2,2'(1H,1'H)-spirobi[s-indacene], 4,4'-diethyl-3,3',5,5',6,6',7,7'-octahydro- 4,4'-diethyl-3,3',5,5',6,6',7,7'-octahydro-1H,1'H-2,2'-spirobi[s-indacene] InChI=1/C27H32/c1-3-21-23-9-5-7-17(23)11-19-13-27(15-25(19)21)14-20-12-18-8-6-10-24(18)22(4-2)26(20)16-27/h11-12H,3-10,13-16H2,1-2H