Consequences of Electron-Density Manipulations on the X‑ray Photoelectron Spectroscopic Properties of Ferrocenyl-β-diketonato Complexes of Manganese(III). Structure of [Mn(FcCOCHCOCH3)3]

Reaction of [Mn3(OAc)6O·3H2O]+ (1) with ferrocenyl β-diketones of the type FcCOCH2COR with R = CF3 (2a) and CH3 (2b), Ph = C6H5 (2c), and Fc = FeII(η5-C5H4)­(η5-C5H5) (2d) yielded a series of ferrocene-functionalized β-diketonato manganese­(III) complexes 3a–3d, respectively, of general formula [Mn­(FcCOCHCOR)3]. The mixed-ligand β-diketonato complex [Mn­(FcCOCHCOFc)2(FcCOCHCOCH3)] (4) was obtained by reacting mixtures of diketones 2b and 2d with 1. A single-crystal X-ray structure determination of 3b (Z = 2, triclinic, space group P1̅) highlighted a weak axial elongating Jahn–Teller effect and a high degree of bond conjugation. An X-ray photoelectron spectroscopic study, by virtue of linear relationships between group electronegativities of ligand R groups, χR, or ∑χR, and binding energies of both the Fe 2p3/2 and Mn 2p3/2 photoelectron lines, confirmed communication between molecular fragments of 2a–2d as well as 3a–3d. This unprecedented observation allows prediction of binding energies from known β-diketonato side group χR values.