Japan Science and Technology Agency

Chinese Academy of Sciences

Caihong Xu

Shigehiro Yamaguchi

Yongming Li

Kohei Tamao

Lijuan He

Xiaogan Yang

This invention provides a method for preparing a polycarbosilane by decomposition and rearrangement a cyclic silane compound or chain polysilane under the catalysis of a boron-containing catalyst in a trace amount (less than 1 wt %). In the method, poly(dimethylsilane) (denoted as PDMS) or a thermal decomposition product thereof, i.e., a liquid silane-carbosilane compound (denoted as LPS), is used as the raw material, less than 1 wt % of the boron-containing catalyst (with respect to the amount of the raw material) is added, and then the temperature is gradually increased to the reaction temperature under atmospheric pressure or high pressure to perform the thermal decomposition/rearrangement reaction so as to obtain solid polycarbosilane (PCS) with a higher ceramic yield. This method has advantages, such as short reaction time, high synthetic yield, good product quality, simple equipment and safe operation; and the polycarbosilane prepared is a polymeric precursor for SiC, and can be used for the preparation of SiC fibers and SiC-based composite materials.

Method for preparing polycarbosilane by catalytic rearranging

A polycyclic fused ring type &#x3c0;-conjugated organic material (VIIa, VIIb, VIIc, VIId) is obtained in the following manner. That is, as shown in Scheme 1 below, a starting material (I) is dimetalated with an organometallic base. The starting material (I) thus dimetalated is trapped with an organosilicon reagent (i: (1) n-BuLi or t-BuLi; (2) HMeSiCl). As a result, an intermediate is obtained. Thereafter, the intermediate is allowed to react with a metal reductant. This causes an intramolecular reductive cyclization reaction to proceed. As a result, a dianion intermediate is produced. The dianion intermediate is trapped with an electrophile (ii: (1) LiNaph, THF, rt, 5 min; (2) electrophile or NHCl) In this way, the polycyclic fused ring type &#x3c0;-conjugated organic material is obtained. The polycyclic fused ring type &#x3c0;-conjugated organic material, an intermediate therefor, a method for producing the polycyclic fused ring type &#x3c0;-conjugated organic material, and a method for producing the intermediate make it possible to provide a polycyclic fused ring type &#x3c0;-conjugated organic material having excellent light-emitting and charge-transporting properties.

Polycyclic fused ring type &#x3c0;-conjugated organic material, intermediate therefor, process for producing polycyclic fused ring type &#x3c0;-conjugated organic material, and process for producing intermediate of polycyclic fused ring type &#x3c0;-conjugated organic material

The invention provides condensed polycyclic &#x3c0;-conjugated organic materials and manufacturing methods for the materials. A metal reducing agent is reacted with a straight-chain, triple bond-containing hydrocarbon (aryl acetylene compound, phenyl acetylene compound), the hydrocarbon being a benzene ring with an organic silicon as a substituent, so as to allow an intramolecular reductive cyclization reaction to proceed between the silicon and the triple-bond carbon. The reaction produces condensed polycyclic &#x3c0;-conjugated organic materials of the invention. The invention provides light-emitting materials applicable for organic electroluminescent devices, condensed polycyclic &#x3c0;-conjugated organic materials applicable for charge transport materials, their intermediate products, and a manufacture method for condensed polycyclic &#x3c0;-conjugated organic materials.

Condensed polycyclic &#x3c0;-conjugated organic material, intermediate product therefor, and method of manufacturing condensed polycyclic &#x3c0;-conjugated organic material

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Beijing, China

Caihong Xu