LiMoO 3(IO 3): A new molybdenyl iodate based on WO 3-type sheets with large SHG response

Abstract

A novel lithium molybdenyl iodate, LiMoO 3(IO 3), has been prepared by hydrothermal reactions at 170 °C. Its crystal structure has been determined from single-crystal X-ray data: space group P2 1, a = 5.4104(4) Å, b = 5.3158(3) Å, c = 9.0025(7) Å, β = 106.863(6)°, Z = 2. LiMoO 3(IO 3) is a new layered material containing [ Mo O 3 ( I O 3 ) ] 1 − anionic layers separated by Li + cations. The anionic layer has an unprecedented configuration consisting of WO 3-type sheets “capped” by IO 3 − groups. The iodate groups have their stereochemically active nonbonded electron pairs align along the b-axis, which creates the polarity in the structure. Second-harmonic-generation measurements on LiMoO 3(IO 3) display a response of about 4 × KH 2PO 4. DTA measurements demonstrate that LiMoO 3(IO 3) is stable up to at least 430 °C. UV–vis diffuse reflectance spectrum of this compound shows a high degree of transparency from 1.1 to 2.8 eV and a band gap of about 2.8 eV.