1,1'-(E)-ethene-1,2-diylbis(3,4-dimethoxybenzene) InChI=1/C18H20O4/c1-19-15-9-7-13(11-17(15)21-3)5-6-14-8-10-16(20-2)18(12-14)22-4/h5-12H,1-4H3/b6-5 benzene, 1,1'-[(E)-1,2-ethenediyl]bis[3,4-dimethoxy-