Time-dependent density functional theory simulation of UV/visible absorption spectra of zirconocene catalysts

The UV/visible absorption spectra of rac-Et(Ind)2ZrCl2, rac-Et(Ind)2ZrMeCl, rac-Et(Ind)2Zr(Me)2, and the [rac-Et(Ind)2ZrMe–C2H4]+ complex, have been simulated by using the TDDFT technique within the adiabatic approximation and by using several basis sets and XC functionals. Hybrid XC functionals (B3LYP, B3P86 and mPW1PW91) turn out to reproduce fairly well the essential features of the experimental spectra which originate from ligand to metal charge transfer transitions. The comparison between the simulated and recorded UV/visible absorption spectra appears therefore as a promising technique for assigning the structure of reaction intermediates in zirconocene polymerization.