2-Hydroxyphenyl benzimidazoles and their boron complexes: synthesis, structure, aggregation-induced emission and picric acid sensing

Ramar Arumugam; Prakash Nayak; Bijoy Dey; Ramkumar Kannan; Krishnan Venkatasubbaiah; Vadapalli Chandrasekhar

doi:10.1039/d3dt01199b

2-Hydroxyphenyl benzimidazoles and their boron complexes: synthesis, structure, aggregation-induced emission and picric acid sensing

Dalton Trans. 2023 Jun 13;52(23):7926-7935. doi: 10.1039/d3dt01199b.

Authors

Ramar Arumugam¹, Prakash Nayak², Bijoy Dey¹, Ramkumar Kannan¹, Krishnan Venkatasubbaiah², Vadapalli Chandrasekhar^{1

3}

Affiliations

¹ Tata Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad- 500 046, Telangana, India. vc@iitk.ac.in.
² School of Chemical Sciences, National Institute of Science Education and Research (NISER), Bhubaneswar-752050, Orissa, India. krishv@niser.ac.in.
³ Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur- 208 016, Uttar Pradesh, India.

PMID: 37219089
DOI: 10.1039/d3dt01199b

Abstract

A series of differently substituted 2-(2-hydroxyphenyl) benzimidazoles were synthesized by a coupling reaction involving aryl dibromides and 2-hydroxyphenyl benzimidazole. These ligands react with BF₃·Et₂O to yield the corresponding boron complexes. The photophysical properties of the ligands (L1-L6) and the boron complexes (1-6) were studied in the solution state. Among these, the ligands L1-L4 and L6 displayed aggregation-induced emission (AIE) behavior upon the addition of water in THF resulting in a sizable enhancement of fluorescence intensity. Additionally, compound 5 was found to detect picric acid with a detection limit of 8.33 × 10^-7 M.