ORIGINAL PAPER Hydridosilazanes hydrolysis-condensation reactions studied by 1 H and 29 Si liquid NMR spectroscopy Nicolas Darge `re • Ve ´ronique Bounor-Legare ´ • Fernande Boisson • Philippe Cassagnau • Gre ´gory Martin • Phillipe Sonntag • Nicolas Garois Received: 13 October 2011 / Accepted: 5 March 2012 / Published online: 21 March 2012 Ó Springer Science+Business Media, LLC 2012 Abstract Hydridosilazane compounds containing Si–N and Si–H bonds can be used as precursors of SiO x mate- rials. The hydrolysis-condensation reactions of tetrameth- yldisilazane, as a polyhydridosilazane model compound, were investigated by 1 H and 29 Si liquid NMR spectros- copy. These reactions were carried out at room temperature for up to 120 min in presence of water. The identified products are short linear siloxane species (hydride termi- nated polydimethylsiloxanes M H D x M H ) and cyclosilox- anes. Silicon hydride persistence in the reactional mixture suggested that silazane group is more sensitive to hydro- lysis reaction than silicon hydride group. Moreover, addi- tional experiments evidenced that the low steric hindrance of the silicon hydride influences the silazane hydrolysis kinetic. Hence the presence of ammonia released during silazane hydrolysis reaction was demonstrated to be a catalyst of the silicon hydride hydrolysis reaction. Keywords Hydridosilazane Á Hydrolysis-condensation reaction Á Liquid NMR 1 Introduction Thermal treatment of polysilazane polymers based on Si–N–Si backbone have been classically used for the prep- aration of SiN, SiCN, or SiOCN ceramic materials [1–4]. In particular polyhydridosilazane compounds containing mainly Si–N and Si–H moieties can lead to the formation of SiO x materials through several type of treatments such as Ultra Violet (UV) irradiation [5–8], thermal treatment [9, 10] or hydrolysis and condensation reactions [11–16] at room temperature or temperatures below 100 °C. In the case of silazane treatment by UV irradiation, conversion of Si–N into Si–O onto a surface is achieved by Vacuum Ultra Violet in presence of air [5], ozone [6], O 2 [7], or atomic oxygen [8]. Without water, Si–N decompo- sition only depends on the UV dose and the presence of tertiary amine as oxygen transfer catalyst [6]. As thermal treatment is concerned, amorphous silica was synthesized by polysilazane heating in air at 600 °C during 10 h. In that case nitrogen and hydrogen of the silazane precursor are fully substituted by oxygen [9]. Gunthner et al. [4] inves- tigated this degree of substitution for perhydropolysilazane (PHPS) and evidenced that the atomic composition of the final product depends on the nature of the curing atmo- sphere (air or nitrogen). However the PHPS to silica con- version in their conditions is not complete and the residual nitrogen content is around 12 wt%. Polysilazane films were also exposed to several vapor phases. Kubo et al. [11] used the Fourier Transform InfraRed spectroscopy (FTIR) to study at room temperature the influence of various acidic and basic water solutions onto the PHPS to silica conversion. The highest degrees of conversion were obtained with alkaline aqueous solutions. These authors studied also the influence of aqueous ammonia concentration onto the PHPS to silica conversion N. Darge `re Á V. Bounor-Legare ´(&) Á P. Cassagnau CNRS, UMR 5223 IMP@Lyon1, Universite ´ de Lyon, 15 Boulevard Latarjet, 69622 Villeurbanne Cedex, France e-mail: veronique.bounor-legare@univ-lyon1.fr N. Darge `re Á G. Martin Á P. Sonntag Hutchinson S.A., Centre de Recherche, Rue Gustave Nourry, 45120 Chalette Sur Loing, France F. Boisson CNRS, INSA-Lyon, IMP/Service de RMN des Polyme `res, UMR5223, Universite ´ de Lyon, 69621 Villeurbanne, France N. Garois Hutchinson Polymers, Parc d’Activite ´s d’Arboria, 55 Rue des Platanes, 45700 Pannes, France 123 J Sol-Gel Sci Technol (2012) 62:389–396 DOI 10.1007/s10971-012-2738-2