Sulfoxide complexes electronic spectra

Electronic spectroscopy has been employed to study substitution reactions of sulfoxide complexes. An interesting example (104) is the reaction of [Fe(0-Me2S0) P+ with chloride ion. Addition of one equivalent of chloride ion to a Me2SO solution of [Fe(0-Me2S0)6P+ causes a change in spectrum, but further additions have no effect. Comparisons with known compounds indicate that [Fe(0-Me2S0)5Cip+ is the major species in solution. 

Phthalocyaninato(2-)] iron(II) is a dark blue, thermally stable solid that can be sublimed in vacuo at 300°. It is very soluble in pyridine, giving deep blue solutions of the bis(pyridine) adducts. It also forms an unstable purple hexaaniline adduct when dissolved in aniline. It is soluble in concentrated sulfuric add and dimethyl sulfoxide (slightly) but is insoluble in most other organic solvents. The iron(II) complex, unlike the corresponding iron(II) porphines, is relatively stable toward oxidation to the iron (III) state. The electronic spectrum shows the following absorption bands (1-chloronaphthalene solution) 595 (e = 16,000), 630 (e = 17,000), 658 (e = 63,000) (pyridine solution) 333 (e = 45,000), 415 (e = 15,000), 395 (e = 2000), 658 nm (e = 8000). 

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