Bicyclo[2.2.1]heptane-2,3-dicarbothioic acid,5-[(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-heptadecafluorodecyl)thio]-,S,S-dihexyl ester, (2-exo,3-endo,5-exo)-