Twin Polymerization using metal alkoxides -  a nonaqueous synthetic route for metal oxide-based
hybrid materials


Prof. Dr. Michael Mehring

Technische Universität Chemnitz

Institut für Chemie


Abstract

Organic-inorganic hybrid materials with high porosity, well defined and nanoscaled pore geometry,
and monodisperse domain size distribution are currently an active field of research. Materials with
domain sizes in the range between 3 to 100 nm are accessible by several synthetic concepts, whereas
smaller domain sizes are difficult to address. A novel concept, the so-called Twin Polymerization
(TP), is based on nonaqueous synthetic processes and gives access to domain sizes below 3 nm for
metal oxide based organic-inorganic composites. For example, Twin Polymerization of
2,2’-Spirobi[4H-1,3,2-benzodioxasiline] provides a composite material composed of interpenetrating
SiO[2]/Phenol resin networks with defined nanostructured domains of 0.5 to 3 nm. Oxidation of this
composite material provides highly porous SiO[2], while carbonization and consecutive removal of
SiO[2 ]gives microporous carbon. This modular approach also gives access to metal oxide
nanoparticles. Here, the synthesis and reaction behavior of diverse novel monomers including main
group elements such as Si, Ge, Sn, Bi, In etc. is presented and their use with regard to Twin
Polymerization and the related Simultaneous Twin Polymerization will be focused on. The as-prepared
organic-inorganic composite materials and metal oxide nanoparticles were characterized with focus
on structure and properties such as porosity, pore size distribution and particle size. In order to
support our hypothesis of a reactivity scale of the monomers DFT calculations accompany the
experiments in order to obtain a more detailed insight into the first reaction steps of this novel
type of synthetic route for organic-inorganic hybrid materials.


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Schaarschmidt, H. Lang, N. Jöhrmann, M. Hietschold, F. Simon, M. Mehring, ChemPlusChem 2013, DOI:
10.1002/cplu.201200242