Gravar-mail: Crystal structure of 1,1′-{(1E,1′E)-[4,4′-(9H-fluorene-9,9-di­yl)bis­(4,1-phenyl­ene)]bis­(aza­nylyl­idene)bis(methanylyl­idene)}bis­(naphthalen-2-ol) di­chloro­benzene monosolvate