1,1',2,2'-tetrahydro-3H,3'H-1,1'-biindene-3,3'-dione InChI=1/C18H14O2/c19-17-9-15(11-5-1-3-7-13(11)17)16-10-18(20)14-8-4-2-6-12(14)16/h1-8,15-16H,9-10H [1,1'-bi-1H-indene]-3,3'(2H,2'H)-dione