3,3,6,6-Tetramethyl-9-[6-(3,3,6,6-tetramethyl-1,8-dioxo-2,3,4,5,6,7,8,9-octahydro-1<i>H</i>-xanthen-9-yl)pyridin-2-yl]-2,3,4,5,6,7,8,9-octahydro-1<i>H</i>-xanthene-1,8-dione
Acta crystallographica. Section E