Solvothermal Syntheses And Characterizations Of Organic Hybrid Selenidogermanates

New chalcogenidogermanate materials are of interest,due to rich structural diversity and potential applications in technological areas,such as magnetism materials,photocatalytic processes,semiconductor,nonlinear optical materials and the others,so that researchers have an interest in chalcogenidogermanate materials.In order to develop the potential application of new kind of chalcogenidogermanate,seventeen organic hybrid selenidogermanates have been synthesized and structurally characterized by single crystal X-ray diffraction,powder X-ray diffraction,elemental analysis,IR,UV-vis,thermogravimetric analysis.The magnetism,luminescent,thermal stabilities,and photocatalysis of some compounds were further investigated.Lanthanoid selenidogermanates:A series of lanthanoid selenidogermanates（H₂peha）[Ln₂（tepa）₂（μ-OH）₂Cl₂]{[Ln₂（tepa）₂（μ-OH）₂Cl]₂（μ-Ge₂Se₆）}[Ge₂Se₆]Cl₂[Ln=Y（1）,Er（2）;[Sm₂（tepa）₂（μ-OH）₂（μ-Ge₂Se₆）]_n（3）,[Ho₂（tepa）₂（μ-OH）₂（μ-Ge₂Se₆）]_n（4）,[Ce₄（tepa）₄（μ-GeSe₄）（μ-GeSe₅）（μ-Ge₂Se₆）]_n（5）,[Ln₂（tepa）₂（μ-OH）₂（μ-Ge₂Se₆）]_n·xnH₂O[Ln=Tb（6）,x=0.5;Ln=Tm（7）,x=0]（H₃O）[Tm（teta）₂][Ge₂Se₆]（8）and[Ln（teta）（tren）Cl]₂[Ge₂Se₆]（en）{Ln=Pr（9）,Nd（10）,Sm（11）,Eu（12）,Gd（13）,Tb（14）}were solvothermally prepared and structurally characterized.The structures of compounds 1-2 contain protonated H₂peha²⁺ion,complex cation[Ln₂（tepa）₂（μ-OH）₂Cl₂]²⁺,[Ge₂Se₆]^4-anion,free Cl^-ions,and{[Ln₂（tepa）₂（μ-OH）₂Cl]₂（μ-Ge₂Se₆）}²⁺cation constructed by two unsaturated[Ln₂（tepa）₂（μ-OH）₂Cl]³⁺groups connecting via the trans terminal Se atoms of[Ge₂Se₆]^4-anion,which provides the first example of organic decorated lanthanoid selenidogermanate cation.Both compounds 3-4 and 6-7 contain 1-D neutral[Ln₂（tepa）₂（μ-OH）₂（μ-Ge₂Se₆）]_n chains constructed by the linkages of unsaturated complex[Ln₂（tepa）₂（μ-OH）₂]⁴⁺cations and[Ge₂Se₆]^4-anions,but their stacking patterns of neutral chains are different.Compound 5 consists of 1-D neutral[Ce₄（tepa）₄（μ-GeSe₄）（μ-GeSe₅）（μ-Ge₂Se₆）]_nchain,wherethreedifferent selenidogermanate anions act as bridging ligands to link unsaturated[Ce（tepa）]³⁺ions.Compound 5 represents the first example of the coexistence of three different selenidogermanate anions in the same framework.Compound 8 contains isolated[Tm（teta）₂]³⁺ions,protonated H₃O⁺ions and dimeric[Ge₂Se₆]^4-anions,while 9-14 are composed of[Ln（teta）（tren）Cl]³⁺ions,dimeric[Ge₂Se₆]^4-anions and free en molecules.The optical properties of all compounds have been characterized by UV-vis spectra,and magnetic properties of compounds 1-7 have also been investigated.Compound 9 was calculated the band structures and density of states.Lanthanoid thiogermanates:Both compounds 15 and 16 are isostructural.The Ln³⁺ion is in a distorted bi-capped trigonal prism,which is formed by five N atoms of one tepa ligand,two O atoms of–OH groups and one S of one[μ-Ge₂S₆]^4-anion.Compounds 15 and 16 contain 1-D neutral chains[Ln₂（tepa）₂（μ-OH）₂（μ-Ge₂Q₆）]_n based on the linkages of[Ln₂（tepa）₂（μ-OH）₂]⁴⁺cations and[μ-Ge₂Q₆]^4-anions.The 1-D neutral chains of 15 and 16 are arranged in a crossing manner.Their band gaps in the range of3.31-3.35 eV are derived from optical absorption spectra.Cuprousthiogermanate:Anovel3-Dcuprousthiogermanate[H₄teta][Cu₈Ge₃S₁₂]·0.5（teta）（17,teta=triethylenetetramine）has been solvothermally synthesized and structurally characterized.The crystal structure of 17 is built up from a rare 3-D[Cu–S–Cu]_n network and entrapped[GeS₄]tetrahedra.This 3-D[Cu–S–Cu]_n network is constructed by the linkages of icosahedral[Cu₈S₁₂]clusters and[Cu₈S₁₆]rings.17 represents the first example of 3-D cuprous thiogermanate based on 3-D inorganic[Cu–S–Cu]_n network.The absorption edge of 17 is 2.45 eV,exhibiting properties of the semiconductor.17 has shown photocatalytic activity for degradation of methylene blue（MB）under visible light.