Park Taiho, Zimmerman Steven C
Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
J Am Chem Soc. 2006 Nov 8;128(44):14236-7. doi: 10.1021/ja065469u.
In studies of a supramolecular network of polymers formed by self-association of UPy or UG recognition units displayed along a poly(butyl methacrylate) (PBMA) backbone, it was unexpectedly found that the more weakly dimerizing (Kdimer approximately 200 M-1) UG unit produced more assembly than did the very strongly dimerizing UPy unit (Kdimer = 2 x 107 M-1). Likewise, in examining supramolecular blends mediated by the heterocomplexation of DAN and UPy, which occurs upon the mixing of polystyrene containing the DAN unit (PS-DAN) and PBMA-UPy, increasing the mol % of UPy did not produce increased viscosity. 1H NMR showed that both observations can be explained by the intramolecular recognition of UPy. Structural studies show that the length of the chain linking the UPy unit to the backbone is critical, with longer linkers favoring intermolecular dimers. An interplay of linker chain length, polymer Mw, recognition unit mol %, and fidelity determines the extent of network growth.
在对由沿聚甲基丙烯酸丁酯（PBMA）主链展示的UPy或UG识别单元自缔合形成的聚合物超分子网络的研究中，意外地发现，二聚作用较弱（K二聚体约为200 M⁻¹）的UG单元比二聚作用非常强的UPy单元（K二聚体 = 2×10⁷ M⁻¹）产生更多的组装体。同样，在研究由DAN和UPy的异质络合介导的超分子共混物时，这种异质络合发生在含有DAN单元的聚苯乙烯（PS-DAN）和PBMA-UPy混合时，增加UPy的摩尔百分比并不会导致粘度增加。¹H NMR表明，这两种观察结果都可以通过UPy的分子内识别来解释。结构研究表明，将UPy单元连接到主链的链的长度至关重要，较长的连接基有利于分子间二聚体。连接基链长度、聚合物分子量、识别单元摩尔百分比和保真度之间的相互作用决定了网络生长的程度。
