Synthesis and Single Crystal Structure of RbEr2Cu3Se5

摘要

Single crystals of a new quaternary rare-earth selenide RbEr2Cu3Se5 have been isolated through the RbCl flux reaction in the RE-Cu-Se system. The title compound crystallizes in an orthorhombic system, space group Cmcm with a = 4.089(2), b = 14.498(6), c = 16.977(2)A, V = 1006.5(7)A3, Z = 4, Dc = 6.63 g/cm3, F(000) = 1720 and (MoKa) = 45.51 mm-1. The final R = 0.0498 and wR = 0.0734 for 1401 observed reflections with I > 3σ(I. The structure of RbEr2Cu3Se5 is a three-dimensional tunnel structure composed of ErSe6 and CuSe4 polyhedra with the charge-balanced Rb+ cations stuffing into the one-dimensional channels along the a direction. In the Er2RbCu3Se5 structure, the [Er2Se(1)4/2Se(2)2Se(3)4/2] double-octahedral chains are linked into a [Er2Cu2Se6] layer in the a-b plane via sharing Se1-Se3 edges with the [Cu(2)2Se(1)2Se(3)4/2] double tetrahedral chains, and [Er2Cu2Se6] layers are further interconnected along the c direction by sharing Se(1)-Se(2) edges with the [Cu(1)Se(1)2Se(2)2/2] tetrahedral chains, forming a three-dimensional framework with the channels along the a axis accommodated by Rb+ ions.