Toward the Self-Assembly of Metal−Organic Nanotubes Using Metal−Metal and π-Stacking Interactions: Bis(pyridylethynyl) Silver(I) Metallo-macrocycles and Coordination Polymers

Shape-persistent macrocycles and planar organometallic complexes are beginning to show considerable promise as building blocks for the self-assembly of a variety of supramolecular materials including nanofibers, nanowires, and liquid crystals. Here we report the synthesis and characterization of a family of planar di- and tri-silver(I) containing metallo-macrocycles designed to self-assemble into novel metal−organic nanotubes through a combination of π-stacking and metal−metal interactions. The silver(I) complexes have been fully characterized by elemental analysis, high resolution electrospray ionization mass spectrometry (HR-ESI-MS), IR, 1H and 13C NMR spectroscopy, and the solution data are consistent with the formation of the metallo-macrocycles. Four of the complexes have been structurally characterized using X-ray crystallography. However, only the di-silver(I) complex formed with 1,3-bis(pyridin-3-ylethynyl)benzene is found to maintain its macrocyclic structure in the solid state. The di-silver(I) shape-persistent macrocycle assembles into a nanoporous chicken-wire like structure, and ClO4− anions and disordered H2O molecules fill the pores. The silver(I) complexes of 2,6-bis(pyridin-3-ylethynyl)pyridine and 1,4-di(3-pyridyl)buta-1,3-diyne ring-open and crystallize as non-porous coordination polymers.

形状恒定的宏环和平面有机金属配合物作为多种超分子材料（包括纳米纤维、纳米线和液晶）自组装的构建模块，正逐渐展现出巨大的潜力。在本研究中，我们报道了一系列平面二银(I)和三银(I)金属宏环的合成与表征，这些金属宏环旨在通过π-堆积和金属-金属相互作用自组装成新型金属-有机纳米管。银(I)配合物已通过元素分析、高分辨率电喷雾电离质谱法（HR-ESI-MS）、红外光谱、1H和13C核磁共振光谱进行了全面表征，且溶液数据与金属宏环的形成一致。其中四种配合物通过X射线晶体学进行了结构表征。然而，只有与1,3-双(吡啶-3-基乙炔基)苯形成的二银(I)配合物在固态下保持了其宏环结构。该二银(I)形状恒定的宏环组装成类似纳米多孔铁丝网的结构，ClO4−阴离子和无序的H2O分子填充了孔隙。2,6-双(吡啶-3-基乙炔基)吡啶和1,4-二(3-吡啶基)丁二炔环的银(I)配合物发生开环并作为非多孔配位聚合物结晶。