Chemical Research in Chinese Universities ›› 2014, Vol. 30 ›› Issue (5): 715-719.doi: 10.1007/s40242-014-4065-3

Previous Articles     Next Articles

Third-order Optical Nonlinearities of a Series of Compounds Derived from a Keplerate Type Molybdenum-oxide-based Polyoxometalate

ZHOU Yunshan, QU Ningning, WANG Xuan, ZHANG Lijuan, SHI Zonghai, HASSAN ul Sadaf   

  1. State Key Laboratory of Chemical Resource Engineering, Institute of Science, Beijing University of Chemical Technology, Beijing 100029, P. R. China
  • Received:2014-03-03 Revised:2014-06-20 Online:2014-10-01 Published:2014-07-07
  • Contact: ZHOU Yunshan, ZHANG Lijuan E-mail:zhouys@mail.buct.edu.cn;ljzhang@mail.buct.edu.cn
  • Supported by:

    Supported by the National Natural Science Foundation of China(Nos.20541001, 20771012, 21371020) and the Program for Changjiang Scholars and Innovative Research Team in Universities of China(No.IRT1205).

Abstract:

By reacting the unique Keplerate type molybdenum-oxide based polyoxometalate (NH4)42·[Mo132O372·(CH3COO)30(H2O)72ca.300H2ca.10CH3COONH4(1) with tetramethylammonium bromide, a new derivative (NH4)26[TMA]16{Mo132O372(H2O)72(CH3COO)30ca.7NH4CH3COO·ca.189H2O(2, TMA=tetramethylammonium)was prepared. Compound 2 was characterized by Fourier transform infrared spectroscopy(FTIR), UV-Vis, elemental and thermogravimetric analyses. By the well-established Z-scan technique, investigations on the nonlinear optical(NLO) properties of the series of compounds derived from the Keplerate type molybdenum-oxide-based poly-oxometalate, namely, the newly prepared compound 2, the three previously reported compounds, included compound 1, (NH4)18(TBA)24{Mo132O372(H2O)72(CH3COO)30ca.7NH4CH3COO·ca.173H2O(3,TBA=tetrabutylammonium) and (DODA)40(NH4)2[(H2O)nMo132O372(CH3COO)30(H2O)72](4, DODA=dimethyldioctadecylammonium), reveal that the third-order nonlinearity[χ(3)] values of compounds 1, 2 and 3 in the DMF/H2O solution and compound 4 in chloroform are almost the same, which indicates that the counter cations with different length of alkyl chains show ignorable impacts on the NLO susceptibility. In other words, the remarkable third-order nonlinearities[χ(3)≈10-19 m2/V2] mainly come from the[Mo132O372(CH3COO)30(H2O)72]42- anions. This fact reveals that the applications of the NLO active polyoxometalates in various environments(such as hydrophilic, hydrophobic, polar, apolar, etc.) can be achieved by simply varying cations to meet the demands in the design of diverse devices.

Key words: Keplerate type polyoxometalate, Nonlinear optical property, Z-Scan technique, Self-defocusing, Reverse saturable absorption