An Unprecedented Class of Benzoyldiazenido-Functionalized Polyoxometalates with Enhanced Antitumour Activities
Longsheng Wang,[a][‡] Panchao Yin,[a][‡] Jin Zhang,[a,b] Fengping Xiao,[a] Zhikun Fang,[c] Weiwei Fu,[d] Yongge Wei,*[a,b,c] Shijia Xue*[c]
[a] Department of Chemistry, Tsinghua University, Beijing 100084, P R China
[b] State Key Laboratory of Natural and Biomimetic Drugs, Peking University, Beijing 100191, P R China
[c] Department of Chemistry, Shanghai Normal University, Shanghai 200234, P R China
[d] School of Chemistry and Materials, Hengyang Normal University, Hunan 421000, China
[‡] Both authors contributed equally to this work
Eur. J. Inorg. Chem. 2017, 46, 5475-5484
DOI: 10.1002/ejic.201700990
Publication Date (Web): October 11, 2017
Copyright © The Royal Society of Chemistry 2018
*E-mail: yonggewei@tsinghua.edu.cn; sjxue@sohu.com;
An unprecedented class of benzoyldiazenido-functionalized polyoxometalates, [Bu4N]3[Mo6O18(=N=NCOAr)] (Ar=Ph, 1; Ph-o-Cl, 2; Ph-m-Cl, 3; Ph-p-Cl, 4; Ph-o,p-Cl2, 5; Ph-p-Br, 6; Ph-m-NO2, 7; Ph-p-NO2, 8; Ph-p-OMe, 9), are prepared through the reactions of α-octamolybdate and the corresponding hydrazides in dry acetonitrile under reflux with dicyclohexylcarbodiimide (DCC) as a dehydrating agent. Single-crystal X-ray diffraction structural analysis reveals that their anions demonstrate the typical structural features of monofunctionalized hexamolybdates with different organic substituents. 1H NMR spectroscopy indicates that the [Mo6O18(NN)] fragments in these compounds are electron-donating groups rather than electron-withdrawing groups, and this behaviour was further validated by the calculation of the atomic-charge distributions [natural bond orbital (NBO) and Mülliken]. Cyclic voltammetry (CV) indicates that they are more difficult to reduce than hexamolybdate and its organoimido derivatives. Antitumour activity tests against K562 show that most of the hybrid compounds have enhanced inhibitory activities compared with those of hexamolybdate and the corresponding hydrazide ligands.