Propidium iodide core
Athanor · official
C21H20N3+ · 314.4 g/mol
IUPAC name: 5-ethyl-6-phenylphenanthridin-5-ium-3,8-diamine
Also called PI, dead cell stain, flow cytometry
Names and identifiers
- IUPAC name
- 5-ethyl-6-phenylphenanthridin-5-ium-3,8-diamine
- Synonyms
- PI, dead cell stain, flow cytometry
+ 39 more
Ethidium, homidium, Ethidium cation, Babidium, Homidium cation, Homidium ion, 3,8-Diamino-5-ethyl-6-phenylphenanthridinium, EN464416SI, Phenanthridinium, 3,8-diamino-5-ethyl-6-phenyl-, RD-1572, DTXSID9048487, CHEBI:42478, 2,7-diamino-9-phenyl-10-ethylphenanthridinium, 3,8-diamino-5-ethyl-6-phenylphenanthridin-5-ium, 2,7-DIAMINO-10-ETHYL-9-PHENYLPHENANTHRIDINIUM, RefChem:921221, DTXCID9028461, Novidium, 5-ethyl-6-phenylphenanthridin-5-ium-3,8-diamine, AB00053825_07, CHEMBL284328, 5-ethyl-6-phenyl-phenanthridin-5-ium-3,8-diamine, BRN 3627183, UNII-EN464416SI, Spectrum_001500, HOMIDIUM [MI], Spectrum2_001587, Spectrum4_000198, Spectrum5_001263, UPCMLD-DP076, NCIMech_000529, cid_3624, Piperine & Ethidium bromide, NCIOpen2_009324, Reserpine & Ethidium bromide, SCHEMBL27609, KBioGR_000775, KBioSS_001980, 5-22-11-00352 (Beilstein Handbook Reference)
- Molecular formula
- C21H20N3+
- Empirical formula
- C21H20N3
- Molecular weight
- 314.4 g/mol
- Exact mass
- 314.16572
- CAS number
- 25535-16-4
- PubChem CID
- 3624
- Canonical SMILES
- CC[N+]1=C2C=C(C=CC2=C3C=CC(=CC3=C1C4=CC=CC=C4)N)N
- Isomeric SMILES
- CC[N+]1=C2C=C(C=CC2=C3C=CC(=CC3=C1C4=CC=CC=C4)N)N
- InChI
- InChI=1S/C21H19N3/c1-2-24-20-13-16(23)9-11-18(20)17-10-8-15(22)12-19(17)21(24)14-6-4-3-5-7-14/h3-13,23H,2,22H2,1H3/p+1
- InChIKey
- QTANTQQOYSUMLC-UHFFFAOYSA-O
- Molfile
Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.
Calculated
- Heavy atoms
- 24
- Rings
- 4
- Aromatic rings
- 4
- Fraction sp³ carbons (Fsp3)
- 0.1
- H-bond donors
- 2
- H-bond acceptors
- 2
- Rotatable bonds
- 2
- TPSA (Ų)
- 55.9
- Formal charge
- 1
- XLogP3
- 4.2 PubChem
- Complexity
- 419 PubChem
- Stereocenters
- None
- Double-bond geometry
- None specified
- Point group
- C1 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)
Elemental analysis
- C80.22%
- H6.41%
- N13.36%
Isotope pattern
Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.
Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.
Predicted
- log P
- 4.13 Crippen (Wildman and Crippen 1999)
- log S (water solubility)
- -4.88 ESOL (Delaney 2004), log mol/L
- Synthetic accessibility
- 2.49 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)
Drug-likeness: Lipinski’s rule of five
- Molecular weight ≤ 500: 314.41
- log P ≤ 5 (Crippen): 4.13
- H-bond donors ≤ 5: 2
- H-bond acceptors ≤ 10: 2
Passes all four rules.
¹³C NMR shifts, predicted
Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.
Safety
No GHS hazard classification was found in the sources.
Safety data sheets on the supplier’s page: EvitaChem, BenchChem, TargetMol.
Always read the supplier’s safety data sheet before working with it.
Spectra
- 13C NMRSpectraBase (Jeol FX-60)
- LC-MSMassBank Europe (LCMS-8045 (Shimadzu, Kyoto, Japan) · LC-ESI-QQ · POSITIVE) · MassBank Europe (LCMS-8045 (Shimadzu, Kyoto, Japan) · LC-ESI-QQ · POSITIVE) · MassBank Europe (LCMS-8045 (Shimadzu, Kyoto, Japan) · LC-ESI-QQ · POSITIVE)
Experimental spectra held by these sources; each link opens the source's own record.
Literature
Reading PubChem, OpenAlex and GSRS…
Bioactivity
Reading ChEMBL…
References
- [1]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
- [2]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
- ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
- ·Literature on PubChem
Data last updated 2026-10-14.