INDUCED CIRCULAR-DICHROISM IN ACHIRAL AND RACEMIC CHIRAL COMPLEXES

Induced Circular Dichroism (CD) in a number of symmetric complexes such as [Cr(NH3)(6)](3+), [Ni(NH3)(4)](2+), [Ni(NH3)(6)](2+), [Co(NH3)(4)Cl-2](+), and racemic dissymmetric complexes like [Co(en)(3)](3+), [Ni(en)(3)](2+), [Cr(en)(3)](3+) in the presence of L(+) tartaric acid (2.5 M) solution are reported and explained on the basis of outer-sphere complexation via hydrogen bonding mechanism. A number of the complexes such as [Ni(NH3)(6)](2+), [Ni(NH3)(4)](2+) cis-[Co(NH3)(3)](2+), [Ni(en)(2)](2+), though similar to [Co(NH3)(6)](3+), or [Co(en)(3)](3+), do not show induced CD bands in the visible region in the presence of L(+) tartaric acid. These observations indicate that hydrogen bonding is not the only mechanism for outer-space complexation in many systems.