Department of Chemistry and Pharmacy and Interdisciplinary Center of Molecular Materials, Friedrich-Alexander-Universität, Erlangen-Nürnberg, Henkestrasse 42, 91054-Erlangen, Germany.
Chemistry. 2013 Feb 18;19(8):2814-25. doi: 10.1002/chem.201203863. Epub 2013 Jan 10.
We report on the very facile access of a new family of amphiphilic and bola-amphiphilic fullerene [5:1]hexakisadducts 9a-f and 11a-e. The key point for this successful approach is the use of C(2v)-symmetrical fullerene pentakisadduct precursors 2b-f allowing for the completely regioselective addition of a sixth malonate addend to complete the octahedral [5:1] addition pattern. For the synthesis of the new amphiphiles we first developed a new second-generation dendrimer containing 9 tert-butoxycarbonyl (Boc)-protected amino functions at the periphery and two new malonates containing 6 or 18 Boc-protected amino termini, respectively. The hexakisadducts contain up to 18 positive or negative charges at the dendritic moiety and either no or ten positive or negative charges at the unbranched malonate positions after deprotection with trifluoroacetic acid (TFA). The charge state at the termini is pH-dependent. Complete structural characterization of the new compounds was carried out by ESI mass spectrometry and by UV/Vis, FTIR, (1)H NMR and (13)C NMR spectroscopy. We were also able to obtain the first X-ray crystal structure of pentakisadduct (2a) with a C(2v)-symmetrical addition pattern. The new amphiphilic hexakisadducts show interesting solubility properties in water. Initial investigations on the aggregation properties of the amphiphilic hexakisadduct 12c by using dynamic light scattering (DLS) and conductivity measurements, show aggregates with a radius up to 200 nm and a critical micelle concentration (CMC) of approximately 8 mg L(-1).
我们报告了一种新的双亲性和双锥型富勒烯[5:1]六加成物 9a-f 和 11a-e 的简便制备方法。这种成功方法的关键是使用 C(2v)-对称的富勒烯五加成物前体 2b-f，允许第六个丙二酸加成物完全区域选择性地加成，以完成八面体[5:1]加成模式。为了合成新的两亲物，我们首先开发了一种第二代树状大分子，其外围含有 9 个叔丁氧羰基（Boc）保护的氨基，以及两个分别含有 6 个或 18 个 Boc 保护的氨基末端的新丙二酸。六加成物在树枝状部分含有多达 18 个正电荷或负电荷，并且在用三氟乙酸（TFA）脱保护后，在无支链的丙二酸位置上含有 0 个、10 个正电荷或负电荷。末端的电荷状态取决于 pH 值。通过电喷雾质谱（ESI-MS）和紫外可见光谱、傅里叶变换红外光谱（FTIR）、（1）H NMR 和（13）C NMR 光谱对新化合物进行了完整的结构表征。我们还获得了具有 C(2v)-对称加成模式的五加成物（2a）的第一个 X 射线晶体结构。新的两亲性六加成物在水中具有有趣的溶解性能。通过动态光散射（DLS）和电导率测量，对两亲性六加成物 12c 的聚集性质进行了初步研究，结果表明其聚集物的半径可达 200nm，临界胶束浓度（CMC）约为 8mgL(-1)。
