Do-It-Yourself 5-Color 3D Printing of Molecular Orbitals and Electron Density Surfaces

Abstract

This report outlines an approach for preparing 5-color 3D printed plastic models of molecular orbitals and electron density surfaces using a hobby-grade 3D printer. Instructions are provided for preparing 3D orbital and electron density surface (EDS) models using solid or mesh representations in ground state and transition state structures. We show that the information content of 3D orbital and surface models can be enhanced with text annotation, bisection, strut and dashed bond placement, and composite orbital-EDS model constructions. Example prints illustrate orbital concepts in organic and inorganic chemistry, such as the ethyl cation (σ–p hyperconjugation), methane (hybridization and C–H bonding), ethane (σ–σ* hyperconjugation in the staggered and eclipsed conformations), 2-hydroxytetrahydropyran (the anomeric effect/n−σ* hyperconjugation), the water dimer (hydrogen bonding/n−σ* overlap), ethylene, 1,3-butadiene, and benzene (π molecular orbitals), Re2Cl8 2–, and U2(COT)2 (metal–metal quadruple bonds). Transition state models illustrate orbital interactions in the SN2 reaction of cyanide with methyl, ethyl, and isopropyl chloride and in a hydroboration reaction of BH3 with propene. Composite EDS models of methyl and isopropyl chloride (for exploring their relative reactivities as SN2 electrophiles) and methylcyclohexane (visualizing 1,3-diaxial interactions) are described. Student perceptions of a multicolor 3D orbital print used in an introductory organic chemistry laboratory course are reported.

Integrating Computational Chemistry into Secondary School Lessons

“…Similarly to previously published exercises, − ,, students were asked to visualize different hydrogen orbitals. By allowing students to engage with wave functions of a single electron in a hydrogen atom, they can visually grasp the significance of quantum numbers, particularly the principal and orbital angular momentum quantum numbers.…”

“…Murphy et al 27 provide a student-friendly guide to molecular integrals, making complex quantum mechanical concepts more accessible. Garcia et al 28 explore 3D printing of molecular orbitals calculated by CC, offering a novel approach to visualizing complex molecular structures.…”

A Mobile Device Application for Visualizing Molecular Symmetry and Orbitals in Augmented Reality

“…To overcome some of the challenges in visualizing these concepts, educators often resort to using physical teaching aids to demonstrate and allow for hands-on learning activities in which students can manipulate real objects. These physical teaching tools include commercial kits, − homemade and everyday objects, − and more recently laser-cut or 3D-printed models. − Some limitations to these approaches are the associated costs for purchasing or constructing/printing models, the number of unique models available to instructors, limited quantities and timing of access to the physical models for student use, and the inability to visualize abstract concepts such as improper rotations or inversion centers.…”

Accessible 3D Printing: Multicolor Molecular Models from Consumer-Grade, Single Filament 3D Printers

“…Chemists have long used physical models to represent molecular structure, visualize chemical phenomena and, in the classroom, facilitate the understanding thereof . More recently, with the advent of inexpensive, consumer-grade 3D printers, bespoke 3D printed molecular models illustrating molecular structure, , electron density surfaces, , and molecular orbitals − are readily available. Although consumer grade printers are relatively inexpensive, the majority of consumer-grade 3D printers rely on fused deposition modeling (FDM) or resin 3D printing technology, additive manufacturing techniques that construct objects through sequentially added layers of a single-colored plastic filament or resin .…”

“…Commercial grade, multicolor 3D printers rely on selective laser sintering (SLS) or advanced inkjet-derived multijet technologies and are cost-prohibitive. Multicolor 3D printed molecular models are thus typically purchased through professional print services (i.e., Shapeways or Craftcloud), printer accessories, or customized through labor-intensive hand painting. , Here, we report a general procedure for multicolor 3D printed space-filling molecular models and models of molecular orbitals using freely available software that can be printed and assembled using accessible and affordable consumer-grade 3D printers.…”