【文章名】Functionalization of Borate Networks by the Incorporation of Fluoride: Syntheses, Crystal Structures, and Nonlinear Optical Properties of Novel Actinide Fluoroborates
Functionalization of Borate Networks by the Incorporation of Fluoride: Syntheses, Crystal Structures, and Nonlinear Optical Properties of Novel Actinide Fluoroborates
[摘要]：The boric acid flux reactions of uranyl nitrate with sodium, potassium, rubidium, or thallium fluoride result in the formation of a novel family of uranyl(VI) fluoroborate materials. These compounds are Na[(UO(2))B(5)O(8)(OH)F]center dot H(2)O (NaUBOF-1), K[(UO(2))B(5)O(8)(OH)F] (KUBOF-1), K(11)[(UO(2))(6)B(24)O(36)F(22))](H(2)BO(3)) (KUBOF-2), Rb[(UO(2))B(5)O(8)(OH)F] (RbUBOF-1), and Tl[(UO(2))B(5)O(8)(OH)F] (TlUBOF-1). A new neptunium(VI) fluoroborate that is isotypic with NaUBOF-1, Na[(NpO(2))B(5)O(8)(OH)F]center dot H(2)O (NaNpBOF-1), was synthesized via the boric acid flux reaction of neptunium(VI) nitrate with sodium fluoride. These new actinide fluoroborates share a common structural motif consisting of a linear actinyl (U(Np)O(2)(2+)) cation surrounded by BO(3) triangles and BO(4) tetrahedra to create an U(Np)O(8) hexagonal bipyramidal environment around uranium or neptunium. The borate anions bridge between actinyl units to create layers. B-F bonds were formed during the reactions to yield BO(3)F tetrahedral units. The BO(3)F tetrahedra and additional BO(3) triangles extend from the actinyl polyborate layers and are directed approximately perpendicular to the layers. A novel actinyl borate layered topology was found in K(11)[(UO(2))(6)B(24)O(36)F(22))](H(2)BO(3)) (KUBOF-2). Except for K[(UO(2))B(5)O(8)(OH)F] (KUBOF-1) and K(11)[(UO(2))(6)(-) B(24)O(36)F(22))](H(2)BO(3)) (KUBOF-2), all of the other actinide fluoroborate phases adopt noncentrosymmetric space groups. TL[(UO(2))B(5)O(8)(OH)F] (TlUBOF-1), which can be obtained as a pure phase, displays second-harmonic generation of 532-nm light from 1064-nm light.
