Zeng Mengyan, Chen Kun, Tan Junyan, Zhang Jie, Wei Yongge
Key Lab of Organic Optoelectronics & Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China.
Beijing National Lab for Molecular Sciences, Key Lab of Polymer Chemistry and Physics of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing, China.
Front Chem. 2018 Oct 16;6:457. doi: 10.3389/fchem.2018.00457. eCollection 2018.
Oxidizing aldehydes to generate carboxylic acids is a crucial reaction in nature and in chemical industry. The aldehyde oxidation, an easily achieved process in liver cells, is inert toward autoxidation in industrial production and difficultly achieved under enzymatic condition (in water, at pH 7, at room temperature). Herein, we prepared a supramolecular catalyst which are nanospheres assembled in aqueous media by chromium centered Anderson polyoxometalates Na[CrMoO(OH)] (namely, CrMo) and cationic pillar[5]arenes (namely, P5A) with 10 positive charges which can be used as the phase transfer catalysts (PTCs). This supramolecular catalyst was exploited on aldehydes oxidation under enzymatic condition with relatively good conversion. Through DLS monitoring, the diameters of nanospheres were variable while changing the charge ratios of the ionic complexes (P5A-CrMo), and it is probably because of the closer charge ratios causing the more compact assemblies. Also, the nano-morphologies were monitored by TEM and SEM, and the nanostructures were characterized by zeta potential, the X-ray energy-dispersive spectroscopy (EDS), elemental analysis.
将醛氧化生成羧酸是自然界和化学工业中的关键反应。醛的氧化在肝细胞中是一个容易实现的过程，但在工业生产中对自氧化呈惰性，并且在酶促条件下（在水中，pH 7，室温）很难实现。在此，我们制备了一种超分子催化剂，它是由以铬为中心的安德森多金属氧酸盐Na[CrMoO(OH)]（即CrMo）和带有10个正电荷的阳离子柱[5]芳烃（即P5A）在水介质中组装而成的纳米球，可作为相转移催化剂（PTCs）。这种超分子催化剂用于酶促条件下的醛氧化反应，具有相对较好的转化率。通过动态光散射监测，在改变离子络合物（P5A-CrMo）的电荷比时，纳米球的直径是可变的，这可能是因为电荷比越接近，组装体越紧密。此外，通过透射电子显微镜和扫描电子显微镜监测纳米形态，并用zeta电位、X射线能量色散光谱（EDS）、元素分析对纳米结构进行表征。
