| Summary: | 博士 === 淡江大學 === 化學學系 === 88 === The self-organization of small molecules into helical structures could be found easily in living system. There are several sophisticated inorganic helicates have been developed. We aimed to introduce the hydrazone group to link polypyridyl binding domain, it plays two roles; both binding, and bridging unit, it also could be deprotonated to modulate the electronic coupling in multinuclear system.
A family of novel polypyridyl type multi-binding domains ligands containing hydrazone linker were synthesized successfully, after complexed with Ag(l) or Cu(I) respectly, gives double helicates only, including dinuclear helicates, [Ag2(m-Ph-M-(Bpy)2)2](X)2, [Ag2(Bpy-(M-Pz)2)2](Z)2, [Ag2(Bpy-(M-Thio)2)2](Z)2, [Ag2(Bpy-(H-MThio)2)2](Z)2, trinuclear helicates, [Ag3(Py-M-(Bpy)2)2](X)3, [Ag3(Py-M-(Bpy)2)2](Y)3 [Ag3(C2-M-(Bpy)2)2](Z)3, [Ag3(C2-Ph-(Bpy)2)2](Z)3, [Ag3(Bpy-(H-M2Py)2)2](Z)3, [Cu3(Bpy-(H-M2Py)2)2](Z)3, [Ag3(Bpy-(M-Pz)2)2](Z)3, and finally a unique petanuclear helicate [Ag5(Bpy-(HC2H-Bpy)2)2](Z)5, (X=ClO4, Y=PF6, Z= CF3SO3). Solid state structures of complexes list above were confirmed by Xray diffractometry.The composition and Solution structures were also examined by FAB, ESI Mass and NMR method (COSY,NOESY), the results confirmed the double helix structure is maintained in the solution state.
The self-recognition process and cooperative phenomena were studied by NMR and spectrophotometric experiments including UV-Vis,NMRand ESI titration, for helicates [Ag2(m-Ph-M-(Bpy)2)2]2+, [Ag3(Py-M-(Bpy)2)2]3+ , they express highly positive cooperation in individual ligand and self-recognition between ligands. The self-assembling process and reaction mechanism were investigated by means of sytematic measurement of step-wise and overall stability constant
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