TRIOL CRYSTALLINE HOSTS DERIVED FROM MALIC-ACID - SYNTHESIS, INCLUSION FORMATION AND X-RAY CRYSTAL-STRUCTURES OF A FREE HOST AND ITS INCLUSION COMPOUND WITH ETHANOL (1 1)/

Four new host compounds 1-3 (a, b) derived from malic acid as differen t optical species and having particular lateral substituents were synt hesized. Their properties in crystalline inclusion formation were stud ied and discussed. Crystal structures of a free host compound 1 and it s ethanol inclusion complex [1 . EtOH (1:1)] been determined by X-ray analysis [1:orthorhombic, P2(1)2(1)2(1), a = 9.304(3), b = 14.950(3), c = 15.712(3) Angstrom, Dc = 1.248 Mg . m(3), Z = 4, R = 0.039 for 247 4 reflexions; 1 . EtOH (1:1): triclinic, <P(1)over bar>; a = 11.945(3) , b = 14.080(3), c = 16.029(4) Angstrom = 106.82(2), beta = 97.74(2), gamma = 89.93(2)degrees, D-c = 1.187 Mg . m(3), Z = 4, R = 0.096 for 1 0404 data]. Spontaneous resolution occurs during crystallization in cr ystals of 1. An interesting H-bonding pattern develops that probably i s responsible for the inclusion formation with ethanol in the associat e crystal.