A Raman Spectroscopic and Computational Investigation of Hydrogen Bonding in Phenoxyethanol
Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Session: 2
Room: Exhibit Hall A
Cornell Jones - University of Arkansas at Pine Bluff
Co-Author(s): Leigh A. Hunt, University of Mississippi, Oxford, MS; April E. Hardin, University of Mississippi, Oxford, MS.
Phenoxyethanol is used as a preservative in cosmetic products and as a stabilizer in perfumes and soaps. Exposure to phenoxyethanol has been linked to reactions ranging from eczema to severe, life-threatening allergic reactions. Infant oral exposure to phenoxyethanol can acutely affect the nervous system function. In cosmetic products, Phenoxyethanol is used to limit bacterial growth. Phenoxyethanol has global approval for use in all cosmetic products in concentrations up to 1% though it is often used in even lower amounts, such as when combined with other ingredients like ethylhexylglycerin. Phenoxyethanol has become the new skincare ingredient to be criticized by various retail and natural marketing cosmetic media. Much like parabens, phenoxyethanol being a problem in cosmetics is based on research that is not geared towards skincare. The negative research about phenoxyethanol is not about the cosmetics-grade version. This study was conducted on the approach of investigating the intermolecular interactions and hydrogen bonding of Phenoxyethanol in arranged solvents, to further research into this emerging cosmetic additive. Spectra were obtained using a LabRAM HR Evolution Raman Spectrometer with a 600gr/mm grating. Pure Phenoxyethanol was studied using a 532 nm diode laser. Phenoxyethanol solutions were studied using a 633 nm diode laser. Optimized structures and simulated. Raman spectra were obtained using the Gaussian 09 Software package with the B3LYP density functional and the 6-311G(d,p) triple-Z basis set. This approach to the collection of Simulated Raman Spectra shows reasonable agreement to previously published works. Phenoxyethanol displayed higher peak resolution in Carbolic Acid compared to the other solvents. The OH peak is broadened and decreased in intensity in experimental spectra due to the great number of hydrogen bonds in a real solution. The benzene breathing mode at ~1000 cm-1 can be observed in all experimental spectra. Run calculations using diffuse functions to better define the hydrogen bonding on Phenoxyethanol. Run additional calculations with greater numbers of solvent molecules to better model vibrational mode shifting in solution. Test a sample of commercial fragrance. Perform temperature control study of Phenoxyethanol in Carbolic Acid. Obtain spectra and perform calculations on Phenoxyethanol and ethylhexylglycerin.
Funder Acknowledgement(s): This work is supported by the National Science Foundation under Grant No. NSF CHE- 1757888
Faculty Advisor: Grant Wangila, wangilag@uapb.edu
Role: I conducted all the work behind this research product with the advisement of Leigh A. Hunt and April E. Hardin, such as running samples using the Raman Spectrometer, testing theoretical calculations on Gaussian 09 software, and comparing the data and drawing conclusions from the experiment conducted.