Applications of polymer films and Nujol mulls to spectroscopic studies at low temperatures: electronic spectra of chromate, dichromate, chlorochromate, manganate and permanganate ions at 12–77 K

Abstract

Electronic absorption spectra have been obtained for chromate, dichromate, chlorochromate, manganate and permanganate ions in argon and dinitrogen gas matrices, poly(vinyl alcohol) films and Nujol mulls at c. 12 and 77 K. All the ions showed well resolved vibrational progressions. There was a good correspondence for the data for caesium chromate between frozen gas matrices, polymer films and Nujol mulls and that previously obtained using single crystals, doped crystals and thin films. The relative ease, speed and inexpensiveness of procedures using polymer films and particularly mulls, which are described for the first time, makes them ideal for low temperature studies especially where gas matrix, organic glass and doped crystal studies are not feasible, e.g. potassium chlorochromate which is not volatile and which disproportionates in solution.