NEW MATERIAL:A compound shown by formula I [R is (substituted) monofunctional hydrocarbon; Y is hydrolyzable group selected from halogen, alkoxy and aryloxy].

EXAMPLE: 1,3-Bis(trichlorosilyl)-2-methylpropane.

USE: For improving adhesiveness, reliability, mechanical characteristics, electrical characteristics, water resistance and water vapor resistance of organic-inorganic composite material such as semiconductor sealing material, etc., and reducing cost by adding a large amount of inorganic filler.

PREPARATION: 3-Chloro-2-chloromethylpropene shown by formula II is made to react with a hydrohalogenosilane compound shown by formula III (X is halogen) in the presence of a catalytic amount of a copper compound by using a tertiary amine as a hydrogen chloride scavenger to give a compound shown by formula I wherein group Y is halogen.