A combined spectroscopic and theoretical study of dibutyltin diacetate and dilaurate in supercritical CO2
CLOUTET, Eric
Laboratoire de Chimie des polymères organiques [LCPO]
Team 4 LCPO : Polymer Materials for Electronic, Energy, Information and Communication Technologies
Laboratoire de Chimie des polymères organiques [LCPO]
Team 4 LCPO : Polymer Materials for Electronic, Energy, Information and Communication Technologies
CRAMAIL, Henri
Laboratoire de Chimie des polymères organiques [LCPO]
Team 2 LCPO : Biopolymers & Bio-sourced Polymers
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Laboratoire de Chimie des polymères organiques [LCPO]
Team 2 LCPO : Biopolymers & Bio-sourced Polymers
CLOUTET, Eric
Laboratoire de Chimie des polymères organiques [LCPO]
Team 4 LCPO : Polymer Materials for Electronic, Energy, Information and Communication Technologies
Laboratoire de Chimie des polymères organiques [LCPO]
Team 4 LCPO : Polymer Materials for Electronic, Energy, Information and Communication Technologies
CRAMAIL, Henri
Laboratoire de Chimie des polymères organiques [LCPO]
Team 2 LCPO : Biopolymers & Bio-sourced Polymers
< Réduire
Laboratoire de Chimie des polymères organiques [LCPO]
Team 2 LCPO : Biopolymers & Bio-sourced Polymers
Langue
en
Article de revue
Ce document a été publié dans
Journal of Physical Chemistry A. 2008, vol. 112, n° 36, p. 8379-8386
American Chemical Society
Résumé en anglais
Two organotin catalysts, namely, dibutyltin dilaurate (DBTDL) and dibutyltin diacetate (DBTDA), commonly used in the synthesis of polyurethanes, have been investigated combining vibrational spectroscopic measurements with ...Lire la suite >
Two organotin catalysts, namely, dibutyltin dilaurate (DBTDL) and dibutyltin diacetate (DBTDA), commonly used in the synthesis of polyurethanes, have been investigated combining vibrational spectroscopic measurements with molecular modeling. The structure and vibrational spectra of the DBTDA molecule have been simulated using density functional theory. Thus, because of the Sn center dot center dot center dot O interactions, the lowest energy conformer reveals an asymmetrically chelated structure of the acetate groups with a C-2u symmetry. The experimental IR spectra of DBTDA and DBTDL diluted in carbon tetrachloride and in supercritical CO2 show unambiguously that these molecules adopt the asymmetrically chelated conformation in the solvent. A new attribution of the main peaks constituting the respective IR spectra of the catalysts could be carried out. Finally, from the IR spectra of the two catalysts diluted in supercritical CO2 reported as a function of time, it was found that both molecules react slightly with CO2. However, their spectrum remains unchanged at the earliest stage of the polymerization, indicating that these molecules preserve a catalytic activity similar to that noted in conventional organic solvent.< Réduire
Mots clés en anglais
CARBOXYLIC-ACIDS
URETHANE FORMATION
EPSILON-CAPROLACTONE
ORGANOTIN COMPOUNDS
RING-OPENING POLYMERIZATION
CARBON-DIOXIDE
AB-INITIO
VIBRATIONAL FREQUENCIES
CATALYTIC MECHANISMS
DENSITY
Origine
Importé de halUnités de recherche