Investigating Highly Sulfated Cyclodextrinsfor EnantiomericSeparations of Transition Metal DiimineComplexes Using Capillary Electrophoresis

PAC Gym

For chiral separations, resolving agents such as potassium antimonyl-d-tartrate and disodium dibenzoyl-L-tartrate salts have been utilized as buffer additives to resolve transition metal (TM) complexes of the type [M(diimine)3]n+or [M(diimine)2X2]n+in capillary electrophoresis (CE). The tartrate salt additives work well with some ligand systems, but have drawbacks, such as the limited maximum solubility of potassium antimonyl-d-tartrate. To find a solution to the limitation of the tartrate systems, highly sulfated cyclodextrins (HS-CD) were introduced due to the potential that the resolving agent could have different selectivities and resolving capabilities than previously observed. Tris-heteroleptic, bis-homoleptic bis-monodentate, bis-heroleptic bidentate, tris-homoleptic, and bis-heteroleptic bis-monodentate TM complexes were studied with HS-CDs, native CDs and other derivitized CDs. The ? and gvarieties of HS-CD, HS-?-CD and HS-g-CD, in concentrations of 10-60 mM, were successful at providing complete electrophoretic resolution. Potassium antimonyl-d-tartrate and disodium dibenoyl-L-tartrate were ran as a comparison to the HS-CDs.