Three novel polyoxoanion-supported compounds: confinement of polyoxoanions in Ni-containing rigid concave surfaces with enhanced NLO properties

摘要

Three novel polyoxoanion-supported compounds modified by conjugated organic ligand tris(2-benzimidazylmethyl) amine (NTB) and nickel ions, [Ni(NTB)(H2O)](2)(H2P2Mo5O23)center dot 9.25H(2)O (1), [Ni(H2O)-( NTB)](2)((PMo11MoO40)-Mo-VI-O-V)center dot 4.5H(2)O (2) and [Ni(NTB)](2)(Mo8O26)center dot 9H(2)O (3), have been successfully synthesized under hydrothermal conditions at different pH values. The compounds 1-3 contain similar rigid concave surfaces composed of [Ni(NTB)](2+) cations, which connect with different clusters to form the first examples of metal-NTB-modified polyoxoanion-supported compounds. Transition metal-containing rigid concave surfaces successfully confine polyoxoanions in compounds 1-3. In the synthesis of the three compounds, the pH values play an important role in the formation of polyoxoanions and the stability of the compounds. Additionally, the third-order nonlinear optical properties (NLO) and electrochemical behaviors were also investigated.