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

Abstract

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]HgSb₂Se₅ (1) (1,2-pda = 1,2-diaminopropane) and [Mn(dien)₂]HgSb₂Se₅ (2) (dien = diethylenetriamine) feature a 1D-[HgSb₂Se₅]_n²ⁿ⁻ ribbon assembled by the {HgSb₂Se₅} groups. The compounds [Ni(en)₃]Hg₂Sb₂Se₆ (3) (en = ethylenediamine) and [Ni(en)(teta)]Hg₂Sb₂Se₆ (4) (teta = triethylenetetramine) feature a 2D-[Hg₂Sb₂Se₆]_n²ⁿ⁻ layer constructed by the combination of the {HgSbSe₃}_n ribbons. The compound [(Me)₂NH₂][Hg₃Sb₃Se₈] (5) contains the dimeric {Sb₂Se₅} groups and {Hg₃SbSe₇}_n layers, which are interconnected into a 3D-[Hg₃Sb₃Se₈]_nⁿ⁻ anionic framework with [(Me)₂NH₂]⁺ ions located in the channels. Furthermore, the comparison between 2 and recently reported [Mn(tren)]HgSb₂Se₅ based on the optical diffuse-reflectance measurements and band structure calculations indicates that the Mn²⁺ ions with different coordination environments make distinct contributions to the CBM of the band structure.