 9–13.by Sudipta Das, Naresh Balsukuri, E. Kesavan Praseetha and Iti Gupt

Water soluble thioglycosylated BODIPYs for mitochondria targeted cytotoxicity

The facile synthesis of water-soluble mitochondria targeting thioglycosylated BODIPYs is reported. Thioglycosylated BODIPYs were synthesized in 25�26% yields via thioglycosylated dipyrromethanes in four steps. The dipyrromethanes and thioglycosylated BODIPYs were characterized by various techniques including HRMS, NMR spectroscopy and X-ray crystallography. In-vitro cellular investigations in skin keratinocyte (HaCaT) and cervical (HeLa) cancer cells revealed significant cytotoxicities with IC50 values between 23.83 to 48.61??M. The flow cytometry experiments revealed significant cellular uptake of thioglycosylated BODIPYs into HaCaT cells and thioglucosyl substituted BODIPY (9) showed higher cellular uptake and ROS generation than the rest of the molecules. The highlight of this study is the mitochondrial targeting by the neutral BODIPYs, as judged by the colocalization experiments using confocal microscopy.by Praseetha E.Kesavan, Vijayalakshmi Pandey, Md Kausar Raza, Shigeki Mori and Iti Gupt

Bridged Bis-BODIPYs: synthesis, structures and properties

A series of bis-BODIPYs 1-6 bridged via thiophene, furan, N-alkylcarbazole, triphenyl amine, para- and meta-phenylene groups have been synthesized and characterized by various spectroscopic techniques. The change in spectroscopic properties of bis-BODIPYs upon varying the size of spacer was studied. X-ray crystal structures of three bis-BODIPYs containing triphenylamine, para- and meta-phenylene bridges were solved. Intermolecular C(H)----andstacking interactions were observed in solid state structures of three bis-BODIPYs. The dihedral angles between the spacer unit and two borondipyrrin units were lower in all three compounds as compared to their corresponding monomers. This suggests increased interactions between the two boron-dipyrrin units in molecules which in turn reflected in the anodic shifts in their reduction potentials. DFT studies indicated effective electronic interactions between spacers and two boron dipyrrins units in all the bis-BODIPYs. The calculated HOMO-LUMO gap was found to be lower for bis-BODIPY having bulky carbazole spacer and higher for bis-BODIPY having smaller furan spacer. The change in spacer size clearly affected the spectroscopic properties of the bis-BODIPYs and red shifted absorption and emission maxima were observed for bis-BODIPYs with furan and thiophene spacers as compared to bis-BODIPYs with phenylene or bulky aromatic spacers.by Praseetha E. Kesavan, Sudipta Das, Mohsin Y. Lone, Prakash C. Jha, Shigeki Moric and Iti Gupt