Anion-responsive covalently linked and metal-bridged oligomersf

摘要

Ethynyl-substituted acyclic anion receptors were synthesized for discrete covalently linked and metal-bridged dimers, which form various anionic complexes including double helical structures as the first examples of Cl~-bridged [2 + 2]-type complexes that are stable in the solution state. The appropriate arrangement of multiple receptor units is an essential fabrication strategy of functional assembled architectures such as helicates and grid-like structures comprising multiple building components. Ion binding is an effective protocol to tightly connect multiple building units using a small number of noncovalent bonds. In sharp contrast to the numerous reports on metal cations as the glue connecting π-conjugated species, there have only been a few reports on halide anions that construct [n + n]-type discrete assemblies in the solution state.