Vibrational spectra of silsesquioxanes impregnated with the metallocene catalyst bis(eta(5)-cyclopentadienyl)zirconium(IV) dichloride

Spectrochim Acta A Mol Biomol Spectrosc. 2007 Nov;68(3):956-69. doi: 10.1016/j.saa.2007.01.009. Epub 2007 Jan 19.

Abstract

FT-IR photoacoustic and Raman spectroscopy have been used to study the interactions between the metallocene catalyst, Cp(2)ZrCl(2) (Cp=eta(5)-C(5)H(5)), and two polyhedral oligomeric silsesquioxanes (POSS) supports. The first silsesquioxane support, POSS(h), contains (beta-hydroxyl)-tertiary amine groups, while in the second one, POSS(u), these -OH groups have been converted into N-(p-toluyl) urethane groups. The vibrational spectra of the Cp(2)ZrCl(2):POSS(h) and Cp(2)ZrCl(2):POSS(u) samples show that the Cp(2)ZrCl(2) catalyst reacts with the C-OH groups of POSS(h) and also interacts with N-H and >CO groups of POSS(u). Furthermore, Cp(2)ZrCl(2) can react with the Si-OH groups of the POSS supports and also interact with the O atoms that are bonded to the benzene rings and the N atoms of the tertiary amines in both silsesquioxanes. As a result of the interactions between Cp(2)ZrCl(2) and the POSS supports, acidic species are generated. The Cp(2)ZrCl(2):POSS(h) mass ratio seems to be an important parameter in the formation of Zr-O bonds and the acidic species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Organometallic Compounds / chemistry*
  • Organosilicon Compounds / chemistry*
  • Spectrum Analysis, Raman*
  • Urethane / chemistry
  • Vibration*
  • Zirconium / chemistry*

Substances

  • Organometallic Compounds
  • Organosilicon Compounds
  • bis(eta(5)-cyclopentadienyl)zirconium(IV) dichloride
  • metallocene
  • Urethane
  • Zirconium