Syntheses, structures and properties of a series of new lanthanide chalcoarsenates(III) containing crown-shaped [As3Q6]3− (Q = S, Se) clusters

A series of new lanthanide chalcoarsenates(III) [Ln2(tepa)2(μ-OH)2Cl2]3[As3Q6]2 {Q = S, Ln = Eu (Ia), Tm (Ib); Q = Se, Ln = Y (IIa), Sm (IIb), Eu (IIc), Gd (IId), Tb (IIe), Ho (IIf), Er (IIg), Tm (IIh), Yb (IIi); tepa = tetraethylenepentamine} have been synthesized solvothermally and characterized structurally. Both Ia–b and IIa–i are isostructural and contain crown-shaped anions [As3Q6]3− with dinuclear lanthanide [Ln2(tepa)2(μ-OH)2Cl2]2+ cations as counterions. Although a few lanthanide chalcoarsenates have been obtained in the presence of organic chelating amines by solvothermal reaction, their anions are strongly dominated by either noncondensed tetrahedral [AsVQ4]3− or pyramidal [AsIIIQ3]3− moieties. Both Ia–b and IIa–I provide the rare examples of lanthanide chalcoarsenates based on crown-shaped [As3Q6]3− clusters constructed by the condensation of pyramidal [AsIIIQ3]3− moieties. Their optical properties have been characterized by UV–vis spectroscopy, while the photoelectronic and magnetic properties of some compounds are also investigated. This work provides the rare examples of lanthanide chalcoarsenates based on crown-shaped [As3Q6]3− clusters constructed by the condensation of pyramidal [AsIIIQ3]3− moieties. [Display omitted] •A series of new lanthanide chalcoarsenates(III) have been solvothermally synthesized.•The rare examples of lanthanide chalcoarsenates based on crown-shaped [As3Q6]3− clusters.•Compounds IIa–i display good photocurrent responses.