B. R. Jali, J. Baruah
Nov 1, 2014
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0
Influential Citations
15
Citations
Journal
Dyes and Pigments
Abstract
Abstract Three positional isomers namely 4-(hydroxyphenylthio)naphthalene-1,2-dione having the para-, ortho- or meta-hydroxyphenylthio units were synthesized and characterized. The isomer having para-hydroxyphenylthio unit showed dual-fluorescence in certain solvents such as dimethylacetamide, which could be tuned to single fluorescence emission by adding methanol. Fluorescence emission intensities of these isomers increased by 5–6-fold on addition of aluminium ions, with an exception being the isomer having the ortho-hydroxyphenylthio unit, which showed a two tier change of fluorescence intensity with an initial enhancement followed by a decrease. The fluorescence lifetime decay study in the presence and absence of aluminium ions suggests that at low concentration of aluminium ions exciplex formation took place. Crystal structures of these isomers as well as methanol and dimethylacetamide solvates of para-hydroxyphenylthio unit containing isomer were determined. Self-assembling patterns have provided information on the nature of hydrogen bonds contributing to proton transfer.