HEXASULFONATED CALIX[6]ARENE DERIVATIVES - A NEW CLASS OF CATALYSTS, SURFACTANTS, AND HOST MOLECULES
HEXASULFONATED CALIX[6]ARENE DERIVATIVES - A NEW CLASS OF CATALYSTS, SURFACTANTS, AND HOST MOLECULES
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DOI：
10.1021/ja00269a045
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发表时间：
1986-04-30
影响因子：
15
通讯作者：
MANABE, O
中科院分区：
文献类型：
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作者：
SHINKAI, S;MORI, S;MANABE, O
首次合成了水溶性的六磺化杯[6]芳烃，并将其作为主体分子应用于水体系中。动态1H NMR研究表明，杯[6]芳烃-对-己磺酸酯（1-H）在D2O-Me2SO-d6（2：1 v/v）体系中由于OH基团间的氢键作用而呈现"翅式"或"铰链式"构象，而5，11，17，23，29，35-己磺酸基-37，38，39，40，41，42-六（己氧基）杯[6]芳烃（1-C6）在D2O体系中由于己基基团间的疏水键作用而呈现类似构象.考察了1-C6和1-C12在水中的聚集行为。物理（光散射、表面张力和电导）和光谱（荧光和吸收光谱）研究确定1-C6的cmc约为1.5。6倍。10-4 M，十二烷基硫酸钠（SDS）也是如此，而1-C12没有可检测到的cmc，而是作为"单分子"胶束。事实上，1-C6与小分子（芘，2-苯胺基萘，和橙子OT）根据胶束样的双相浓度依赖性，而1-C12与这些分子形成主客体类型的1：1复合物。结果表明，这些杯[6]芳烃衍生物能有效地促进1-苄基-1，4-二氢烟酰胺的酸催化水合反应，反应符合Michaelis-Menten动力学。特别是，1-H和1-CH 2COOCH，这两者都有酸性质子催化反应和阴离子磺酸盐，以稳定阳离子中间体在两个边缘的空腔的速率常数，是由426 - 1220倍，比那些非环状类似物。这些发现表明六磺化杯[6]芳烃作为一类新的催化剂，表面活性剂和主体分子。这是杯芳烃在水溶液体系中观察到的主客体型行为的第一个例子。
Water-soluble hexasulfonated calix[6]arenes with various substituents (1-R) have been synthesized for the first time and applied as host molecules in an aqueous system. Dynamic 1H NMR studies established that calix[6]arene-p-hexasulfonate (1-H) adopts a "winged" or "hinged" conformation in D2O-Me2SO-d6 (2:1 v/v) owing to hydrogen bonding among the OH groups, while 5,11,17,23,29,35-hexasulfonato-37,38,39,40,41,42-hexakis(hexyloxy)calix[6]arene (1-C6) adopts a similar conformation in D2O owing to hydrophobic bonding among the hexyl groups. The aggregation behavior in water was examimed about 1-C6 and 1-C12. Physical (light-scattering, surface tension, and conductance) and spectral (fluorescence and absorption spectroscopies) studies established that 1-C6 has a cmc at ca. 6 .times. 10-4 M, as does sodium dodecyl sulfate (SDS), while 1-C12 has no detectable cmc and rather acts as a "unimolecular" micelle. In fact, 1-C6 associated with small molecules (pyrene, 2-anilinonaphthalene, and Orange OT) according to the micelle-like biphasic concentration dependence, while 1-C12 formed host-guest-type 1:1 complexes with these molecules. It was found that these calix[6]arene derivatives efficiently accelerate acid-catalyzed hydration of 1-benzyl-1,4-dihydronicotinamide and the reaction proceeds according to the Michaelis-Menten kinetics. In particular, the rate constants for 1-H and 1-CH2COOCH, which both have acidic protons to catalyze the reaction and anionic sulfonates to stabilize the cationic intermediate at the two edges of the cavity, were greater by 426-1220-fold than those for noncyclic analogues. These findings indicate that hexasulfonated calix[6]arenes serve as a new class of catalysts, surfactants, and host molecules. This is the first example for the host-guest-type behavior of calixarenes observed in an aqueous system.