Spin-orbit coupling in nitrite ion and nitrite salts

The absorption intensity of the³B₁ ¹A₁ transition of nitrite salts of the non-transition metals is markedly dependent on the metal counterion and is causative of the yellow-orange colors of the heavier-metal salts. It is assumed that spin-orbit coupling is responsible for this phenomenon; this assumption is investigated here using semi-empirical one-electron calculations and is validated. The subjects of covalent bonding in metal salts, charge transfer transitions in such systems and the S_j S₀ electronic spectroscopy of nitrite salts are also investigated.This work was supported by contracts between the United States Atomic Energy Commission — Biology Branch and the United States Air Force with the Louisiana State University.