Effects of temperature on the crystal and molecular structure of the mixed-valence linear chain bis(ethylenediamine)platinum bis(ethylenediamine)dihaloplatinum tetraperchlorate (halo = chloro, bromo (original) (raw)

1993, Inorganic Chemistry

The crystal structures of the pure monoclinic and orthorhombic phases of [Pt(en)2] [Pt(en)2C12](C104)4 (PtC1) and [Pt(en)2] [Pt(en)~Br2](C104)~ (PtBr), with en = 1,2-diaminoethane, were determined at several temperatures. The monoclinic phase of PtCl has space group E 1 / m , with a = 7.972(3) A, b = 10.874(5) A, c = 8.500(4) A, j3 = 108.91(4)", Z = 2, d = 2.619 g/cm3, and T = -20 "C. The monoclinic phase of PtBr crystallizes in space group P2'/m, with a = 7.959(2) A, b = 10.957(2) A, c = 8.529(2) A, j3 = 109.32(3)", Z = 2, d = 2.811 g/cm3, and T = 25 OC. The orthorhombic phase of PtCl has space group Zbam, with a = 13.594(4) A, b = 9.657(5) A, c = 10.855(4) A, 2 = 4, d = 2.562 g/cm3, and T = 25 OC. The orthorhombic phase of PtBr crystallizes in space group Zbam, with a = 13.671(5) A, b = 9.680(3) A, c = 10.994(3) A, Z = 4, d = 2.712 g/cm3, and T = 40 "C. The monoclinic phases of PtCl and PtBr were also determined at T = -70 and -93 "C, respectively. The lattice constants forPtCl(-70 "C) area = 7.947(4) A, b = 10.871(5) & c = 8.445(5) &and@ = 108.79(4)", and thelatticeconstants for PtBr(-93 "C) are a = 7.912(2) A, b = 10.900(2) A, c = 8.387(2) A, and j 3 = 109.02(3)". The corresponding PtCl and PtBr phases are isostructural. These systems contain chains composed of alternating, octahedral Pt(en)2Xz