Novel mercury selenidoantimonates with structures ranging from one-dimensional ribbon to three-dimensional open-framework

摘要

With a transition metal (TM) complex or a protonated organic amine as a structure-directing agent (SDA), five novel Hg-Sb-Se compounds with the architectures ranging from one-dimensional (1D) ribbon, two-dimensional (2D) layer, to three-dimensional (3D) open-framework have been solvothermally synthesized and structurally characterized. The compounds [Ni(1,2-pda) _3]HgSb_2Se_5 (1) (1,2-pda = 1,2-diaminopropane) and [Mn(dien)_2]HgSb_2Se_5 (2) (dien = diethylenetriamine) feature a 1D-[HgSb_2Se_5] n ~(2n-) ribbon assembled by the {HgSb_2Se _5} groups. The compounds [Ni(en)_3]Hg_2Sb _2Se_6 (3) (en = ethylenediamine) and [Ni(en)(teta)]Hg _2Sb_2Se_6 (4) (teta = triethylenetetramine) feature a 2D-[Hg_2Sb_2Se_6]_n ~(2n-) layer constructed by the combination of the {HgSbSe _3}_n ribbons. The compound [(Me)_2NH _2][Hg_3Sb_3Se_8] (5) contains the dimeric {Sb_2Se_5} groups and {Hg3SbSe _7}n layers, which are interconnected into a 3D-[Hg _3Sb_3Se_8]_n ~(n-) anionic framework with [(Me)_2NH_2]~+ ions located in the channels. Furthermore, the comparison between 2 and recently reported [Mn(tren)]HgSb_2Se_5 based on the optical diffuse-reflectance measurements and band structure calculations indicates that the Mn~(2+) ions with different coordination environments make distinct contributions to the CBM of the band structure.