SOLUBLE SUBSTITUTED MU-OXO(PHTHALOCYANINATO)IRON(III) DIMERS

Attempts to prepare various peripheral tetra- and octasubstituted (pht halocyaninato)iron derivatives R(n)PcFe [n = 4: R CH(2)OEt (6e), CO(2) Et (6h), CO2-n-C6H13 (6i), O(2-Et-n-C6H13) (6j), OCH2C(CH3)(3) (6k), O CH2C(CH3)(2)CH(2)Ph (61); n = 8: R = CH2CH(CO(2)Me)CH(CO(2)Me)CH2 (6f) , CH2CH(CO(2)Et)CH(CO(2)Et)CH2 (6g), O-n-C8H17 (6m), O(2-Et-n-C6H13) ( 6n)] by starting from the corresponding substituted phthalonitriles le d to substituted (mu-oxo)bis[(phthalocyaninato)iron(III)] compounds [R (n)PcFe]O-2. The terl-butyl- and ethyl-substituted systems [tBu(4)PcFe ]O-2 (6c) and [Et(4)PcFe]O-2 (6d) were reinvestigated. UV/Vis, FD mass , Mossbauer, NMR as well as ESR spectroscopy was used to characterize the complexes [R(n)PcFe]O-2 to furnish evidence for the presence of Fe -O-Fe moieties in [R,PcFe]O-2. The UV/Vis data reported for [R(n)PcFe] O-2 as well as their spectral behavior in pyridine correspond to unsub stituted [PcFe]O-2. Mossbauer spectra of [R(n)PcFe]O-2 show that the c omplexes were obtained as a mixture of two isomeric mu-oxo compounds A (delta(Fe) = 0.22 mm s(-1) Delta E(Q) = 1.33-1.39 mm s(-1)) and B (de lta(Fe) = 0.33-0.36 mm s(-1) Delta E(Q) = 0.39-0.53 mm s(-1)), whose M ossbauer parameters are comparable to [PcFe]O-2 mu-oxo(2) and mu-oxo(1 ), respectively. Mossbauer spectral data of [R(n)PcFe]O-2 indicate hig h-spin (S = 5/2) Fem centers. NMR-spectra of [R(n)PcFe]O-2 (n = 4: R = tBu, Et, O(2-Et-n-C6H13), OCH2C(CH3)(2)CH(2)Ph; n = 8: R = O-n-C8H17, O(2-Et-n-C6H13) give further evidence for mu-oxo bridged structures.