Date of Award
Assefa, Dr. Zerihun
This work entails the research on lanthanide metalloporphyrins for their potential use as chemical sensors for benzene and acetonitrile. This research is of importance due to the health implications that benzene and acetonitrile cause; benzene is a known carcinogen and acetonitrile is a known lung irritant. The use of UV-Vis spectroscopy, Fluorescence spectroscopy, Gaussian DFT, and X-ray diffraction crystallography were used in the characterization and analysis of the lanthanide porphyrin complexes. Europium, terbium, dysprosium, cerium, and gadolinium were the lanthanides used in conjunction with 5,10,15,20-tetraphenylporphyrin, TPP and 5,10,15,20 tetrakissulfonato porphyrin, TBSP. Based on the luminescence spectroscopy and UV-Vis spectroscopy data, an aqueous sensor for acetonitrile and benzene was shown to be promising. Among the compounds studied, EuTPP and DyTPP complexes exposed to sodium hydroxide showed promising results for sensing acetonitrile due to significant narrowing of the soret band and the decrease of Q bands in the UV-Vis spectra, along with the blue shifting of luminescence emission spectra. On the other hand, the CeTPP and EuTPP solutions show promise as benzene sensors due to the blue shifting of emission luminescence and variation in intensity. Based on the lanthanide TBSP complexes, TbTBSP was shown to be a promising sensor for acetonitrile due to the narrow soret band, decreased Q bands, and blue shifted emission spectra. EuTBSP, DyTBSP, and TbTBSP were shown to be promising for benzene sensors. Benzene stabilized the TBSP at a higher energy state, S2, to facilitate the energy transfer to the lanthanide ions.
Crawford, Jr Carlos, "Spectroscopic Study Of The Use Of Lanthanide Metalloporphyrins As Sensors For Benzene And Acetonitrile Detection In Aqueous Studies" (2013). Theses. 304.