Date of Award
Honors Thesis (Open Access)
Colby College. Chemistry Dept.
Dr. Dasan M. Thamattoor
Previous studies have shown that the photolysis of phenanthrene-based cyclopropyl precursors can generate carbenes. In this work, a novel phenanthrene precursor was synthesized and photolyzed to generate the dimethylalkylidene carbene, which was subsequently trapped by cyclohexene. The car- bene was not prone to an internal rearrangement as some other carbenes are, and instead favored the intermolecular addition reaction. The precursor also underwent a rearrangement via pericyclic processes. A theoretical analysis of the potential energy surface of the system is presented using coupled cluster and density functional methods. Preliminary analysis for the precursor via time-resolved laser flash photolysis (LFP) was performed. Future experiments include more comprehensive LFP studies on this system in addition to experiments to isolate the elusive rearrangement to 2-butyne. This work provides a safe and synthetically viable route to generate and trap alkylidene carbenes. These alkylidene carbenes provide interesting opportunities to study the migratory aptitudes of various substituents, and provide a fascinating plethora of opportunities to study such intermediates both experimentally and theoretically.
carbenes, organic chemistry, photochemistry, alkylidenes, ketenes, dipheylketene, dimethylalkylidene
Recommended CitationHardikar, Tarini S. and Hardikar, Tarini, "Photochemical Generation of Carbenes and Ketenes from Phenanthrene-based Precursors Part I: Dimethylalkylidene Part II: Diphenylketene" (2017). Honors Theses. Paper 948.