Phthalocyanines of metals of the first transition series. Part II. Influence of the crystal features on the interaction with nitric oxide and on the M–(NO) moiety

Abstract

No interaction has been observed between nitric oxide and the α-forms of Cr–pc, Fe–pc, and Co–pc. The different behaviour of the α-forms from that of the corresponding β-forms may be accounted for on the basis of their different crystal features. A detailed study of the infrared spectra (region 4000–650 cm.^–1) of the nitrosyl derivatives prepared from the β-forms of Cr–pc, Mn–pc, Fe–pc, and Co–pc shows that steric factors, associated with the arrangement of the molecules in the crystal lattice, are of especial importance in determining the manner of NO–metal binding.