A new polymorph telluridoindate [In(en)3][In5Te9(en)2] with photocatalytic properties

A new polymorph telluridoindate [In(en)3][In5Te9(en)2] (denoted as β-type, en = ethylenediamine) has been solvothermally synthesized and characterized. The crystal data for the β-type are listed as follows: monoclinic, space group Cc (No. 9), a = 11.642(2), b = 20.421(4), c = 17.577(4) Å, β = 92.20(3)°, V = 4175.7(14) Å3, Z = 4. The β-type contains organic-decorated [In4Te9(en)]6 − supertetrahedral cluster and [InTe3(en)]3 − tetrahedron, which are interconnected to form an organic-decorated 2-D telluridoindate layer of [In5Te9(en)23 −]n with 9-membered rings. Two relevant conformers of telluridoindates are compared with each other. The β-type indicates absorption edge at 2.23 eV and exhibits photocatalytic activity for degradation of methyl orange (MO).