AMTeS3 (A=K, Rb, Cs; M=Cu, Ag) : a new class of compounds based on a new polychalcogenide anion, TeS32-

The reaction of Cu or Ag with mixed polychalcogenide flux A 2 S x Te y (A=K, Rb, Cs) yielded RbCuTeS 3 (1), CsCuTeS 3 (2), α-KAgTeS 3 (3), β-KAgTeS 3 (4), RbAgTeS 3 (5), and CsAgTeS 3 (6) possessing new structure types. Compounds 1, 4, 5, and 6 are two-dimensional and isostructural. They crystallize in the monoclinic space group P2 1 /c, with a=7.434(3) A, b=10.526(3) A, c=8.234(3) A, β=106.13(3) o , V= 619.0(7) A 3 for 1; a=7.340(2) A, b==10.647(2) A, c=8.504(2) A, β=106.46(2) o , V= 637.4(3) A 3 for 4; a=7.566(8) A, b=10.724(8) A, c=8.586(9)A, β=106.36(8) o , V=668(2) A 3 for 5; and a=7.832(6) A, b=10.803(7) A, c=8.668(8) A, β=705(2) A 3 for 6