EDTA sites [ENDORSED]

[606176900]

I know EDTA is a hexadentate, but is there a reason the lone pairs are not shown on the Oxygens are double bond.Is it because the molecule can't bend there and bind to the metal because of the pi bond?

[Chem_Mod]

This drawing did not put any lone pairs on any of the atoms.

Remember in class I discussed the COO- has resonance, therefore any of the lone pairs on the oxygen atoms can bind to a transition metal cation (but only one oxygen atom per COO- can bind at any one time). There are 4 COO- each with one bond to the TM cation.

Each N atom has a lone pair can bind to the transition metal cation. Another 2 bonds.

Total = 6 bonds (hexadentate)