Mild solvothermal syntheses and crystal structures of two quaternary hetero-transition metal sulfides RbAg5HgS4 and CsAgHgS2.

Two quaternary hetero-transition metal sulfides RbAg 5 HgS 4 (1) and CsAgHgS 2 (2) have been successfully synthesized under mild solvothermal method in the presence of thiophenol as a mineralizer. Compound 1 features an interesting 3-D [Ag 5 HgS 4 ]- framework composed of 16-membered ring [Ag (2) 4 M(1) 4 S 8 ] (M ​= ​Ag/Hg) and quasi-8-membered ring [Ag (2) 4 S 4 ] which are all constructed by MS 2 and AgS 2 linear units. Compound 2 possesses anionic [AgHgS 2 ] n n− layers formed with MS 4 (M ​= ​Ag/Hg) tetrahedra, in which Ag+ and Hg2+ ions occupy the same crystallographic site. Particularly, this is the first time that quaternary A-Ag-Hg-S (A ​= ​alkali metal) system were explored via solvothermal method, which demonstrates that structural directing agents have significant influence on the structures of hetero-transition metal sulfides. Furthermore, the XRD experiment and band gap value of compound 2 were also investigated. Two quaternary hetero-transition metal sulfides RbAg 5 HgS 4 (1) and CsAgHgS 2 (2) have been successfully synthesized under mild solvothermal method in the presence of thiophenol as a mineralizer. Compound 1 features an interesting 3-D [Ag 5 HgS 4 ]- framework composed of 16-membered ring [Ag (2) 4 M(1) 4 S 8 ] (M ​= ​Ag/Hg) and quasi-8-membered ring [Ag (2) 4 S 4 ] which are all constructed by MS 2 and AgS 2 linear units. Compound 2 possesses anionic [AgHgS 2 ] n n− layers formed with MS 4 (M ​= ​Ag/Hg) tetrahedra, in which Ag+ and Hg2+ ions occupy the same crystallographic site. [Display omitted] • Two hetero-transition metal sulfides RbAg 5 HgS 4 (1) and CsAgHgS 2 (2) were synthesized solvothermally using thiophenol as a mineralizer. • Compound 1 features a 3-D [Ag 5 HgS 4 ]- framework composed of 16-membered ring [Ag (2) 4 M(1) 4 S 8 ] (M ​= ​Ag/Hg) and quasi-8-membered ring [Ag (2) 4 S 4 ]. • Compound 2 possesses anionic [AgHgS 2 ] n n− layers formed with MS 4 (M ​= ​Ag/Hg) tetrahedra. • The completely different structures of the two sulfides are due to the usage of different structural directing agents. [ABSTRACT FROM AUTHOR]