Nitrile Vibrational Lifetimes as Probes of Local Electric Fields

Copyright and License (English)

© 2024 American Chemical Society.

Acknowledgement (English)

P.A.K. thanks: Dr. Tomislav Begušić, for patient explanations of theoretical methods; Dr. K.L. Kelvin Lee and Dr. G. Stephen Kocheril, for valuable guidance on a variety of topics, including hardware and software considerations for computational chemistry; Nathanael Kazmierczak and Jax Dallas, for insightful discussions on a variety of topics, including time-domain lineshapes; Anwesha Maitra and Anuj Pennathur, for willingness to assist in the validation of our DFT methods on benzonitrile; Benjamin Spector, for helpful discussions on the nature of energy transfer in molecular systems; Dr. Ryan Leighton, for thorough proofreading of the manuscript; and Dr. Jacob Kirsh, for illuminating discussions on the nature of the vibrational Stark effect. P.A.K. is grateful for financial support from a National Science Foundation Graduate Research Fellowship (DGE-1745301) and a Hertz Fellowship. The computations presented here were conducted with the Resnick High Performance Computing Center, a facility supported by the Resnick Sustainability Institute at the California Institute of Technology. We thank the Caltech Beckman Institute Laser Resource Center for research resources. This work was supported by a National Institutes of Health Director’s New Innovator Award (DP2 GM140919-01 for L.W.) and an Alfred P. Sloan Research Fellowship (L.W.). L.W. is a Heritage Principal Investigator supported by the Heritage Medical Research Institute at Caltech.

Funding (English)

P.A.K. is grateful for financial support from a National Science Foundation Graduate Research Fellowship (DGE-1745301) and a Hertz Fellowship. The computations presented here were conducted with the Resnick High Performance Computing Center, a facility supported by the Resnick Sustainability Institute at the California Institute of Technology. We thank the Caltech Beckman Institute Laser Resource Center for research resources. This work was supported by a National Institutes of Health Director’s New Innovator Award (DP2 GM140919-01 for L.W.) and an Alfred P. Sloan Research Fellowship (L.W.). L.W. is a Heritage Principal Investigator supported by the Heritage Medical Research Institute at Caltech.

Contributions (English)

P.A.K., H.W., D.L., and L.W. conceptualized the work. P.A.K. developed and benchmarked the convolution fitting method, performed the DFT calculations, acquired the BonFIRE spectra, and analyzed the data. H.W. and D.L. provided technical guidance. D.L. and N.N. acquired the UV–vis, fluorescence, and FTIR spectra. L.W. supervised the experiments, provided resources, and acquired funding. P.A.K. and L.W. drafted the manuscript. All authors have revised, edited, and given approval to the final version of the manuscript.

Data Availability (English)

• Methods; Rh800 electronic absorption and emission spectra; solvent reaction field theory; theory of BonFIRE spectroscopy; calculation of the instrument response function; simulation of convolution lineshapes and fitting benchmarking; example raw data and fits of BonFIRE time-domain spectra; theory of intramolecular vibrational energy redistribution; inference of Rh800 nitrile lifetimes from steady-state line widths; validation of DFT methods with benzonitrile; Rh800 DFT results; self-consistency of nitrile vibrational lifetime IVR calculations; summary of Rh800 nitrile vibrational lifetimes; absolute term contributions to the assigned IVR decay pathway; vibrational lifetime shifts in protic solvents; references; appendix: code for simulation and fitting of convolution lineshapes (PDF)

• Spectral data, fitting simulation results, computed normal-mode frequencies, and nitrile-stretch cubic force constants of Rh800 (XLSX)

Conflict of Interest (English)

The authors declare no competing financial interest.