Structure of Dibromo(1,2-diaminoethane)palladium(IV)-bis(1,2-diaminoethane)- palladium(II) Tetrakisperchlorate, [Pd(en)2Br2][Pd(en)2](ClO4)4

Abstract

Orthorhombic [Pd(C2H8N2)2Br2][Pd(C2H8N2)][ClO4]4, C8H32Br2Cl4N8O16Pd2, Mr = 890.42, crystallizes in space group Iba2, a = 9.651(2), b = 13.951(8), c = 10.771(2) Å, Z = 2, V = 1412.80 Å3, dc = 2.05 g cm-3, R = 0.0564 for 1545 unique reflections. Data collection: MoKα, λ = 0.71069 Å, room temperature. The structure is a typical Wolffram’s Salt Analogue (WSA) with infinite stacks of planar [Pd(en)2]2+,4+ complex cations bridged by bromides. The ligands are three-dimensionally ordered. Intra-chain and inter-chain hydrogen bridges link the ligands with the perchlorate counter ions which occupy statistically two different orientations. Diffuse sheets appear together with Bragg reflections for 1 odd layers indicating a thermally activated motion of the bromides in chain direction. This model was confirmed with temperature dependent Weissenberg work