👍 On Fri, Jan 22, 2021 at 9:01 AM Ivan Tubert-Brohman < ivan.tubert-broh...@schrodinger.com> wrote:
> I think there was some confusion between left and right in the original > message, but RDKit prefers the representation that preserves the octet at > the expense of having more formal charges: > > In [9]: mol = Chem.MolFromSmiles('O=I(=O)([O-])') > > > In [10]: Chem.MolToSmiles(mol) > > Out[10]: '[O-][I+2]([O-])[O-]' > > I don't think there's right and wrong here; it's just a matter of a > toolkit picking a canonical convention. > > Carboxylates are different in that the popular representation (C(=O)[O-]) > doesn't break the octet rule. But another interesting case is nitro groups: > > In [11]: mol = Chem.MolFromSmiles('CN(=O)=O') > > > In [12]: Chem.MolToSmiles(mol) > > Out[12]: 'C[N+](=O)[O-]' > > > Ivan > > On Thu, Jan 21, 2021 at 9:06 PM Peter S. Shenkin <shen...@gmail.com> > wrote: > >> It seems to me offhand RDKit's choice is analogous the way carboxylates >> are generally notated: >> >> R-C(=O)O- rather than R-C+(O-)O- . >> >> Both are legitimate and in fact equivalent upon application of >> chemical knowledge, but do you prefer the second representation for >> carboxylates? >> >> -P. >> >> >> >> >> >> On Thu, Jan 21, 2021 at 2:06 PM Jason Biggs <jasondbi...@gmail.com> >> wrote: >> >>> The RDKit will always convert iodate from the form on the left, with an >>> expanded octet on iodine and a single negative charge, into the form on the >>> right with all single bonds and a charge on every atom (image here >>> https://i.stack.imgur.com/hq3St.png). This happens no matter how I >>> import the molecule, from SMILES or from a file. The only way to avoid it >>> is to skip sanitization, which I'd rather avoid. >>> >>> Is this the desired behavior? >>> >>> Thanks >>> Jason >>> >>> [image: image.png] >>> >>> >>> >>> >>> _______________________________________________ >>> Rdkit-discuss mailing list >>> Rdkit-discuss@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/rdkit-discuss >>> >> _______________________________________________ >> Rdkit-discuss mailing list >> Rdkit-discuss@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/rdkit-discuss >> > -- -P. Sent from a cell phone. Pls forgive brvty and m1$tea@ks.
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