Study of the electronic structure of polynuclear cobalt trimethylacetate complexes by Co3s and Co3p X-ray photoelectron spectroscopy

The electronic structure of mono-, hexa-, and nonanuclear cobalt trimethylacetate complexes was studied by XPS. The Co3s- and Co3p X-ray photoelectron spectra of the complexes were recorded. The Co3p spectrum of bivalent cobalt was calculated in the isolated-ion intermediate-coupling approximation. Spectrum analysis showed that the [Co(N-Phobsqdi)2(η′-N-Ph-opda)(OOCCMe3)] complex is a strong-field complex with Co(III) in the diamagnetic state; the [Co(dipy)2(OOCCMe3)2], [Co(dipyam)(OOCCMe3)2], and [Co9(μ3-OH)6(μ-OOCCMe3)12(OCMe2)4] are high-spin weak-field Co(II) complexes; and the [Co6(μ4-O)2(OOCCMe3)10(THF)4] complex contains both the Co(II) and Co(III) atoms. The energy position of major Co3s- and Co3p spectral maxima were found to be sensitive to the nature of the nearest environment of cobalt atoms. The data correlate well with X-ray crystallographic data.