Molecular recognition of polymethoxybenzenes by host molecule comprised of two pyromellitic diimides and two dialkoxynaphthalenes

作者：Nakagaki Takeshi; Shin ichiro Kato; Harano Aya; Shinmyozu Teruo^*

来源：Tetrahedron, 2010, 66(4): 976-985.

DOI：10.1016/j.tet.2009.11.087

• Pyromellitic diimide
• Macrocycle
• Molecular recognition
• Charge transfer interaction

For the continuing study of the molecular recognition of the pi-electron-poor host comprised of two pyromellitic diimides and two dialkoxynaphthalenes, its inclusion with pi-electron-rich polymethoxybenzenes has been examined. The UV-vis titration studies indicated following order of the association constants (K(a)'s) as 1:1 complexes in CHCl(3): 1,3,5-trimethoxybenzene (31.3 M(-1))>1,3-dimethoxybenzene (9.2 M(-1))>1,2-dimethoxybenzene (6.5 M(-1))>1,4-dimethoxybenzenes (2.8 M(-1)). The X-ray structural analysis of the complexes between the host and dimethoxybenzenes proved the intracavity 1:1 complexes and provided useful information on the structures of the complexes. Not only charge transfer interactions but also other weak interactions such as electrostatic, van der Waals, and the unique hydrogen bonds between the a-hydrogen atoms of the naphthalene and the methoxy oxygen atoms were considered to be responsible for the magnitude of the Ka's. Thus molecular recognition of polymethoxybenzenes has been accomplished by the neutral host using multipoint weak interactions in an organic solvent.

• 出版日期2010-1-23