Coordination molecular compounds of cadmium(II) iodide with dimethylpyridines

The reactions of CdI2 with dimethylpyridines (Me2Py is C7H9N) afford complexes CdI2(2,3-Me2Py)2] (I), [CdI2(2,6-Me2Py) (II), and CdI2(3,5-Me2Py)2 (III). The structures of compounds I and II are determined. The crystals of complex I are orthorhombic, space group Pbca, a = 7.930(1) Å, b = 15.537(1) Å, c = 29.943(1) Å, V = 3689.1(5) Å3, ρcalcd = 2.090 g/cm3, Z = 8. The crystals of complex II are monoclinic, space group C2/c, a = 14.784(1), b = 11.991(1), c = 17.711(1) Å, β = 90.39(1)°, V = 1081.1(2) Å3, ρcalcd = 2.908 g/cm3, Z = 4. The structure of compound I is built of discrete neutral complexes [CdI2(2,3-Me2Py)2]. The Cd polyhedron is a distorted tetrahedron (Cd-I 2.289–2.295, Cd-N 2.708–2.734 Å, angles N(I)CdN(I) 103.1°-114.8°). Polymer chains [CdI2(2,6-Me2Py)]∞ extended along the direction [100] are observed due to the bridging iodine atoms in structure II. The Cd polyhedron is a trigonal bipyramid containing iodine atoms at the axial vertices (Cd-Iaks 3.040 Å) and two iodine atoms and the nitrogen atom of the Me2Py ligand in the equatorial plane Me2Py (Cd-Ieq 2.840 Å, Cd-N 2.309 Å). The compounds in the solid state are photoluminescent.