Vibrational spectra of silsesquioxanes impregnated with the metallocene catalyst bis(eta(5)-cyclopentadienyl)zirconium(IV) dichloride.
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.
Bianchini
D
D
McGill University, Department of Chemistry, Montréal, Québec, Canada.
Barsan
M M
MM
Butler
I S
IS
Galland
G B
GB
dos Santos
J H Z
JH
Fasce
D P
DP
Williams
R J J
RJ
Quijada
R
R
D002384:Catalysis; D009942:Organometallic Compounds / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D014520:Urethane / Q000737:chemistry; D014732:Vibration; D015040:Zirconium / Q000737:chemistry*
D009942:Organometallic Compounds; D017646:Organosilicon Compounds; C526672:bis(eta(5)-cyclopentadienyl)zirconium(IV) dichloride; C013108:metallocene; D014520:Urethane; D015040:Zirconium