Crystal and molecular structure of 2a,3,4,5,6,7,8,8b-octafluoro-2-methyl-2-(2-methylprop-1-enyl)-1,2,2a,8b-tetrahydrocyclobuta[a]napthalene

The title compound (3) is monoclinic, space group P21/c, a= 12.006(10), b= 28.532(20), c= 8.993(10)Å, β= 90.10(10)°, Z= 8. The structure was solved from diffractometer data by direct methods and refined to R 0.07 for 2 399 observed reflexions. The two independent molecules in the asymmetric unit exhibit no major structural differences. There is evidence for stacking of aromatic rings.