This entry presents Pentamidine (C19H24N4O2; CAS 100-33-4; PubChem CID 4735) as a 3D-printable ball-and-stick model in which every atom carries its engraved element symbol (C, H, N, O), so the model can be read without a colour key. Atomic coordinates come from the PubChem-computed 3D conformer (not an experimental crystal structure); coordinates and connectivity are unchanged.

Structure at a glance

• 49 atoms: 19 C, 24 H, 4 N, 2 O

• 50 bonds: 36 single, 2 double, 12 aromatic

• Two 6-membered rings, both aromatic

• Functional groups: two ether linkages (C-O-C)

• Four hydrogen-bond donors and four acceptors (computed)

• Fraction of sp3-hybridised (tetrahedral) carbon atoms: 0.26 (computed)

Use in teaching

• Counting task: students tally the engraved symbols (19 C, 24 H, 4 N, 2 O; 49 atoms) and rebuild the formula C19H24N4O2 from the model alone.

• Aromaticity: identify the two aromatic rings and the 12 bonds recorded as aromatic; the model draws them as one Kekulé structure (alternating single and double bonds), while in the real molecule they are delocalised, intermediate between single and double.

• Functional groups: find the two ether linkages (C-O-C) on the model and name each one.

File and printing

STL mesh of 607,522 triangles, a closed (watertight) single solid. Coordinates are in ångström and STL stores no unit, so scale the model deliberately in your slicer. Measured bounding box: 14.91 × 14.853 × 6.136 Å; at scale factor 10 (1 Å to 10 mm, file read in millimetres) the print measures about 149.1 × 148.5 × 61.4 mm. SHA-256: 6703f3ef9ec3c3a187a3220a92ea2c88910818b61a38dea4ee888f633846c6d7.

Validation

• InChIKey identical to the PubChem record (PubChem FTP SDF, file dated 2026-10-08): XDRYMKDFEDOLFX-UHFFFAOYSA-N

• Molecular formula and hydrogen-bond donor/acceptor counts identical to PubChem

• Mesh: triangle count in the header equals the actual count; 0 edges not shared by exactly two triangles; 1 connected solid; SHA-256 equal to the published file

Source, licence and identifiers

Full record: molgod.org/molecule/100-33-4 · Licence and provenance record: molgod.org/licenses/stl/100-33-4 · Same file on Wikimedia Commons: File:Pentamidine-3D-molecular-model-engraved-CAS-100-33-4.stl

• MolGod ID: MG_172-244-784-72

• Wikidata: Q416206

• EC number: 202-841-0

• ChemSpider ID: 4573

• IUPAC name: 4-[5-(4-carbamimidoylphenoxy)pentoxy]benzenecarboximidamide

• InChIKey: XDRYMKDFEDOLFX-UHFFFAOYSA-N

• SMILES: C1=CC(=CC=C1C(=N)N)OCCCCCOC2=CC=C(C=C2)C(=N)N

• Molar mass 340.4 g/mol (exact mass 340.18992602)

Licence: CC BY-SA 4.0 (licence text). Required attribution: "Pentamidine 3D model by MolGod.org — https://molgod.org/molecule/100-33-4/ — CC BY-SA 4.0".