Guest induced head-to-tail columnar assembly of 5,17-difunctionalized calix[4] arene

摘要

Calix[4] arene possessing two catechol side arms 1 and organic molecules (nPrOH, AcOH, AcOEt, and CH3CN) crystallized to afford cocrystals: 1 center dot(nPrOH)(4), 1 center dot(AcOH)(4), 1 center dot(AcOEt), and 1 center dot(CH3CN)(2). In these cocrystals, calix[4] arene 1 is arranged one-dimensionally, forming head-to-tail columnar structures. The organic guests settle in the residual space between the columnar structures; they are captured by the catechol side arms through hydrogen bonding. In the cocrystal 1 center dot(H2O)(2), a continuous zigzag array of 1 is formed instead of the columnar assembly, demonstrating that the organic guests induced the formation of the head-to-tail columnar structures in the crystal packing. The crystalline apohost 1(apo) was prepared by the desorption of the MeOH guests from the cocrystal 1 center dot(MeOH)(4); this compound adsorbed the MeOH vapour, reconstructing the original crystal packing. When 1(apo) adsorbed the iPrOH vapour, a cocrystal with a crystal structure similar to that of 1 center dot(MeOH)(4) was formed, suggesting that 1(apo) has a crystal structure similar to that of 1 center dot(MeOH)(4).