Invited feature articleSynthesis of new triazole based imidazo[1,2-a]pyrazine-benzimidazole conjugates: H-bonding assisted FRET efficient ratiometric detection of pyrophosphate

- A series of triazole based imidazo[1,2-a]pyrazine-benzimidazole analogues have been synthesized.
- Compounds were synthesized through click and Suzuki reactions.
- Quantum yields of the synthesized compounds were determined.
- FRET efficiency of the molecule has been used for the ratiometric detection of pyrophosphate.

Triazole tethered imidazo[1,2-a]pyrazine-benzimidazole conjugates 13-38 has been synthesized by click and Suzuki-Miyaura cross coupling reactions at C-8 and C-6 positions, respectively. The research findings clearly predicted that by modification of electronic structure of the receptor, the sensitivity of the recognition process could be modified. Compound 24 with hydroxyphenyl substituent, showed stronger binding to the pyrophosphate than other compounds. Compound 24 has been used as selective probe for ratiometric detection of pyrophosphate amongst the other anions. The binding event of compound 24 toward PPi has been successfully evaluated by absorption and emission spectroscopy as well as NMR titration method. The compound 24 showed H-bonding assisted facilitation of FRET phenomenon in the presence of PPi.

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