Abstract:
Compounds 1 and 2 were synthesised using multi-component one-pot condensation reaction
between 2-hydroxynaphthaldehyde, urea/thiourea and ethyl/methyl acetoacetate, catalysed with
Zn(ClO4)
2·6H2O in methanol. Compounds 1 and 2 were purified and characterised using 1H and 13C
NMR, mass and CHN analyses. Organic nanoparticles (ONPs) were developed from compounds 1
and 2 using reprecipitation technique. Size and morphology of nano-aggregates N1 and N2 were
analysed using DLS and transmission electron microscope techniques. Nano-aggregates of 1
and 2 were further subjected to chemosensory applications in aqueous medium. Efficient nanoaggregates
of compound 1 have shown excellent detection limit of 0.04 nM for chloride in aqueous
medium. None of the other anions tested caused any interference in the detection of chloride.
However, nano-aggregates of compound N2 were not active for any particular ion in aqueous
medium. The difference in the recognition properties can be due to the difference in the size and
electronegativity of oxygen and sulfur moieties attached on 1 and 2, respectively. The sensor was
used to determine the chloride content in tap water. Results were validated using existing methods
and the performance of the N1 was found to be in a satisfactory error range.
