bidentate ligands
Here's a short question to ponder for an April Friday afternoon.
Consider the dimethylthiocarbamate ligand (dtc, structure shown on p. 328 of Miessler & Tarr 4th edition), which can coordinate to metals in a bidentate fashion through both sulfur atoms. Why, on the other hand, does a ligand like oxalate coordinate through only one oxygen of the carboxylate resonance pair? (Oxalate is bidentate, but only because it has two carboxylate groups.)