Textbook 9C Question #5 part b

[Bailey Giovanoli 1L]

The book asks whether the ligand is polydentate and if so to determine the maximum number of places the ligand can bind simultaneously.
You are given CO3 with a -2 charge. When I draw the structure I see that one of the oxygen has a double bond. Therefore, it will not want to bind because it is stable. therefore, the other two oxygens each have a charge of -1 and will want to bind. I determined the ligand was bidentate but was confused when I examined the solution and noticed it said it could be bi or monodentate. I was wondering how the ligand could be monodentate. Does anyone have an explanation?

[Taylor K 2D]

This is a really good question. I would assume that it could be monodentate because of its shape and the angles between the two single-bonded oxygens preventing it from successfully bonding to the same metal but I honestly don't know. I found this link from a 2014 chem community post on the same topic but that's about all I could find.

viewtopic.php?t=4517

[Bailey Giovanoli 1L]

Ohhh I think I understand what you're saying, but let me clarify. It could be monodentate because the shape allows for another molecule to come and bond to both regions simultaneously. This is because the Oxygens are close enough together in terms of shape, right? In that case, it would also be a chelating complex, right?