title: Cs(TaO2)3(SeO3)2 and Cs(TiOF)3(SeO3)2: structural and second harmonic generation changes induced by the different d(0)-TM coordination octahedra.
abstract: Two new cesium selenites containing TaO6 or TiO4F2 octahedra, namely, Cs(TaO2)3(SeO3)2 (1) and Cs(TiOF)3(SeO3)2 (2), have been prepared using standard high temperature solid-state method and hydrothermal reaction, respectively. Compound 1 crystallizes in P3̅m1 and features an unusual [(TaO2)3(SeO3)2](-) sandwich-like double layer in which two [Ta(1)O3(SeO3)](3-) layers are bridged by central Ta(2)O6 octahedra via corner-sharing, whereas Cs(TiOF)3(SeO3)2 with a polar space group P63mc features an interesting hexagonal tungsten oxide (HTO) layered topology and presents a strong second harmonic generation (SHG) of about 5 × KDP (KH2PO4), which is much larger than those of A(VO2)3(QO3)2 (A = K, Tl, Rb, Cs, or NH4; Q = Se, Te) with a similar HTO layered structure. Cs(TiOF)3(SeO3)2 is also type-I phase matching. The SHG of above-mentioned HTO materials can be enhanced greatly with the replacement of VO6 octahedra by TiO4F2 octahedra. Furthermore, thermal stabilities, UV-vis diffuse reflectance spectra, infrared spectra, relationship between crystal structure and SHG, and theoretical calculations were also reported.
authors.affiliation: †State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.|‡University of the Chinese Academy of Sciences, Beijing 100039, P. R. China.
authors.forename: Xue-Li
authors.initials: XL
authors.lastname: Cao
authors.affiliation: †State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
authors.forename: Chun-Li
authors.initials: CL
authors.lastname: Hu
authors.affiliation: †State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
authors.forename: Fang
authors.initials: F
authors.lastname: Kong
authors.affiliation: †State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China.
authors.forename: Jiang-Gao
authors.initials: JG
authors.lastname: Mao