State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter , Chinese Academy of Sciences , Fuzhou 350002 , PR China.
College of Chemistry , Liaoning University , Shenyang 110036 , PR China.
J Am Chem Soc. 2018 Apr 11;140(14):4869-4876. doi: 10.1021/jacs.8b00394. Epub 2018 Mar 28.
Transformations within container-molecules provide a good alternative between traditional homogeneous and heterogeneous catalysis, as the containers themselves can be regarded as single molecular nanomicelles. We report here the designed-synthesis of a water-soluble redox-active supramolecular PdL cage and its application in the encapsulation of aromatic molecules and polyoxometalates (POMs) catalysts. Compared to the previous known PdL cage, our results show that replacement of two cis-blocked palladium corners with p-xylene bridges through pyridinium bonds formation between the 2,4,6-tri-4-pyridyl-1,3,5-triazine (TPT) ligands not only provides reversible redox-activities for the new PdL cage, but also realizes the expansion and subdivision of its internal cavity. An increased number of guests, including polyaromatics and POMs, can be accommodated inside the PdL cage. Moreover, both conversion and product selectivity (sulfoxide over sulfone) have also been much enhanced in the desulfurization reactions catalyzed by the POMs@PdL host-guest complexes. We expect that further photochromic or photoredox functions are possible taking advantage of this new generation of organo-palladium cage.
在传统的均相和多相催化之间，容器分子内的转变提供了一种很好的替代方法，因为容器本身可以被视为单分子纳米胶束。我们在这里报告了一种水溶性氧化还原活性超分子 PdL 笼的设计合成及其在芳烃分子和多金属氧酸盐（POMs）催化剂的封装中的应用。与以前已知的 PdL 笼相比，我们的结果表明，用吡啶键将两个顺式封闭的钯角用对二甲苯桥取代，形成 2,4,6-三-4-吡啶基-1,3,5-三嗪（TPT）配体之间，不仅为新的 PdL 笼提供了可逆的氧化还原活性，而且实现了其内部腔的扩展和细分。更多的客体，包括多芳烃和 POMs，可以容纳在 PdL 笼内。此外，在由 POMs@PdL 主客体配合物催化的脱硫反应中，转化率和产物选择性（亚砜对砜）也得到了很大提高。我们期望利用这一代新的有机钯笼实现进一步的光致变色或光还原功能。
