Discrete and polymeric iodoplumbates with Pb3I10 building blocks: [Pb3I10]4−, [Pb7I22]8−, [Pb10I28]8−, 1∞[Pb3I10]4− and 2∞[Pb7I18]4−

Abstract

Iodoplumbate complexes were obtained by reaction of PbI₂ with sodium iodide in polar organic solvents and precipitation with large cations. With diammonium cations [R₃N(CH₂)_nNR₃]²⁺ a series of polynuclear iodoplumbates could be isolated and characterized by single crystal X-ray diffraction. While [Bu₃N(CH₂)₄NBu₃]₂[Pb₃I₁₀] 1, [Bu₃N(CH₂)₄NBu₃]₄[Pb₇I₂₂] 2 and [Bu₃N(CH₂)₄NBu₃]₄[Pb₁₀I₂₈] 3 contain discrete anions, the iodoplumbates [Me₃N(CH₂)₅NMe₃]₂[Pb₃I₁₀] 4 and [Pr₃N(CH₂)₅NPr₃]₂[Pb₇I₁₈] 5 consist of one-dimensional and two-dimensional co-ordination polymers, respectively. The [Pb₃I₁₀]^4– anion in 1 can be regarded as a building block for the structures of 2, 4, 5 and, slightly modified, of 3. In spite of their related structures and similar compositions, these complexes are formed selectively and in good yield under appropriate reaction and crystallization conditions.