ten Cate Mattijs G J, Huskens Jurriaan, Crego-Calama Mercedes, Reinhoudt David N
Laboratory of Supramolecular Chemistry and Technology, MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
Chemistry. 2004 Aug 6;10(15):3632-9. doi: 10.1002/chem.200400085.
The self-assembly of hydrogen-bonded aggregates (rosettes) in solvent mixtures of different polarity has been studied by calorimetry. The C(50) parameter, the concentration when 50 % of the components are incorporated in the assembly, is used to compare assemblies with different stoichiometry. C(50) for the single rosette 1(3).(BuCYA)(3) (1=N,N-di(4-tert-butylphenyl)melamine; BuCYA=n-butylcyanuric acid) in 1,2-dichloroethane is 25 microM, whereas for double rosettes 2 a(3).(BuCYA)(6) and 2 b(3).(BuCYA) (2=calix[4]arene-dimelamine) it is 0.7 and 7.1 microM, respectively. DeltaG degrees, DeltaH degrees, and TDeltaS degrees values indicate that the thermodynamics of double rosettes reflect the independent assembly of two individual single rosette structures or two rosettes reinforced by additional stabilizing interactions. In more polar solvents the stability of double rosettes decreases. From the correlation of DeltaG degrees with solvent polarity it is predicted that it should be possible to assemble double rosettes in methanol or water. The assembly of 2 b(3).(BuCYA)(6) in 100 % MeOH was proven by (1)H NMR and CD spectroscopy.
通过量热法研究了不同极性溶剂混合物中氢键聚集体（玫瑰花结）的自组装。C(50)参数，即50%的组分并入组装体时的浓度，用于比较不同化学计量比的组装体。单玫瑰花结1(3)·(BuCYA)(3)（1=N,N-二(4-叔丁基苯基)三聚氰胺；BuCYA=正丁基氰尿酸）在1,2-二氯乙烷中的C(50)为25 μM，而双玫瑰花结2 a(3)·(BuCYA)(6)和2 b(3)·(BuCYA)（2=杯[4]芳烃-二三聚氰胺）的C(50)分别为0.7 μM和7.1 μM。ΔG°、ΔH°和TΔS°值表明，双玫瑰花结的热力学反映了两个单独的单玫瑰花结结构或通过额外稳定相互作用增强的两个玫瑰花结的独立组装。在极性更强的溶剂中，双玫瑰花结的稳定性降低。根据ΔG°与溶剂极性的相关性预测，应该有可能在甲醇或水中组装双玫瑰花结。通过1H NMR和CD光谱证明了2 b(3)·(BuCYA)(6)在100%甲醇中的组装。
