摘要:
A giant, 100-membered metallocycle 3 was prepared via coordination bond-based self-assembly from W-shaped ligand 9 and a palladium complex. Metallocycle 3 may create three topologically discrete subcavities, thus capable of binding up to three molecules of a diamide guest by hydrogen-bonding interactions. Elemental analysis, H-1 NMR, and the ESI-mass spectra, and vapor pressure osmometry (VPO) data were all consistent with the structure of 3. N,N,N',N'-tetramethylterephthalamide G was used as a guest for the binding study, and ESI-mass spectrum clearly displayed a characteristic, intense peak at m/z 1542 (41%), attributed to the fragment [3-G(3)-3CF(3)SO(3)](3+) of 1:3 (host/guest) complex. The 1H NMR titration experiments gave association constants of 2300 +/- 300 and 1200 +/- 200 M-1 in CDCl3 at 25 degrees C for two identical outer cavities, with weak positive cooperativity (Hill coefficient h = 1.3). (c) 2005 Elsevier Ltd. All rights reserved.