Triazabicyclodecene (C7H13N3, CAS 5807-14-7) — a free educational 3D molecular model for teachers and students, by MolGod.org. Every atom carries its engraved element symbol, so no colour key is needed.

An STL file stores shape only, never colour, so a printed ball-and-stick model usually gives no clue which sphere is which element. MolGod adds what the STL format leaves out by engraving the element symbol into each atom of the printed structure. The project exists to put these files in teachers' hands, so that identifying atoms becomes quick and the lesson can move on to how atoms interact. Preparation time drops for the teacher too: there is nothing to model, colour or annotate before sending the file to the printer. The research behind the idea, and how we plan to test it, is described at The story behind these engraved molecule models.

Start with the ring system: Triazabicyclodecene has two 6-membered rings, fused along a shared edge; in total the model carries 24 bonds (23 single and 1 double). Use the engraved letters like a register: call out each element and tick it off until the class reaches 7 C + 13 H + 3 N (23 atoms altogether). It makes fused ring systems easier to see. Ask which carbons are tetrahedral and which are not; the answer should match an sp3 fraction of 0.86.

MolGod.org builds and releases these models at no cost for chemistry teaching. Teachers: give each table a model and have students write the formula from the engraved atoms.

The model is yours to download, print and teach with. 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. There is no registration, no payment and no obligation to rate it. Every review helps us refine the models for students. Tell us what you think in the comments, or reach us at Ask us for another molecule. Questions about the chemistry behind this molecule are welcome too: start a discussion in the comments and we will happily join in. We are glad to prepare a 3D model for any CAS number: contact us with the compounds you need.

Full record and more free models: Molecule page for Triazabicyclodecene (CAS 5807-14-7)
Licence & provenance: Where this Triazabicyclodecene model comes from and how you may use it
Same file on Wikimedia Commons: https://commons.wikimedia.org/wiki/File:Triazabicyclodecene-3D-molecular-model-engraved-CAS-5807-14-7.stl
Plain-text record for AI assistants: Machine-readable Triazabicyclodecene record (CAS 5807-14-7)
Also published on: Zenodo (DOI, latest version) https://doi.org/10.5281/zenodo.23954218

A ball-and-stick model of Triazabicyclodecene 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: 252,418 triangles, closed (watertight) single solid. Coordinates in ångström (STL stores no unit) — scale the model deliberately in your slicer.

Names in other languages: 1,5,7-Triazabicyclo(4.4.0)dec-5-en (de); 1,5,7-triazabicyklo[4.4.0]dek-5-en (pl); 1,5,7-三氮杂双环［4.4.0］癸-5-烯 (zh).

Chemical identity

• CAS Registry Number: 5807-14-7
• Molecular formula: C7H13N3
• Molar mass: 139.20 g/mol (exact mass 139.110947427)
• IUPAC name: 3,4,6,7,8,9-hexahydro-2H-pyrimido[1,2-a]pyrimidine
• MolGod ID: MG_845-826-642-14 (Triazabicyclodecene under MolGod ID MG_845-826-642-14)
• PubChem CID: 79873 (https://pubchem.ncbi.nlm.nih.gov/compound/79873)
• Wikidata: Q7840264 (https://www.wikidata.org/wiki/Q7840264)
• EC number: 227-367-1
• ChemSpider ID: 72164
• InChIKey: FVKFHMNJTHKMRX-UHFFFAOYSA-N
• SMILES: C1CNC2=NCCCN2C1

Required attribution (CC BY-SA 4.0): "Triazabicyclodecene 3D model by MolGod.org — https://molgod.org/molecule/5807-14-7/ — CC BY-SA 4.0"
Licence text: https://creativecommons.org/licenses/by-sa/4.0/

STL mesh: 252,418 triangles, closed (watertight) single solid. Coordinates in ångström (STL stores no unit) — scale the model deliberately in your slicer.