XPS and Their Valence Band Spectra Studies of the substituted Titanocene, Zirconocene and Hafnocene Dichloride Complexes

This paper reports a detailed XPS and their valence hand spectra studies for the substitution of alkyl for hydrogens on the cyclopentadienyl ligand. It have been shown that the substituted of CH₃, C₂H₅, C₃H₇, C₅H₁₁, C₆H₁₁ on the cyclopentadienyl ligand result in a dramatic electronic effect. The relation between the ditermined "Ionization energy" from the lowest ionization energy peak of XPS valence band spectra and the various substitutive groups of the cyclopentatienyl ligand is discussed. And then it have also shown that XPS valence band spectra of the different trasition metal element compounds are their character of the metal elements. We have found that the intensity of third peak near 25eV ionization energy increase obviously in their XPS valence band spectra of the substituted titanocenes, this reflects the relativity increased weight of methyl in the ligand.