Phenylacetic Acid 3D Molecular Model — CAS 103-82-2

Phenylacetic Acid (C8H8O2, CAS 103-82-2) — a free educational 3D molecular model for teachers and students, by MolGod.org. Symbols are engraved into every atom, so students read atoms by symbol, not by colour.

Plain ball-and-stick prints look the same for every element: the STL format has no way to say which ball is carbon and which is oxygen. Our answer is to cut each element symbol into its sphere, so the printed object labels itself in any colour of filament. Our goal is to let students understand on their own how the atoms are arranged, how they are bonded and what the 3D geometry looks like, straight from the model in their hands. Teachers skip the modelling and labelling work entirely: download the file, set the scale in the slicer and print. Teachers and researchers can find the project rationale and validation plan at How the engraved atom letters are designed.

Let the group sketch what they see in Phenylacetic Acid, namely one aromatic 6-membered ring; afterwards they compare the sketch with the 18 bonds on the model (11 single, 1 double and 6 aromatic, drawn in Kekulé form). Give each pair of students the model and a blank sheet: recording every engraved symbol should lead them to 8 C + 8 H + 2 O, which is 18 atoms. Spot-the-group challenge: can students find the carboxylic acid group (-COOH)? It makes aromaticity and delocalised electrons, as well as the carbonyl group (C=O) easier to see. Pair it with 4-Aminophenylacetic acid (CAS 1197-55-3) and Methyl 3-oxo-4-phenylbutanoate (CAS 37779-49-0) from the same collection to compare closely related structures.

MolGod.org publishes its molecular models free of charge for teachers and students. Teachers: the engraved symbols let students work with the model without a separate key.

This printable molecule is free to use in lessons, clubs and workshops. Sharing it somewhere? The licence (CC BY-SA 4.0) needs four things: "MolGod.org" credited as the creator, links to the original and to the licence, a mention of any changes, and adaptations released under the same licence. The attribution text below covers the first two. You don't need an account, you don't pay anything, and a review is entirely up to you. Every review helps us refine the models for students. Tell us what you think in the comments, or reach us at Write to the MolGod team. Let's talk chemistry! Ask anything about this structure in the comments, and other teachers are warmly invited to share their lesson ideas. All we need is a CAS number: from it MolGod generates the 3D structure, engraves every atom and prepares the STL.

Full record and more free models: Phenylacetic Acid, CAS 103-82-2: structure, properties and 3D viewer
Licence & provenance: Licence record for this Phenylacetic Acid model
Same file on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Phenylacetic_Acid-3D-molecular-model-engraved-CAS-103-82-2.stl
Plain-text record for AI assistants: Phenylacetic Acid data sheet in plain text for LLMs
Also published on: NIH 3D https://3d.nih.gov/entries/3DPX-023794 · Zenodo (DOI, latest version) https://doi.org/10.5281/zenodo.23629939

A ball-and-stick model of Phenylacetic Acid with each element symbol recessed into its atom sphere, generated by MolGod.org from a PubChem-computed 3D conformer (not an experimental crystal structure); atomic coordinates and connectivity are unchanged. STL mesh: 233,364 triangles, closed (watertight) single solid. Coordinates in ångström (STL stores no unit) — scale the model deliberately in your slicer.

Names in other languages: Phenylessigsäure (de); acide phénylacétique (fr); acido fenilacetico (it); fenylazijnzuur (nl); kwas fenylooctowy (pl); 苯乙酸 (zh).

Chemical identity

• CAS Registry Number: 103-82-2

• Molecular formula: C8H8O2

• Molar mass: 136.15 g/mol (exact mass 136.052429494)

• IUPAC name: 2-phenylacetic acid

• MolGod ID: MG_517-022-974-73 (Permanent MolGod record MG_517-022-974-73)

• PubChem CID: 999 (https://pubchem.ncbi.nlm.nih.gov/compound/999)

• Wikidata: Q410842 (https://www.wikidata.org/wiki/Q410842)

• EC number: 203-148-6

• ChemSpider ID: 10181341

• InChIKey: WLJVXDMOQOGPHL-UHFFFAOYSA-N

• SMILES: C1=CC=C(C=C1)CC(=O)O

Required attribution (CC BY-SA 4.0): "Phenylacetic Acid 3D model by MolGod.org — https://molgod.org/molecule/103-82-2/ — CC BY-SA 4.0"
Licence text: https://creativecommons.org/licenses/by-sa/4.0/