Crown bowl: metallocyclophane by self-assembly of 4'-pyridylmethyl-armed 12-crown-4 ethers with Ag+ ions.
New 3'-pyridylmethyl- and 4'-pyridylmethyl-armed monoaza-12-crown-4 ethers were prepared by the reductive amination of monoaza-12-crown-4 with the appropriate pyridinecarbaldehyde in the presence of NaBH(OAc)3. X-ray crystallography, cold electrospray ionization mass spectrometry, and 1H NMR titration experiments show that Ag+ complexes with 3'-pyridylmethyl- and 4'-pyridylmethyl-armed monoaza-12-crown-4 ethers are dimetallo[3.3]metacyclophane and trimetallo[3.3.3]paracyclophane, respectively (crown bowl). The structure of the metallocyclophanes can be controlled by the positions of the N atoms in the pyridine side arms and the ring size of the crown moiety.
Habata
Yoichi
Y
Department of Chemistry, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan. habata@chem.sci.toho-u.ac.jp
Yamada
Sachiko
S
Osaka
Futoshi
F