Showing 1 - 9 of 9 Items
Photoacidic properties of 8-amino-2-naphthol in imidazolium salts Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2023-01-01
Creator: Rachel E Nealon
Access: Access restricted to the Bowdoin Community
Developing methods of transient absorption spectroscopy for the study of triplet state photoacids Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2023-01-01
Creator: Jack R Callahan
Access: Access restricted to the Bowdoin Community
Investigating the Effects of Mixed Solvents on the Excited State Proton Transfer Mechanisms of 8-Amino-2-naphthol This record is embargoed.
- Embargo End Date: 2027-05-19
Date: 2022-01-01
Creator: Alexander Avrom Kreines
Access: Embargoed
Investigating the photoacidic properties of 8-benzylideneamino-2-naphthol This record is embargoed.
- Embargo End Date: 2027-05-19
Date: 2022-01-01
Creator: Oliver M. Nix
Access: Embargoed
Photochemistry of Cyano-Substituted 8-Amino-2-Naphthol This record is embargoed.
- Embargo End Date: 2026-05-20
Date: 2021-01-01
Creator: Jialin Xie
Access: Embargoed
Solvent Effect on Excited State Proton Transfer Mechanism of 8-Amino-2-Naphthol
Date: 2021-01-01
Creator: Gabrielle Vandendries
Access: Open access
- Photoacids, compounds that undergo excited state proton transfer (ESPT), have been utilized in different solar energy and lithographic applications.1, 2 The addition of functional groups and solvent can both change the ESPT mechanism of photoacids. In this study, the effect of solvent on the ESPT mechanism was explored using a model diprotic photoacid, 8-amino-2-naphthol (8N2OH). The photochemistry of 8N2OH in water and common nonaqueous solvents, acetonitrile, tetrahydrofuran (THF), and methanol, were studied using UV/Vis absorption, steady-state emission, and time-correlated single photon counting (TCPSC) emission spectroscopy. The results were analyzed using the Kamlet-Taft parameters. It was found that the ESPT mechanism of the cation in water is different from the mechanism in acetonitrile and THF. In water the excited cation forms the zwitterion, i.e. the OH site undergoes ESPT, while in acetonitrile and THF, the excited cation forms the neutral species, i.e. the NH3+ site undergoes ESPT. No ESPT was observed for 8N2OH in methanol. The effect of solvent mixtures on photoacidity was also investigated using acetonitrile and water mixtures. The solvent effects were more subtle; the time-resolved emission measurements showed the greatest stabilization of the excited neutral 8N2OH species at 20/80% acetonitrile-water mixtures. Finally, the ability to extend the solvent studies to ionic liquids, 1-ethyl-3-methylimidazolium (Im) trifluromethanesulfonate (OTF), was demonstrated. The combined studies reveal that solvent plays a large role in determining the ESPT mechanism and stabilization of 8N2OH.
Benchmarking Ab Initio Computational Methods for the Quantitative Prediction of Sunlight-Driven Pollutant Degradation in Aquatic Environments
Date: 2016-05-01
Creator: Kasidet Trerayapiwat
Access: Open access
- Understanding the changes in molecular electronic structure following the absorption of light is a fundamental challenge for the goal of predicting photochemical rates and mechanisms. Proposed here is a systematic benchmarking method to evaluate accuracy of a model to quantitatively predict photo-degradation of small organic molecules in aquatic environments. An overview of underlying com- putational theories relevant to understanding sunlight-driven electronic processes in organic pollutants is presented. To evaluate the optimum size of solvent sphere, molecular Dynamics and Time Dependent Density Functional Theory (MD-TD-DFT) calculations of an aniline molecule in di↵erent numbers of water molecules using CAM-B3LYP functional yielded excited state energy and oscillator strength values, which were compared with data from experimental absorption spectra. For the first time, a statistical method of comparing experimental and theoretical data is proposed. Underlying Gaussian functions of absorption spectra were deconvoluted and integrated to calculate experimental oscillator strengths. A Matlab code written by Soren Eustis was utilized to decluster MD-TD-DFT results. The model with 256 water molecules was decided to give the most accurate results with optimized com- putational cost and accuracy. MD-TD-DFT calculations were then performed on aniline, 3-F-aniline, 4-F-aniline, 3-Cl-aniline, 4-MeOacetophenone, and (1,3)-dimethoxybenzophenone with CAM-B3LYP, PBE0, M06-2X, LCBLYP, and BP86 functionals. BP86 functional was determined to be the best functional. Github repository: https://github.com/eustislab/MD_Scripts
The Photodegradation of Endocrine Disrupting Compounds in Aqueous Solutions Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Peyton C Morss
Access: Access restricted to the Bowdoin Community
Application of the Landau-Zener Model and Fermi's Golden Rule to Estimate Triplet Quantum Yield for Organic Molecules Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Nathan D Ricke
Access: Access restricted to the Bowdoin Community