摘要
We herein report the synthesis and metal-directed coordination self-assembly behaviors of three new macrocyc- lic azacalix[4]aromatics that comprise various numbers of pyridine and pyrazine rings bridged by N-CH3 groups. Structural characterization of 1--3 explored that their conformations are fluxional in solution and each adopts a 1,3-alternate configuration in crystalline solids. The macrocyclic skeletons in azacalixaromatic 1--3 afford a good platform to designedly arrange coordination sites in a unique way relative to conventional multidentate ligands. Solid-state structures of three coordination self-assembled silver complexes （13--15） of 1 --3 determined by X-ray crystallography suggest that the nitrogen atoms on procumbent aromatics have better coordination ability than those on perpendicular aromatics and dictate the whole coordination self-assemblies. Unique discrete and 1D chain-like structures were thus obtained. This system may afford a deeper insight into the coordination self-assembly studies of heteroatom-bridged calixaromatics, possibly extending potential application of this novel macrocyclic polyden- tate organic compounds in the synthesis of functional metal organic framework formation.
We herein report the synthesis and metal-directed coordination self-assembly behaviors of three new macrocyc- lic azacalix[4]aromatics that comprise various numbers of pyridine and pyrazine rings bridged by N-CH3 groups. Structural characterization of 1--3 explored that their conformations are fluxional in solution and each adopts a 1,3-alternate configuration in crystalline solids. The macrocyclic skeletons in azacalixaromatic 1--3 afford a good platform to designedly arrange coordination sites in a unique way relative to conventional multidentate ligands. Solid-state structures of three coordination self-assembled silver complexes （13--15） of 1 --3 determined by X-ray crystallography suggest that the nitrogen atoms on procumbent aromatics have better coordination ability than those on perpendicular aromatics and dictate the whole coordination self-assemblies. Unique discrete and 1D chain-like structures were thus obtained. This system may afford a deeper insight into the coordination self-assembly studies of heteroatom-bridged calixaromatics, possibly extending potential application of this novel macrocyclic polyden- tate organic compounds in the synthesis of functional metal organic framework formation.
基金
Financial support by the National Natural Science Foundation of China，the National Basic Research Program of China (973 program,2011CB932501 and 2013CB834501) is gratefully acknowledged.This work is also supported by Tsinghua University Initiative Scientific Research Program
