Trisilane,1,3-bis[5'-[(1,1-dimethylethyl)dimethylsilyl][2,2'-bithiophen]-5-yl]-2-[[5'-[(1,1-dimethylethyl)dimethylsilyl][2,2'-bithiophen]-5-yl]dimethylsilyl]-1,1,2,3,3-pentamethyl-