EFFECT OF HALIDE COMPLEXATION OF CADMIUM(II) ON CD-113 CHEMICAL-SHIFTS

A unique combination of solution and solid-state 113Cd NMR experiments has been employed to elucidate the 113Cd chemical shifts of the individual halide complexes of CdX+, CdX2, CdX3-, and CdX42-, where X is CI-, Br-, and I-. The solution-state experiments made use of standard pulsed Fourier transform NMR techniques to examine the 113Cd chemical shift of aqueous 0.1 M Cd(C104)2 as a function of halide concentration. The solid-state experiments made use of cross-polarization/ magic angle spinning techniques to examine the 1l3Cd chemical shifts of a series of solid Cd(II)-halide complexes. By consideration of the appropriate multiple equilibria in solution together with,1l3Cd chemical shift “benchmarks” from solid-state Cd(II)-halide complexes, the ll3Cd chemical shifts for the individual Cd(II)-halide complexes were derived. The following shielding orders are observed: Cd2+ > CdCl+ > CdCl2 > CdCl64-≥ CdCl53- CdCl3> CdCl42- for the Cd(II)-chloride complexes, Cd2+ > CdBr+≃ CdBr2 > CdBr3≃ CdBr42- for the Cd(II)-bromide complexes, and Cd2+> Cdl+ > Cdl42- > Cdl3-for the Cd(ll)-iodide complexes. © 1979, American Chemical Society. All rights reserved.