20th Annual Student Research Conference
Science
A Computational Study on the Effect Alpha Nucleophiles have on the Energy of Reaction for Phosphonate Esters
Erich R. Kuechler
Dr. Eric V. Patterson, Faculty Mentor
Alpha-nucleophiles demonstrate an increased reactivity when compared to analogous normal nucleophiles. This study examines the differences observed between the normal nucleophile hydroxide and the alpha-nucleophile hydroperoxide in their reactions with phosphonate esters. The energy of reaction is highly dependent on both the nucleophile as well as the leaving group attached to the original ester. Depending on the quality of the leaving group, it has also been observed that the reaction may undergo either a concerted SN2(P) reaction or a multi-step substitution reaction involving a trigonal bipyramidal intermediate. The leaving group of the phosphate ester was varied systematically so trends in both the barrier for the nucleophilic attack and the leaving group loss could be determined. Leaving groups used in the study included fluorine, chlorine, methoxide and thiomethyl ligands. This study was conducted computationally and all calculations in this study were run using Gaussian03 at the MPWB1K/6-31+G(d,p) level of theory.
Keywords: computational, phosphonate, ester, nucleophile, phosphonate ester, Gaussian, alpha, alpha-nucleophile
Topic(s):Chemistry
Presentation Type: Oral Paper
Session: 45-4
Location: VH 1212
Time: 2:00 pm