Textbook problem 9C 5 part b

[kiara chan]

Which of the following ligands can be polydentate? If the ligand can be polydentate, give the maximum number of places on the ligand that can bind simultaneously to a single metal center:
(b) CO32−

Can CO32- be both monodentate and bidentate? b/c I understand that CO32- can bond with a metal ion that has a 2+ charge, but can't it also bond w/ a metal ion with a +1 charge, making it an anionic coordination compound resulting in a lewis base to attach as well?

[Sunny Xiao 1A]

Yes, carbonate can be both mono and bidentate. Both oxygens with a lone pair and negative charge can bind to a ligand. However, whether or not both oxygens are able to bind (due to the small 120 degree angle between the two) depends on the metal and its size/electronegativity likely.