Hydrothermal syntheses, crystal structures, and optical properties of transition metal selenidostannates

Abstract

New organic–inorganic hybrid selenidostannates [{Mn(2,2′-bipy)₂}₂(µ₂-Sn₂Se₆)] (1) and [TM(2,2′-bipy)₃]₂[Sn₃Se₇]₂·(2,2′-bipy)·H₂O (TM = Co (2), Ni (3); 2,2′-bipy = 2,2′-bipyridine) were prepared under hydrothermal conditions. In 1, two edge-sharing [SnSe₄] tetrahedra condense to form a dimeric [Sn₂Se₆]^4– unit. The [Sn₂Se₆]^4– unit is a tetradentate chelating ligand via four terminal Se atoms to join two unsaturated [Mn(2,2′-bipy)₂]²⁺ complexes, forming a neutral complex [{Mn(2,2′-bipy)₂}₂(µ₂-Sn₂Se₆)]. Compounds 2 and 3 consist of extended [Sn₃Se₇]^2– selenidostannate anions, octahedral [TM(2,2′-bipy)₃]²⁺ complex cations, and 2,2′-bipy and H₂O molecules. The structural features of 2 and 3 are coexistence of both 1-D${}_{\infty }{}^1[S{n}_{3}S{e}_7{}^{2-}]$ and 2-D${}_{\infty }{}^2[S{n}_{3}S{e}_7{}^{2-}]$ polymeric anions. The 1-D${}_{\infty }{}^1[S{n}_{3}S{e}_7{}^{2-}]$ chain is constructed by interconnection of the secondary building units (SBUs) Sn₃Se₉ via sharing two Se atoms, while the 2-D${}_{\infty }{}^2[S{n}_{3}S{e}_7{}^{2-}]$ layer is constructed by Sn₃Se₁₀ SBUs via sharing three Se atoms. Compounds 1–3 exhibit narrow semiconducting band gaps varying in the range of 1.95–2.14 eV. Compound 2 displays higher photocatalytic activity than 1 on the degradation of crystal violet in water under visible irradiation.

Graphical Abstract

Keywords:

• Selenidostannates
• hydrothermal syntheses
• optical properties
• photocatalytic properties

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (No. 21171123).