Investigation of Substituent Effects on the UV-vis Spectra of Curcuminoids and Validation of TD-DFT Methods for their Prediction
Abstract
An array of curcuminoids - analogues of the turmeric extract, curcumin - have been spectroscopically analyzed to compare absorption shifts caused by changes to substituent variations on the terminal phenyl rings. A Hammett-type analysis was conducted in hopes of providing a qualitatively predictive approach for targeting the synthesis of new curcuminoids that absorb at specific wavelengths. In conjunction with this, the time-dependent density functional theory (TD-DFT) approach has been utilized to predict UV-visible absorption spectra for these same compounds. Curcuminoids' UV-vis spectra were modeled using several DFT functionals including the popular B3LYP and CAM-B3LYP, specifically built to model electronic excitations. All methods utilized the 6–311++G** basis set for all atoms and implicit solvent modeling using the conductor-like polarizable continuum model (C-PCM). The quality of spectral matching for the various density functionals are presented as are the predictive strengths of TD-DFT in general for UV-vis spectra for this class of compounds.
College
College of Science & Engineering
Department
Chemistry
Campus
Winona
First Advisor/Mentor
Joseph West
Second Advisor/Mentor
Valeria Stepanova (Viterbo University)
Start Date
4-19-2023 10:00 AM
End Date
4-19-2023 11:00 AM
Presentation Type
Poster Session
Format of Presentation or Performance
In-Person
Session
1b=10am-11am
Poster Number
13
Investigation of Substituent Effects on the UV-vis Spectra of Curcuminoids and Validation of TD-DFT Methods for their Prediction
An array of curcuminoids - analogues of the turmeric extract, curcumin - have been spectroscopically analyzed to compare absorption shifts caused by changes to substituent variations on the terminal phenyl rings. A Hammett-type analysis was conducted in hopes of providing a qualitatively predictive approach for targeting the synthesis of new curcuminoids that absorb at specific wavelengths. In conjunction with this, the time-dependent density functional theory (TD-DFT) approach has been utilized to predict UV-visible absorption spectra for these same compounds. Curcuminoids' UV-vis spectra were modeled using several DFT functionals including the popular B3LYP and CAM-B3LYP, specifically built to model electronic excitations. All methods utilized the 6–311++G** basis set for all atoms and implicit solvent modeling using the conductor-like polarizable continuum model (C-PCM). The quality of spectral matching for the various density functionals are presented as are the predictive strengths of TD-DFT in general for UV-vis spectra for this class of compounds.
