Polymorphism of inclusion complexes and unsolvated hosts .2. Structure of the beta-dimorph of the host-guest complex of dianilinegossypol with ethylacetate

Depending on crystallization conditions, dianilinegossypol and ethylacetate form low (ambient temperature, alpha-phase) and high temperature (t = 35 degrees C, beta-phase) clathrate modifications. The structure of the alpha-phase has been discussed earlier [1]. Crystals of the 1:1 beta-phase complex, C42H40O6N2 . C4O2H8, are monoclinic, space group P2(1)/c, a = 11.362(6), b = 19.479(9), c = 19.085(9) Angstrom, beta = 103.21(4)degrees, V = 4112(3) Angstrom(3), Z = 4, R = 0.084 for 3210 observed reflections. In these complexes centrosymmetric dimers of dianilinegossypol molecules formed via O(5)-H ... O(3) hydrogen bonds are associated into columns by a weak O(8)-H ... O(7) H-bond. A difference in the structure of these two phases is in the packing mode of the columns. The angle formed by intersecting host columns is about 126 degrees for the alpha-phase and 104 degrees for the beta-modification. Guest molecules are hydrogen bonded to the host molecules via an O(1)-H ... O(10) bond and are accommodated in channels in alpha-phase complex and in cavities in beta-phase complex.