4,8-Ethenobenzo[1,2-c:4,5-c′]dipyrrolium, 2,2,6,6-tetraethyl-1,2,3,3a,4,4a,5,6,7,7a,8,8a-dodecahydro-, (3aα,4β,4aα,7aα,8β,8aα)- (ACI)