aDepartment of Materials Technology, Faculty of Engineering, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522, Japan
bGraduate School of Science and Technology, Chiba University, 1-33 Yayoicho, Inageku, Chiba 263-8522, Japan
Abstract:
A crystalline dipeptide, (R)-phenylglycyl-(R)-phenylglycine (RR-1), recognized p-halobenzyl methyl sulfoxides with high R-enantioselectivity (86–99% ee) to form inclusion compounds. The single-crystal X-ray analyses showed that RR-1 molecules are arranged in parallel and zigzags via hydrogen bonding to construct a pleated sheet. The guest molecules that form hydrogen bond with +NH3 of RR-1 are accommodated in the channel cavity between the layers. In contrast to the inclusion crystals of parent benzyl methyl sulfoxide, in which a rectangular cavity is formed, the cavity including p-halobenzyl methyl sulfoxides becomes rhomboidal. We also examine the guest exchange in these inclusion compounds and it was found that the guest exchanges occur when the host structure changes.