Evidence for a Nitric Oxide Complex with Cupric Fluoride

Abstract

ALTHOUGH it has been recognized for some time that nitric oxide and cupric chloride or bromide combine in non-aqueous solvents to form nitrosyl complexes¹, the composition of these has only recently been determined². The deep blue colour is due to the covalent CuX ₂.NO (possibly solvated) : this compound dissociates into colourless ions : and this has been responsible for erroneous structures suggested for the complexes. Unsuccessful attempts have been made to prepare nitrosyl complexes in alcoholic solution from other cupric salts, including the fluoride³. Recently, a study of the variation of dissociation constant of the cupric chloride nitrosyls as a function of the dielectric constant of the alcohol has been made⁴ : some results are shown in Table 1.