Synthesis and crystal structure analysis of Sr8Cu3In4N5 and Sr0.53Ba0.47CuN

Single crystals of new quaternary compounds Sr8Cu3In4N5 and Sr0.53Ba0.47CuN were prepared, respectively, from a Sr-Cu-In-Na melt under 7 MPa of N2 and from a Sr-Ba-Cu-In-Na melt under 0.5 MPa of N2 by slow cooling from 1023 to 823 K. The crystal structures were determined by single-crystal X-ray diffraction. Sr8Cu3In4N5 has an orthorhombic structure (space group, Immm, Z=2, a=3.8161(5) A, b=12.437(2) A, c=18.902(2) A), and is isostructural with Ba8Cu3In4N5. It contains nitridocuprates of isolated units 0[CuN2] and one-dimensional linear chains ∝1[CuN2/2] and one-dimensional indium clusters ∝1[In2In2/2]. Sr0.53Ba0.47CuN crystallizes in an orthorhombic cell, space group Pbcm, Z=4, a=5.4763(7) A, b=9.2274(12) A, c=9.0772(12) A. The structure contains infinite zig-zag chains ∝1[CuN2/2] which kink at every second nitrogen atom