AN INTERPRETATION OF CIRCULAR DICHROISM AND ELECTRONIC SPECTRA OF SALICYLALDIMINE COMPLEXES OF SQUARE-COPLANAR DIAMAGNETIC NICKEL(2)

The electronic absorption spectrum and the associated circular dichroism of the complex N,N′-bis-(salicylidene)-(–)-propylenediaminonickel(II), [Ni(–)pn(sal)2], have been measured. The circular dichroism absorption reveals electronic transitions which are not resolved in the ordinary absorption spectrum and, in addition, allows for the identification of magnetic dipole transitions. A comparison of the two types of spectra shown by the free ligand (N,N′-bis(salicyiidene)-(–)-propylenediamine) and its zinc complex with that of the nickel complex suggests a consistent explanation for the electronic provenance of the transitions in both the ligand and its metal complexes. © 1968, American Chemical Society. All rights reserved.