Synthesis and molecular and crystal structure of K4.5{[Mo3(μ3-Te)(μ2-Te2)3(CN)6]I}I1.5•3H2O and Cs3{[Mo3(μ3-Te)(μ2-Te2)3(CN)6]I}•2H2O

Crystal structures of two new compounds containing trigonal tellurium-bridged cluster fragments [Mo-3(mu (3)-Te)(mu (2-)-Te-2)(3)](4+) were investigated. Crystal data for K-4.5{[Mo-3(mu (3)-Te)(mu (2)-Te-2)(3)(CN)(6)]I}I-1.5.3H(2)O: space group P3c1, Z = 4, a = 13.280(1), c = 23.800(3) Angstrom, V = 3635.0(6) Angstrom (3), d(calc) = 3.432 g/cm(3), R-1 = 0.0335, wR2 = 0.0912 for 1378 I-hkl>2 sigma (1) from 3545 meausred I-hkl; for Cs-3{[Mo-3(mu (3)-Te)(mu (2)-Te-2)(3)(CN)(6)]I}.2H(2)O: space group P2(I)/n, Z = 2, a = 9.650(2), b = 22.297(5), c = 27.446(7) Angstrom, beta = 94.10(2)degrees, V = 5890(2) Angstrom (3), d(calc) = 4.273 g/cm(3), R-1 = 0.0384, wR(2) = 0.0744 for 957 I-hkl>2 sigma (I) from 3758 measured I-hkl (Enraf-Nonius CAD-4 diffractometer, lambda MoKalpha, graphite monochromator). In both compounds, ionic pairs {[Mo3Te7(CN)(6)]I}(3-) with Te-ax...Gamma distances of 3.358-3.676 Angstrom are formed. In the potassium salt, the {[Mo3Te7(CN)(6)]I}(3-) anion pairs are linked by the additional Te-eq...Gamma short contacts of 3.460 Angstrom into two-dimensional corrugated layers perpendicular to the c axis of the unit cell. The structure of the cesium salt is ionic with interstitial H2O molecules and double-layer closest packing of anions.