Ketcher + dative bonds

[skearnes]

It would be great if Ketcher supported dative bonds. We could either try to add this functionality ourselves or find another editor that already supports this feature.

[skearnes]

Opened an issue: epam/ketcher#68

I don't know anything about their codebase, but it seems like some additions to https://github.com/epam/ketcher/blob/master/src/script/chem/struct/bond.js and its dependencies might be a good place to start.

Dative bonds have support in v3000 molfiles as bond type 9; see http://help.accelrysonline.com/ulm/onelab/1.0/content/ulm_pdfs/direct/reference/ctfileformats2016.pdf.

[skearnes]

#58 adds dative bonds in molfiles; we still need to get them into the SMILES.

[bdeadman]

Confirmed that Ketcher can now create dative bonds in ORD, and the molfile shows dative bonds as type "9". I haven't found confirmation that this is the correct value to describe dative bonds.

The SMILES string is not generated when the structure includes a dative bond.