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 [Mn-3(OAc)(6)O center dot 3H(2)O](+) (1) with ferrocenyl beta-diketones of the type FcCOCH(2)COR with R = CF3 (2a) and CH3 (2b), Ph = C6H5 (2c), and Fc = Fe-II(eta(5)-C5H4)(eta(5)-C5H5) (2d) yielded a series of ferrocene-functionalized beta-diketonato manganese(III) complexes 3a-3d, respectively, of general formula [Mn(FcCOCHCOR)(3)]. The mixed-ligand beta-diketonato complex [Mn(FcCOCHCOFc)(2)(FcCOCHCOCH(3))] (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 P (1) over bar) 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, chi(R), or Sigma chi(R), and binding energies of both the Fe 2p(3/2) and Mn 2p(3/2) 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 beta-diketonato side group chi(R) values.