Heterobimetallic lanthanide–gold coordination polymers: structure and emissive properties of isomorphous [nBu4N]2[Ln(NO3)4Au(CN)2] 1-D chains

Abstract

A new series of lanthanide-containing dicyanoaurate coordination polymers, [nBu4N]2[Ln(NO3)4Au(CN)2] (Ln = Nd, Eu, Gd or Tb), were synthesized and structurally characterized. They form an isomorphous series, crystallizing in the space group I212121. The structure is composed of a one dimensional zigzag of Ln–N–C–Au–C–N–Ln chains with no intra- or inter-chain aurophilic interactions. The series is related to and can be described as a reduced dimensionality analogue of the previously studied Ln[Au(CN)2]3·3H2O. Unlike the Ln[Au(CN)2]3·3H2O series, there is no efficient energy transfer between dicyanoaurate and the lanthanide metal centers in the complexes and they essentially act as two separate emissive chromophores.