Molecule with S-Group exported as mol has problems in ISIS

Any molecule with S-GROUP (ie, SnBu3, SnMe3, OMe) drawn in MarvinSketch and then SAVED AS Mol file has problems in ISIS Draw 2.2.1.





It imports fine, but on expanding the residue (ie, the S-GROUP) it reports that "Valence Exceeded on Atoms" and has a strange bond to an *.





I'm assuming this is some misinterpretation of the connection point.





Also, if the structure is drawn out WITHOUT using S-groups, and then manually creating a group, contracting and exporting as a MOL, it works perfectly. ISIS opens it, does not complain when expanding or contracting the residue.





I've attached examples.





ISIS1 mol and mrv has an S-group, SnMe3 while


ISIS2 mol and mrv has a manually created group called SnMe3





ISIS.jpg shows how ISIS1 w/ S-Group looks when expanded in ISIS Draw.





Any reason why an S-GROUP would have such strange behavior?





Anyone else see this when saving as a MOL format and opening in other programs?





I'm going to test it further in ISISbase and chemdraw and see what happens as well.





NCM


FSCI

Hello, ISIS1.[mol|mrv] is certainly incorrect, bonds and atoms are missing from the SuperatomSgroup representation even in the MRV file. Apparently the bug comes forward when you are typing 'SnMe3' at the very first time. Until I fix it unfortunatelly you have to type the 'n' letter of the 'Sn' twice when you are drawing structures like that - thank you for the bug report.

Well, as I see even that workaround is giving the wrong SnMe3 abbreviated representation, so something is very screwed up with that group.

I'm seeing this behavior for all S-groups, although maybe the SnMe3 in particular does have problems.





The ISIS problem relates to the attachment points being exported as per the other thread. Again, a parameter in the export of a mol file to leave or remove all attachment points of S-groups would be nice.





I'm just wondering why this is different between S-groups and a manually created group? Shouldn't they both be essentially the same on export to MOL?





Anyhow...I'm done looking at it for the weekend. I'll report back next week what I see and try it with some other S-groups besides the 3-4 I tried.





Thanks for looking!





NCM


FSCI