Luminescence studies of interacting metal complexes in two dimensions

Tunable Radiationless Energy Transfer in Eu[Au(CN)2]3·3H2O by High Pressure

“…Obviously, the spectral overlap with the 5 L 6 and 5 D 3 absorptions is tuned off or is at least strongly reduced. In this context, it is important to note that the emission intensity is still relatively weak (Figure b) and that its bandwidth is smaller than expected from a comparison to M[Au(CN) 2 ] compounds with no energy transfer. − , An explanation will be given below.…”

“…M[Au(CN) 2 ] compounds (e.g., with M + = K + , Cs + , Tl + ) have been the subject of increasing interest due to their two-dimensional layered structures and their interesting emission properties. − These structures consist of layers of [Au(CN) 2 ] - complexes alternating with layers of M + ions, which are in several cases coordinated with water molecules. − The distances between the gold ions within the layers are relatively short and change with the cation M + . For example, the Au + ions are separated by 3.64 Å (at T = 300 K) for the potassium compound, while the shortest Au−Au separation is only 3.11 Å for M = Cs .…”

“…Indeed, the optical absorption spectrum of the [Au(CN) 2 ] - ion in aqueous solution shows absorption bands only at energies higher than 40 000 cm -1 , while the M[Au(CN) 2 ] crystals have their absorption bands shifted to lower energies by as much as 20 000 cm -1 (e.g., see refs and ). These shifts are ascribed in a first approximation to the formation of electronic energy bands, and the resulting band gap is energetically strongly lowered compared to the HOMO−LUMO separation of the complexes. ,, In addition, exciton effects are also important and strongly determine the properties of the low-lying energy states , …”

Hydrothermal synthesis, structural, Raman, and luminescence studies of Am[M(CN)2]3·3H2O and Nd[M(CN)2]3·3H2O (M=Ag, Au): Bimetallic coordination polymers containing both trans-plutonium and transition metal elements

“…The association usually extends to yield larger oligomers and one-or two-dimensional polymers. In general terms, ''aurophilic'' bonding of this type is now widely accepted as the most prominent example of a general phenomenon of metallophilicity, and is recognized as a major factor in determining supramolecular structures and properties [16][17][18]. Hence, the chemistry of Au(I) is satiated with systems that are polymeric by virtue of these Au-Au interactions.…”

“…Hence, the chemistry of Au(I) is satiated with systems that are polymeric by virtue of these Au-Au interactions. In this regard, the linear building block dicyanoaurate, [Au(CN) 2 ] À , is a convenient unit with which to explore the use of aurophilicity as a supramolecular design element [16][17][18][19][20]. This simple anion has been extensively studied over the years due it its ability to form coordination polymers through cyanide bridging.…”