Spectroscopic study of coordination of Cu2+ with liquid crystal HBDBA: An investigation at ultra trace level

The present work describes the synthesis and characterization of a copper complex with a liquid crystal compound called N-(o-hydroxybenzylidene)-N'-(4-n-alkoxybenzylidene) azines (HBDBA). The FTIR/ Raman spectroscopy and DFT calculations were employed to confirm the coordination of Cu2+ ion with HBDBA. On complex formation several changes in the Raman and FTIR spectra were observed. The linewidth and peak position of few Raman/ IR bands changed and few new bands in the Raman and IR spectra appeared. The experimentally observed bands of HBDBA molecule and its Cu2+- complex are assigned with the help of DFT. In the next part a concentration-dependent study has been done to detect ultra-trace amount (∼10-8 M) of Cu2+ ion binding with HBDBA using Raman and fluorescence spectroscopy. The result suggests that HBDBA can be used to detect Cu2+ ions in trace amount.