engleski

The nature of metal-ligand bonding in ferrocenes by empirical analysis

HeI and HeII UV photoelectron spectra (UPS) of 1-cyanomethyl, 1-butyryl and 1, 1'-bis(dimethylsilyl)-ferrocene were measured. A new approach to the study of metal-ligand bonding is described which relies on the correlation analysis of experimental descriptors appropriate to ligand and metal orbitals rather than on various theoretical models and calculations. Metal and ligand ionization energies correlate better with  p than  m constants indicating that both inductive and resonance effects should be considered, i.e. that Fe-Cp interactions are not exclusively of Fe  Cp  -back-donation type bonding.1 It is consistent with the DFT calculations results based on the B3LYP hybrid functional which claimed that metal-ligand bonding in ferrocene must include ionic (electrostatic) contribution from Fe2+ and (Cp-)2 fragments. 2 Nevertheless, due to the inevitable dependence of theoretical results on model Hamiltonian and basis sets it is of considerable importance to independently substantiate theoretical claims by experimentally derived quantities

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