A Cu(II) metallocycle for the reversible self-assembly of coordination-driven polyrotaxane-like architectures

摘要

We report the design and synthesis of a Cu(II) metallocycle (1) and use the possibility to expand the Cu(II) coordination sphere to self-assemble mechanically interlocked species via interpenetration. Metallocycle 1 can be used as a platform to reversibly assemble a 1D + 1D. 1D coordination-driven polyrotaxane (3), where 1 acts as the hosting ring as well as the stopper, and 4,4'-bipyridine is the guest-axle. A coordinating solvent can substitute the 4,4'-bipyridine axle to disassemble the polyrotaxane (3. 2) that is easily restored by further adding 4,4'-bipyridine (2 - 3). Other polyrotaxanes can be isolated by reacting 1 with pyridine (4) and phenylpyridine (5). Interconversion among the presented species is demonstrated and ensured by the open position of each copper center in platform 1.