Two from one: It is possible to form two different, interpenetrating polymer structures—silicon dioxide and a phenolic resin—simultaneously in a single step without the formation of by‐products by using a readily polymerizable, organic silicon spiro compound. This new polymerization process enables the fabrication of materials with domain sizes of 0.5 to 3 nm.

Aus eins mach zwei: Ausgehend von einer leicht polymerisierbaren Silicium‐Spiroverbindung gelingt es, in einem einzelnen Prozessschritt zwei interpenetrierende Polymerstrukturen – SiO2 und Phenolharz – ohne die Bildung von Beiprodukten herzustellen. Diese neue Polymerisationsmethode ist auf verschiedenste Monomere anwendbar und macht Polymermaterialien mit Domänengrößen von 0.5 bis 3 nm zugänglich.

No abstract

Nanosized titanium dioxide is of importance as a photocatalyst, as pigment, and, for example for photovoltaic applications because of its electronic, optoelectronic, and catalytic properties.[1] The most convenient synthetic route is the hydrolytic sol-gel process which allows titanium oxides and/or its precursors to be produced in a straightforward way from titanium alkoxides by hydrolysis and condensation at low temperature. [2][3][4][5] This synthetic methodology has a widespread applicability and is well documented. [2][3][4][5] The sol-gel approach requires water addition for the hydrolysis process and hence, the formation of by-products (e.g., alcohols) and the associated formation of a gel, which undergoes substantial shrinkage on drying, is observed. However, nonaqueous synthetic routes allow the control of the shape, size, and crystallinity of metal oxides and in addition, are readily to handle, compared to convenient sol-gel processes. [6][7][8][9] The main limitation of this concept is the insufficient solubility of some metal halides in nonaqueous solvents. In this work we present a new concept for the synthesis of titanium dioxide starting from cationically polymerizable titanium monomers. The so called ''Twin-Polymerization'' strategy [10] allows the reaction of hybrid monomers in organic solvents or in melt without admitting water. The formation of the polymer is associated with that of the inorganic compound. Thus, it is possible to synthesize interpenetrating inorganic/ polymer composite materials. We report here on the synthesis and cationic polymerization of a titanium hybrid monomer which undergoes polymerization to a poly(furfuryl alcohol)/ titanium oxide nanocomposite material. The titanium oxide component can be obtained after removing of the organic polymer out of the composite.(m 4 -Oxido)-hexakis(m-furfuryloxo)-octakis(furfuryloxo)-tetra-titanium (I) is readily accessible by the transesterification of tetraethyl orthotitanate with furfuryl alcohol (Scheme 1). Madaliev et al. described a similar reaction of tetra-tert-butyl orthotitanate and furfuryl alcohol, in order to obtain tetra-furfuryl orthotitanate.[11] The product was characterized by quantitative elemental analysis, bromine number, and saponification value.[11]Excess of furfuryl alcohol and ethanol (formed during the reaction) were removed by distillation from the reaction mixture containing one equivalent of tetraethyl orthotitanate and 4.05 equiv. of furfuryl alcohol, whereby the resulting brown liquid solidified at room temperature. Moisturesensitive crystals of I suitable for single crystal X-ray structure analysis were obtained from a mixture of toluene/n-hexane (1:1 v v À1) at room temperature. The structural analysis reveals that I exists in the solid state as a novel tetrameric titaniumoxo-cluster containing a Ti 4 (m 4 -O) core, cf. Figure 1. Oxoclusters containing the Ti 4 (m 4 -O) core are very rare, so far only two related clusters have been described, [12,13] possessing;however, a further m-bridging oxido (O 2À ) li...

A third twin: Homopolymers are formed by the copolymerization of two twin monomers. Using the new method of simultaneous twin polymerization, complex hybrid materials can be synthesized in a targeted manner (see scheme), in which, depending upon the combination of twin monomers used, nanostructured hybrid materials with different compositions and properties can be obtained.