Infrared and ultraviolet–visible spectroscopic studies on manganese heptoxide (Mn2O7)

Abstract

Infrared and u.v.–visible spectra are reported for Mn₂O₇ both in the solid phase and as a monomeric species isolated in low-temperature matrices. The i.r, spectra are consistent with the expected bridged structure, and indicate a relatively wide O₃Mn–O–MnO₃ angle. Characteristic i.r. absorptions are found at ca. 955 cm^–1[ν_asym(MnO)], ca. 890 cm^–1[ν_sym(MnO)], and ca. 775 cm^–1[ν_asym(Mn–O)]. The electronic spectrum of Mn₂O₇ shows a number of charge-transfer bands with partially resolved vibrational progressions, and their features are compared with those of related manganese(VII) oxo-species.