A second‐generationsupramoleculardendrimer has been prepared by orthogonal multiple hydrogen bonding. In the first (inner) recognition domain, the interaction of one bis‐isocyanuric acid (25) with two branching units (21) that carry complementary Hamilton receptors has been exploited. In the second (outer) generation, the two ADDA (A=hydrogen‐bond acceptor, D=donor) receptors of each branching unit
通过正交多重氢键制备了第二代超分子树状聚合物。在第一个(内部)识别域中,已利用了一个双异氰尿酸(25)与两个带有互补汉密尔顿受体的分支单元(21)的相互作用。在第二代(外部)中,每个分支单元(21个)的两个ADDA(A =氢键受体,D =供体)受体结合了互补的DAAD单元(4)。通过引入支链乙基己基残基和使用柔性亚烷基或低聚(乙二醇)连接链,已经克服了结构单元的溶解度有限的问题。通过化学诱导位移NMR滴定阐明了两个氢键对的正交结合,证明了这两个对具有汉密尔顿受体的异氰尿酸和具有DAAD的ADDA优先结合。通过扩散NMR光谱研究了分子量为5065 g mol -1的超分子自组装1:2:4树枝状大分子的形成。
Methylene chain ruler for evaluating the regioselectivity of a substrate-recognising oxidation catalyst
Regioselective C–H oxidation of aliphatic molecules with synthetic catalysts is challenging. We incorporated substrate-recognition sites into a ruthenium porphyrin–heteroaromatic N-oxide catalytic system in order to characterise its regioselectivity for the oxidation of alkanes. This substrate-recognition catalytic reaction exhibits high regioselectivity and high reaction efficiency.
amides. The association constants were determined by (1)H NMR titrations monitoring chemically induced shifts (CIS values), by (1)H NMRdiffusionexperiments, and by isothermal titration calorimetry (ITC), giving K(ass) values in chloroform at 298 K between 33 x 10(3) and 100 x 10(3) M(-1).
巴比妥和各种酰基氨基吡啶基间苯二甲酰胺(汉密尔顿受体)之间的主客体复合物形成已被定量确定。描述了九种间苯二甲酰胺的合成。它们的结构在中心间苯二甲酸单元上的取代模式和酰基残基的性质上有所不同。证明乙基己酰基衍生物比戊酰基酰胺更易溶解。缔合常数由 (1) H NMR 滴定监测化学诱导位移 (CIS 值)、(1) H NMR 扩散实验和等温滴定量热法 (ITC) 确定,在 298 K 的氯仿中给出 K(ass) 值介于 33 x 10(3) 和 100 x 10(3) M(-1) 之间。
作者:Adam Gooch、Natasha S. Murphy、Neil H. Thomson、Andrew J. Wilson
DOI:10.1021/ma402069b
日期:2013.12.23
Derivatives of thymine have been extensively used to promote supramolecular materials assembly. Such derivatives can be synthetically challenging to access and may be susceptible to degradation. The current article uses a conformer-independent acceptor-donor-acceptor array (ureidopyrimidine) which forms moderate affinity interactions with diamidopyridine derivatives to effect supramolecular blend formation between polystyrene and poly(methyl methacrylate) polymers obtained by RAFT which have been fimctionalized with the hydrogen bonding motifs.