pubs.acs.org
3D-Printed Multicolor Molecular Orbital Models for a Second-Semester Organic Chemistry Course
We have developed a set of multicolor 3D-printed molecular orbital models associated with topics taught in a second semester organic chemistry course at Pomona College. The set includes the following: (1) π molecular orbitals (MOs) in benzene; (2) water sp- and p-type lone pair orbitals; (3) valence bond and π-MO models of amide stability and reactivity; (4) formaldehyde (neutral, H+, and Li+ complexes) sp- and p-type lone pair and π/π* orbitals; (5) orbital interactions and the Bürgi–Dunitz angle in a cyanohydrin transition state; (6) acetaldehyde enolate π-MOs; (7) orbital interactions in an enolate alkylation transition state; (8) orbital interactions in a lithium enolate aldol transition state; (9) benzyne πHOMO and π*LUMO orbitals; (10) n−σ* orbital interaction in the water dimer intermolecular hydrogen bond; (11) peptide α-helix structure and n−σ* orbital interaction in an intramolecular i, i + 4 hydrogen bond; (12) anomeric effect (nO–σ*CO orbital interaction) in a carbohydrate model compound. The models provide insights regarding aspects of π molecular orbital theory, stability, reactivity, and mechanistic “arrow pushing”. A hobby-grade five-color 3D fused deposition modeling (FDM) printer is used to make the models, which are sized to provide compact take-home class handouts and kits for each student. The models are fabricated with orbital bisections and text annotations to enhance information content. Student perceptions of this set of 3D-printed molecular models and their use in the classroom are generally favorable. 3D Manufacturing Format (3MF) model files are available in the Supporting Information for this article.
