TRIS(2,4-PENTANEDIONATO)VANADIUM-CATALYZED CYCLOTRIMERIZATION AND POLYMERIZATION OF 4-(N,N-DIMETHYLAMINO)PHENYLETHYNE - X-RAY STRUCTURE OF 1,2,4-TRIS[4-(N,N-DIMETHYLAMINO)PHENYL]BENZENE

Tris(pentane-2,4-dionato)vanadium-catalysed polymerization of 4-(N,N-d imethylamino)phenylethyne gave a polyene with pi-conjugated donor subs tituents. Similarly, cyclotrimerization of the acetylene derivative ga ve a mixture of 1,2,4- and 1,3,5-tris[4-(N,N-dimethylamino)phenyl]benz ene in variable yield, depending on the reaction conditions employed. The molecular structure of the main 1,2,4- isomer was determined by X- ray diffraction methods.