Yeah, I'm also a bit surprised by this. I need to investigate a bit, but I guess that it's an unexpected interaction between a couple different pieces of code connected with valence detection and aromaticity perception. Here's a bit of support for that:
In [11]: m2 = Chem.MolFromSmiles('C#n1ccnc1') In [12]: Chem.Kekulize(m2,clearAromaticFlags=True) In [14]: m2.UpdatePropertyCache() [16:52:39] Explicit valence for atom # 1 N, 5, is greater than permitted --------------------------------------------------------------------------- ValueError Traceback (most recent call last) <ipython-input-14-504441a3d62f> in <module> ----> 1 m2.UpdatePropertyCache() ValueError: Sanitization error: Explicit valence for atom # 1 N, 5, is greater than permitted Thanks for reporting the problem! On Sat, Feb 9, 2019 at 2:59 AM Steven Kearnes via Rdkit-discuss < rdkit-discuss@lists.sourceforge.net> wrote: > I thought more about this as I was driving home. AFAICT neither of these > structures obeys Huckel's rule. Also, I noticed that both nitrogens have > GetTotalValence() == 3, which really seems odd. > > On Fri, Feb 8, 2019 at 5:03 PM Steven Kearnes <kear...@google.com> wrote: > >> C=n1ccnc1 >> C#n1ccnc1 >> >> I get that the extracyclic bonds contribute pi systems that enable >> aromaticity, but I don't know why the nitrogens don't have formal charges >> in the resulting Mol object. Note that only the first molecule matches >> anything in PubChem >> <https://pubchem.ncbi.nlm.nih.gov/compound/91511624#section=Top>, and it >> has a formal charge there. >> >> Thanks, >> Steve >> > _______________________________________________ > Rdkit-discuss mailing list > Rdkit-discuss@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/rdkit-discuss >
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