1,3,5-cycloheptatriene, 7-(2,4-cyclopentadien-1-ylidene)- 7-cyclopenta-2,4-dien-1-ylidenecyclohepta-1,3,5-triene InChI=1/C12H10/c1-2-4-8-11(7-3-1)12-9-5-6-10-12/h1-10