Activated (Ph3P)(3)RuH2CO (Ru) catalyzed copolymerization of 1,4-bis(5＇-acetyl-2＇-thienyl)benzene (I) and 1,3-divinyltetramethyldisiloxane (II) yields alt-copoly[3,3,5,5-tetramethyl-4-oxa-3,5-disila-1,7-heptanylene/2＇,2"-diacetyl-5＇,5"-(1,4-benzene)-3＇,3"-bis(thiophenylene)] (III). On the other hand, Ru catalyzed copolymerization of 1,3-bis(5＇-acetyl-2＇-thienyl)benzene (IV) and II fails. Nevertheless, Ru catalyzed reaction of IV with excess vinylpentamethyldisiloxane (V) yields 1,3-bis(4＇-pentamethyldisiloxy-ethyl-5＇-acetyl-2＇-thienyl)benzene (VI). VI undergoes acid catalyzed siloxane equilibration polymerization to give alt-copoly[3,3,5,5-tetramethyl-4-oxa-3,5-disila-1,7-heptanylene/2＇,2"-diacetyl-5＇,5"-(1,3-benzene)-3＇,3"-bis(thiophenylene)] (VIT) and hexamethyldisiloxane. Copolymers III and VII have been characterized.