Phthalocyanine trans-effect

The complexes frans-[Ru(NH3)4 P(OR)3 2] and trans-[Ru(NH3)4 P(OEt)3 P(OR)3 ], with R = methyl, isopropyl, or butyl, aquate to give a monophosphite product with rate constants which vary little with the nature of the complex or solvent composition (up to 80% ethanol). The results support the dissociative mechanism previously proposed for the triethyl phosphite complex. Trans effects are here dominated by 7T acceptor properties of these phosphite ligands. Trans effects in substitution in bis-ligand ruthenium (and iron) phthalocyanine complexes follow the order... 

The dioxygen ligand is said to be stabilized by the presence of strong (T-donors in the trans position. Such complexes are of specific interest as models of the active myoglobin center (473). Preliminary reports of a related copper(II) system have appeared (286). Studies on the effect of extraplanar Me SO coordination on phthalocyanine derivatives of cobalt (109) and iron (315-317) have been performed and show that, for example, the low-spin d iron(II) phthalocyanine complex dissolves in Me SO to give a diamagnetic blue solution which may be reacted further with donors such as imidazole, effecting replacement at the axial sites (62). 

The optical properties of pigments in the near infrared were studied by Taylor Di Bernardo reported anomalous spectrophotometric behavior of copper phthalocyanine—benzidine yellow mixtures. Brode and Wyman presented the absorption spectra of ten thio-indigo dyes in benzene and chloroform and discussed the effect of irradiation upon their cis-trans equilibria they also presented the spectra of nine of these dyes in H2SO4 in the range 210-800 m/i. 

---