Pressure Effects in Nickel Dimethylglyoxime and Related Chelates

Abstract

The effect of pressure on the absorption peak characteristic of the solid phase of certain metal chelates has been measured for Ni(DMG)2, Pd(DMG)2, Pt(DMG)2, Ni nioxime, Pd nioxime, Ni benzoxime, and Ni heptoxime. The peak shifts strongly red with pressure. At high pressure the shift levels off for nickel, tends to reverse for palladium and reverses strongly for plantinum. There is considerable pressure broadening. These and other related observations are consistent with the assignment of the transition as from the A1g (or A1g and Eg) ground state to the A2u (pz) excited state.