Products Cited in Publications Worldwide Hammett Study of the Resonance-Assisted Hydrogen Bond in Substituted O-Acyl Naphthols and the Development of a Computational Chemistry Exercise for the Freshman-Level General Chemistry Curriculum

Hammett Study of the Resonance-Assisted Hydrogen Bond in Substituted O-Acyl Naphthols and the Development of a Computational Chemistry Exercise for the Freshman-Level General Chemistry Curriculum

Jones, Jordan Anthony

Abstract

Part I: Resonance assisted hydrogen bonds (RAHBs) are among the strongest forms of hydrogen bonding known to occur and are found in specific intramolecular hydrogenbonding systems. Two series of ortho-acylnaphthols that undergo this type of hydrogen bonding were synthesized. One series was substituted on the 4-naphthol position (Y), and the other substituted on the p-benzoyl position (X), where X or Y = OCH3, CH3, H, Br, Cl, or NO2. A Hammett study was carried out using 1H NMR and 13C NMR to determine the nature of the electronic effects on the RAHB in this system. Previous research has shown that pbenzoyl substituents cause the enolic 1H NMR shift to increase when electron-donating groups are in the para position, exhibiting shifts up to 14.01ppm. The opposite trend has now been observed with 4-naphthyl substituents; the enolic 1H NMR shift increased as the electron-withdrawing character of the substituent increased, exhibiting shifts up to 14.60ppm. Part II: A computational chemistry exercise intended for second-semester general chemistry students has been developed and used in the laboratory curriculum at a regional university. Students used the Avogadro software to build, optimize, and measure bond lengths and angles in simple organic molecules, focusing on the functional groups. The exercise was used as an out-of-class exercise for students to review VSEPR theory while simultaneously introducing them to organic functional groups and computational chemistry fundamentals. A pre-test and post-test were used to evaluate the educational efficacy of the exercise, and a survey was conducted to determine if students found the exercise helpful. Data from the student responses were also collected and evaluated to determine if the Avogadro software’s default optimization parameters are adequate for this application.

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4-Methylnaphthalen-1-ol

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