[Mn(en)3]CdSnTe4 and [Mn(en)3]Ag6Sn6Te8:: New intermetallic tellurides synthesized in superheated organic medium

Two intermetallic tellurides, Mn(en)(3)]CdSnTe4 (I) and [Mn(en)(3)]Ag6Sn2Te8 (II), have been synthesized in superheated ethylenediamine solutions at 180 degrees C. Single-crystal X-ray diffraction analyses show that I crystallizes in triclinic crystal system, space group P1. (No. 1) with lattice parameters a = 9.134(2) Angstrom, b = 10.085(3) Angstrom, c = 12,691(3)Angstrom, alpha = 73.52(2)degrees, beta = 86.05(2)degrees, gamma = 76.43(2)degrees, V = 1089.7(5) Angstrom(3), and Z = 2 and II belongs to trigonal (rhombohedral) crystal system, space group R (3) over bar m (No. 166) with a = 8.9590(9) Angstrom, c = 34.795(2) (2) Angstrom, V = 2418.6(4) Angstrom(3), and Z = 3. Both compounds possess new structure types. The structure of I is composed of one-dimensional Zintl chains of alternating edge-sharing MTe4 (M = Cd, Sn) tetrahedra and [Mn(en)(3)](2+) complex, cations that are between the chains. The structure of II contains two-dimensional double layers of Ag6Sn2Te82- formed by connecting two single honeycomb-like layers through M-Te bonds (M = Ag, Sn), The double layers are separated by the [Mn(en)(3)](2+) templates. Optical diffuse reflectance measurements have been performed on the powder samples of I and II and have suggested that both compounds are semiconductors with band gaps of 1.75 and 0.77 eV, respectively.