organic compounds
1,5-Bis(4-chlorophenyl)-3-(2-oxo-1,2-dihydroquinolin-3-yl)pentane-1,5-dione, (Ia), and 1,5-bis(2-chlorophenyl)-3-(2-oxo-1,2-dihydroquinolin-3-yl)pentane-1,5-dione, (Ib), crystallize as an 84:16 mixture, 0.84C26H19Cl2NO3·0.16C26H19Cl2NO3, in the space group I41/a, where the molecules of the two isomers occupy very similar sites in the unit cell. A combination of one N—HO hydrogen bond and one C—HO hydrogen bond links the molecules, regardless of isomeric form, into a single three-dimensional framework structure. The molecules of (9RS,10RS)-8,9-bis(4-chlorobenzyl)-10-(2-oxo-1,2-dihydroquinolin-3-yl)-5,6,9,10-tetrahydrophenanthridine, C36H22Cl2N2O4, (II), are linked by two hydrogen bonds, one each of the N—HO and C—HO types, into a molecular ribbon in which centrosymmetric rings of R22(18) and R44(24) types alternate. The hydrogen-bonded ribbons enclose channels, which contain highly disordered solvent molecules.