In situ X-ray Measurements to Probe a New Solid-State Polycondensation Mechanism for the Design of Supramolecular Organo-Bridged Silsesquioxanes

Philippe Dieudonné (1) , Michel Wong Chi Man (2) , Benoît P. Pichon (2) , Luc Vellutini (2) , Jean-Louis Bantignies (1) , Christophe Blanc (1) , Gaëlle Creff (1) , Stéphanie Finet (3) , Jean-Louis Sauvajol (1) , Catherine Bied (2) , Joël J.E. Moreau (2)

1 LCVN - Laboratoire des colloïdes, verres et nanomatériaux
2 ICGM ICMMM - Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier
3 ESRF - European Synchrotron Radiation Facility

A long-range ordered organic/inorganic material is synthesized from a bissilane, (EtO)3Si–(CH2)3–NHCONH–C6H4–NHCONH–(CH2)3–Si(OEt)3. This crosslinked sol–gel solid exhibits a supramolecular organization via intermolecular hydrogen bonding interactions between urea groups (–NHCONH–) and covalent siloxane bonding, Si–O–Si . Time-resolved in situ X-ray measurements (coupling small- and wide-angle X-ray scattering techniques) are performed to follow the different steps involved in the synthetic process. A new mechanism based on the crystallization of the hydrolyzed species followed by their polycondensation in solid state is proposed.

Mots clés: SAXS; silsequioxanes; sol–gel materials; solid-state reactions; reaction mechanisms; WAXS

Domaines: Chimie organique

Philippe Dieudonné, Michel Wong Chi Man, Benoît P. Pichon, Luc Vellutini, Jean-Louis Bantignies, et al.. In situ X-ray Measurements to Probe a New Solid-State Polycondensation Mechanism for the Design of Supramolecular Organo-Bridged Silsesquioxanes. Small, 2009, 5 (4), pp.503-510. ⟨10.1002/smll.200800254⟩. ⟨hal-00381858⟩