SPECTRA OF IONS WITH 9D ELECTRONS .I. SPECTRA OF COPPER(2) AND SILVER (2) IN PERCHLORIC NITRIC SULFURIC AND PHOSPHORIC ACID MEDIA

The spectra of solutions of CuCO3 in HClO4, H2SO4, HNO3 and H3PO4 and of AgO in HNO3 and H3PO4 were resolved into component Gaussian curves. In HClO4, H2SO4 and HNO3 for Cu, peaks were found at about 8000, 10,000 and 13,000 cm-1. Better resolution was often obtained by splitting the highest energy transition into a doublet separated by about 800 cm-1. The bands were assigned to the transitions dz2 → dx2 - y2, dxy → dx2 - y2 (Δo), and dzy,dxy → dx2 - y2. Reasons for the assignments were discussed and the ratio of the wave numbers of the 13,000 cm-2 to the 10,000 cm-1 band was proposed as a measure of tetragonal distortion, 1.70 being the limiting value for a square complex. Average values were 1.37 in HNO3, 1.26 in HClO4, and 1.22 in H2SO4. In H3PO4, bands were found at 8500 cm-1, 12,000 cm-1, and 13,250 cm-1. Results were explained on the basis of increased tetragonal distortion (ratio = 1.48) by assigning the 8500 cm-1 band the transition dxy → dz. Resolution of the spectra of solutions of AgO in HNO3 and H3PO4 showed lowest energy transitions at 16,250 cm-1 in HNO3 and 16,700 cm-1. These transitions were probably due to the d-d transition dxy → dx2 - y2 (Δ0). All other transitions were at least 21,000 cm-1 and were either charge transfer or d-d transitions. These assignments were in good agreement with the observation that Δ0 is about 50% higher for the second transition series than for the first series. © 1969.