Interaction of dihydroxy host systems with glycols. A comparative study of the crystal structures of 1:1 molecular complexes of 1,4-butanediol with 2,5-bis(4-chlorophenyl)hydroquinone andtrans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene

The title compounds crystallize in space groupC2/c withZ=4; C₁₈H₁₂O₂Cl₂·HO(CH₂)₄OH,a=16.186(3),b=7.626(1),c=16.939(3) Å, =91.32(2)°,R_F=0.048 for 1743 observed MoK reflections; C₂₆H₂₀O₂·HO(CH₂)₄OH,a=11.881(3),b=13.009(4),c=16.689(4) Å, =110.67(2)°,R_F=0.066 for 1783 data points. Both structures feature centrosymmetric hydrogen-bonded (OH)₄ rings formed by molecular components located in special positions. Different packing modes account for the observed conformations (g⁺ag^– andaaa, respectively) of 1,4-butanediol and its possible replacement by 1,2-ethanediol as a guest in the former crystal structure.Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82009 (25 pages).Dedicated to Professor H. M. Powell.