EFFECT OF SYMMETRY ON VISIBLE-BAND INTENSITIES OF CUPRIC $CHELATES^{*}$

$^{*}$Supported by NSF, University of Illinois Research Board, and an Alfred P. Sloan Research Fellowship.Author Institution: Noyes, Chemical Laboratory, University of Illinois“Using the probable symmetry of several cupric chelates dissolved in $CHCl_{3}$ or $C_{3}H_{3}N$, one can infer some rational trends in the electric dipole intensity of the copper d-d absorption bands. It is postulated that the centric molecules show only weak $(\epsilon < 100)$ vibrationlly induced transitions; acentric molecules should have higher transition moments. The intensity in each case, should increase when the compound is monopyridinated. Spectra, of solutions of two series of chelates chosen for their symmetry variations are in reasonable accord with the predictions. Judiciously used, intensity of visible absorption bands of a new cupric species can provide useful about its geometry, more frequent use of this evidence is recommended.