2-(2-Hydroxyphenyl)benzoxazole (HPBO) exhibits enhanced florescence and specificity for Li+ compared to Na+ and K+, in an alkaline medium. The selectivity was observed in several organic solvents in the presence of bases such as pyridine, triethylamine and trimethylamine. HPBO-Li+ complex formation results in an intense blue emission readily observed by the naked eye under UV light. Spectroscopic titrations suggest that the structure of the complex is one in which two HPBO anionic ligands coordinate to one Li+, witha second Li+ as a counterion.
ASJC Scopus subject areas
- Materials Chemistry