Synthesis And Characterization Of Mono-and Di-ethynyl Pyridine And Their Au(I) Complexes

Recently growing interest in the study of metal ethynide complexes stems from their structural diversity and technological application as precursors of nonlinear optical materials, luminescent materials, and rigid-rod molecular wires.Mono- or di- ethynyl pyridine can not only use the ethynyl to coordinate with the low-valent transion metals, but also afford a free N atom, which could participate in self-assembly reactions. Through the incovalent incorporation of functional groups, their structures can be manipulated to provide desirable physical properties tailored for specific applications.In this work, we have syntheized and fully characterized a series of pyridylacetylenes: 2,6-diethynylpyridine, 3,5-diethynylpyridine and 4-ethynylpyridine. And a direct reaction of AuPPh₃Cl with ethynyl pyridine leads to two dinuclear Gold(I) complexes [(AuPPh₃)₂{μ-(C≡C)₂Py}] (Py=2,6-diyl) and [(AuPPh₃)₂{μ-(C≡C)₂Py}] (Py=3,5-diyl) whih rigid structures. X-ray crystallographic study of [(AuPPh₃)₂{μ-(C≡C)₂Py}](Py=2,6-diyl) reveals that the N of pyridine is not coordinate with other atoms, and two AuPPh₃ units are coordinated to the ethynyl fragments of the 2,6-pyridinediethyndiyl ligand, both gold atoms being in almost linear environments (C-Au(I)-P=167(3)°), the distance between the two gold is so long that there is no interaction between them. Aditionally, the molecules of [(AuPPh₃)₂{μ-(C≡C)₂Py}](Py=2,6-diyl) are packed throughÏ€-Ï€interaction to give a infinite network.The obtained results indicate that these complexes can be used as a model for the study of the relations between luminescence property and the structure, and also novel building blocks to assemble supramolecules.