Investigation of the C—CN Bond Activation of Fluorinated Benzonitriles with [Ni(dmpe)] and Dft Benchmarking Study with [Ni(dippe)]

Author

Dominique C. Gallegos, The University of Texas Rio Grande Valley

Date of Award

5-2021

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

First Advisor

Dr. Tülay A. Ateşin

Second Advisor

Dr. William D. Jones

Third Advisor

Dr. Shervin Fatehi

Abstract

Carbon-carbon bond activation has become a rapidly growing area of research due to its extensive range of applications. Despite the significant progress that has been made in this field, the cleavage of kinetically inert and thermodynamically stable C—C σ-bonds under mild homogeneous conditions remains a challenge. The activation is primarily limited to systems in which either relief of strain or aromatization serves as a driving force. A notable exception to this is the oxidative addition of unstrained C—CN bonds of nitriles. In this study, we are looking at the effect of fluoro substituents. We hypothesized that the number of ortho-F substituents would affect the product stability, rather than the total number of fluoro substituents. The benzonitrile substrates investigated are the 2-F, 3-F, 4-F, 2,6-F2, and 3,5-F2benzonitriles. The effects on the C—CN bond activation reaction of the fluorinated benzonitriles were investigated using [Ni(dmpe)] as a model for [Ni(dippe)] with DFT calculations. Both experimental and DFT calculation results have shown that there is a very good correlation between the stability of the C—CN bond activation products and the number of o-fluoro substituents. Although the C—C bond activation barrier is relatively constant with a slightly higher barrier for 2,6-F2 substrate due to steric hindrance, the activation barriers for the C—C bond elimination show a good correlation with the number of o-F substituents. For the future work, we will continue the DFT analysis with [Ni(dippe)] using the results from our benchmarking study.

Comments

Copyright 2021 Dominique C. Gallegos. All Rights Reserved.

https://go.openathens.net/redirector/utrgv.edu?url=https://www.proquest.com/dissertations-theses/investigation-c-cn-bond-activation-fluorinated/docview/2561943818/se-2?accountid=7119

Recommended Citation

Gallegos, Dominique C., "Investigation of the C—CN Bond Activation of Fluorinated Benzonitriles with [Ni(dmpe)] and Dft Benchmarking Study with [Ni(dippe)]" (2021). Theses and Dissertations. 865.
https://scholarworks.utrgv.edu/etd/865