Phase Transition from Photochemically Nonreactive Inclusion Complexes to Reactive Ones

2 Phase Transition from Optically Active Complexes to Rac-Ones in Crystals 

Since the two inner phenyl groups of 78 are overlapped, 78 becomes chiral in its crystals. Recrystallization of 78 from acetone yielded chiral crystals as orange hexagonal plates (A) and two types of rac-crystals as orange rectangular plates (B, mp 302 °C) and yellow rectangular plates (C, mp 297 °C) [42], X-ray crystal structures of A, B, and C have been analyzed [43], Crystal structures of B and C are completely different. When A was heated at 260 °C, it was converted to C [42], However, when A was put in contact with MeOH vapor, it was converted to B. 

3 Phase Transition from the Rac-lnclusion Complex to the Conglomerate One 

The rac-inclusion complex 79 consisting of 12 and Me4NCl 80 in a 1 1 ratio was easily converted into conglomerate complex 81 by heating or by contact with MeOH vapors in the solid state [42], Firstly, authentic samples of 79 and 81 were prepared by the following method. When 12 (1.43 g) and 80 (0.55 g) was recrystallized from 7 and 15 ml of MeOH, rac-79 and conglomerate 1 1 complex 81 were obtained, respectively. 

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