• Bulletin of the Korean Chemical Society
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• v.28 no.8
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• pp.1305-1310
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• 2007

A conjugated spirocyclic polymer was synthesized via the cyclopolymerization of 1,1-dipropargyl-1- silacyclohexane with various transition metal catalysts. The monomer, 1,1-dipropargyl-1-silacyclohexane was synthesized by Grignard reaction of 1,1-dichloro-1-silacyclohexane with propargyl magnesium bromide. This polymerization proceeded well to give the corresponding poly(1,1-dipropargyl-1-silacyclohexane). The catalytic activity of WCl6 was found to be similar with that of MoCl5. The structure of polymer having the conjugated backbone with silacyclohexane moieties was characterized by such instrumental methods as NMR (1H-, 13C-), IR, and UV-visible spectroscopies. The resulting polymers were mostly yellow or light-brown powders, depending on the catalyst systems used. This polymer was completely soluble in halogenated and aromatic hydrocarbons such as chloroform, 1,2-dichloromethane, benzene, toluene, and chlorobenzene, etc. The thermal and oxidative stabilities of polymer were also studied and discussed.

• Bulletin of the Korean Chemical Society
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• v.21 no.8
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• pp.793-796
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• 2000

In the neat flow vacuum pyrolysis of 2-methoxy-2-(o-N,N+dimethylaminomethyl)phenyl-3-trimethylsilyl-5,5-dime-thyl-2-silahexane (4) at $600^{\circ}C$ and its static thermolysis at $350^{\circ}C23-benzo-5-aza-1-silacyclohexane$, (5) has been obtained in97% and 46％ y ields, respectively. Product 5 might have been formed via an intramolecular rearrangement invoIving a zwitterionic species generated from the pentacoordinated silene Si-atom. From trapping experiments with an excess of MeOH, we have obtained 2-(o-N,N-dimethylaminomethyl)phenyl-5,5-dimethyl-2-trimethylsiloxy-2-silahexane (6) and 2-(o-N,N-dimethylaminomethyl)phenyl-2-methoxy-5,5-dime-thyl-2-silahexane (7) formed via an intermolecular protodesilylation reaction rather than through trapped prod-ucts of the silene.