This entry presents 4-Nitroaniline (C6H6N2O2; CAS 100-01-6; PubChem CID 7475) 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

• 16 atoms: 6 C, 6 H, 2 N, 2 O

• 16 bonds: 9 single, 1 double, 6 aromatic

• One aromatic 6-membered ring

• Functional groups: one nitro group (-NO2) and one primary amino group (-NH2)

• One hydrogen-bond donor and three acceptors (computed)

• No carbon atom is sp3-hybridised

Use in teaching

• Counting task: students tally the engraved symbols (6 C, 6 H, 2 N, 2 O; 16 atoms) and rebuild the formula C6H6N2O2 from the model alone.

• Aromaticity: identify the aromatic ring and the 6 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 nitro group (-NO2) and the primary amino group (-NH2) on the model and name each one.

File and printing

STL mesh of 216,520 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: 6.037 × 6.037 × 4.522 Å; at scale factor 10 (1 Å to 10 mm, file read in millimetres) the print measures about 60.4 × 60.4 × 45.2 mm. SHA-256: dd56bf70baaf2084aa95433172343b3f3500a79545a7a6f2593b6b3fa4c99bc9.

Validation

• InChIKey identical to the PubChem record (PubChem FTP SDF, file dated 2026-10-08): TYMLOMAKGOJONV-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/100-01-6 · Licence and provenance record: molgod.org/licenses/stl/100-01-6 · Same file on Wikimedia Commons: File:4-Nitroaniline-3D-molecular-model-engraved-CAS-100-01-6.stl

• MolGod ID: MG_171-126-476-57

• Wikidata: Q419842

• EC number: 202-810-1

• ChemSpider ID: 13846959

• IUPAC name: 4-nitroaniline

• InChIKey: TYMLOMAKGOJONV-UHFFFAOYSA-N

• SMILES: C1=CC(=CC=C1N)[N+](=O)[O-]

• Molar mass 138.12 g/mol (exact mass 138.042927438)

Licence: CC BY-SA 4.0 (licence text). Required attribution: "4-Nitroaniline 3D model by MolGod.org — https://molgod.org/molecule/100-01-6/ — CC BY-SA 4.0".