Synthesis and Mossbauer spectroscopic studies of chemically oxidized ferrocenyl(phenyl)phosphines.

摘要: The electrochemical potentials of Fc3-xPPhx, (1-3, x = 0-2) and (FcPPh)n (4) indicate that iodine should oxidize ferrocenyl(phenyl)phosphines. molar conductivity solutions 1-3 increases sharply when the are titrated with iodine, leveling off after addition > 2 equiv oxidant, consistent formation 1:1 electrolytes. Diamagnetic salts 6-9 observed upon a benzene solution to 1-4 at ambient temperature in ratios I2/metallocene ranging from 2:1. Well-resolved 1H 31P NMR spectra obtained for 6-8. Absorptions assigned I3- anion dominate UV-vis spectrum 6-8, whereas characteristic absorptions [Fc][I3] absent. Mossbauer 7-9 reveal isomer shifts low-spin iron(II) ferrocene derivatives rather than those ferricenium ions. Small amounts FeIII appear be present 6. Taken together, results suggest iodophosphonium not salts. Diferrocenyl(phenyl)phosphine oxide (5) reacts produce diamagnetic, dark solid 10. Low-spin FeII is 77 293 K 10 no evidence oxidation FeIII. Compound proposed neutral complex between 5 I2. Reactions 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) yield [Fc2P(=O)][DDQ]2 (11). spectroscopy 11 indicates presence mixture K, suggesting some electron transfer occurs DDQ. fraction room temperature.