A new series of lanthanide-containing dicyanoaurate coordination polymers, [(n)Bu(4)N](2)[Ln(NO(3))(4)Au(CN)(2)] (Ln = Nd, Eu, Gd or Tb), were synthesized and structurally characterized. They form an isomorphous series, crystallizing in the space group I2(1)2(1)2(1). 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)·3H(2)O. Unlike the Ln[Au(CN)(2)](3)·3H(2)O 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.

The new lanthanide-dicyanoaurate coordination polymers [BuN][Ln(NO)Au(CN)] (Ln = Sm, Dy) and Sm[Au(CN)]·3HO were prepared and structurally characterized and their luminescence spectra described. The emissions of solid-solutions of [BuN][Ln(NO)Au(CN)] (Ln = Ce, Sm, Eu, Tb, and Dy) were explored with an emphasis on their capacity for luminescent color tuning and white-light emission via the selection of composition, excitation wavelength, and temperature. Specifically, the binary solid-solutions [BuN][CeDy(NO)Au(CN)] and [BuN][SmTb(NO)Au(CN)], and the ternary solid-solutions [BuN][CeSmTb(NO)Au(CN)] and [BuN][CeEuTb(NO)Au(CN)], were prepared and examined in terms of suitability for color-tuning capacity. These results showcase that the emission from the [BuN][Ln(NO)Au(CN)] framework has the capacity to be tuned to extremes corresponding to deep reds (CIE coordinates 0.65, 0.35), greens (0.28, 0.63), and deep blue/violet (0.16, 0.06) as well as white (0.31, 0.33). Conversely, the emission of the Sm[Au(CN)]·3HO framework, when doped with the green phosphor Tb(III), changes only slightly because of the predominantly Au(I)-based emission and Sm(III) → Au(I) energy transfer.

This investigation is focused on comparing photophysical properties between two series of lanthanide-dicyanoaurate coordination polymers that contain and lack aurophilic interactions, respectively. Luminescence and crystallographic studies have been carried out on five different coordination polymer chain frameworks: the non-aurophilic [(n)Bu4N]2[LnxGd1-x(NO3)4Au(CN)2] (Ln = Eu, Tb; x = 0.01, 0.02, 0.04, 0.08) and[(n)Bu4N]2[EuxTb1-x(NO3)4Au(CN)2] (x = 0.25, 0.5, 0.75), as well as the analogous solid-solutions of aurophilic LnxGd1-x[Au(CN)2]3·3H2O and EuxTb1-x[Au(CN)2]3·3H2O. The single-crystal structures of M[Au(CN)2]3 ·3H2O (M = Eu, Gd) are also reported for comparison. In the aurophilic frameworks the close proximity of gold(I) centers on neighboring chains allows for Au-Au interactions to take place that facilitate energy transfer between lanthanides. Terbium- and europium-doped aurophilic frameworks show energy transfer between one of the lanthanide ions and dicyanoaurate centers as observed via luminescence measurements. In the non-aurophilic frameworks the [(n)Bu4N] cations separate the Au-Au chains, thereby preventing interaction between them, and preventing energy transfer. By preparing the aurophilic EuxTb1-x[Au(CN)2]3·3D2O frameworks, it was shown that the O-H vibrational energy in the hydrated (aurophilic) samples can partially quench the Ln signal.

The concept that hydrogen bonding cations can reduce the coulombic repulsion inherent to anionic gold species and thereby trigger aurophilicity is realized with three new photoluminescent compounds of the form [Q]2[Au2(i-mnt)2] (i-mnt = (CN)2C[double bond, length as m-dash]CS2(2-), Q = 3,5-dimethylpyrazolium, piperidinium). These compounds illustrate unprecedented supramolecular aurophilicity between the anions, the emission of which is significantly red-shifted compared to zero-dimensional analogues, a direct result of the aurophilic network. The piperidinium salt exhibits a vapochromic/luminescent response to ammonia, inducing a change in colour of the reflectance and emission from red to yellow. These results demonstrate the ability to rationally control the formation of supramolecular metallophilic networks via the incorporation of hydrogen bonding cations.

New members of the Ln[Au(CN) 2 ] 3 ·3H 2 O and [nBu 4 N] 2 [Ln(NO 3 ) 4 Au(CN) 2 ] series Ln = Ce (CeAu 3 and CeAu respectively) are reported herein where their synthesis, structure and photoluminescence properties are discussed. The first is a 3-D coordination polymer with aurophilic interactions of 3.35 Å and the latter is a 1-D coordination polymer that lacks them. At 293 K both CeAu 3 and CeAu display characteristic Ce III -based emission at λ max = 393 nm (5d→ 2 F J ), however in CeAu 3 Au I -