Reduction of structural dimensionality through incorporation of auxiliary ligands in lanthanide tetracyanoplatinates

Lanthanide Photoluminescence in Heterometallic Polycyanidometallate-Based Coordination Networks

Solid-state functional luminescent materials arouse an enormous scientific interest due to their diverse applications in lighting, display devices, photonics, optical communication, low energy scintillation, optical storage, light conversion, or photovoltaics. Among all types of solid luminophors, the emissive coordination polymers, especially those based on luminescent trivalent lanthanide ions, exhibit a particularly large scope of light-emitting functionalities, fruitfully investigated in the aspects of chemical sensing, display devices, and bioimaging. Here, we present the complete overview of one of the promising families of photoluminescent coordination compounds, that are heterometallic d–f cyanido-bridged networks composed of lanthanide(3+) ions connected through cyanide bridges with polycyanidometallates of d-block metal ions. We are showing that the combination of cationic lanthanide complexes of selected inorganic and organic ligands with anionic homoligand [M(CN)_x]ⁿ⁻ (x = 2, 4, 6 and 8) or heteroligand [M(L)(CN)₄]²⁻ (L = bidentate organic ligand, M = transition metal ions) anions is the efficient route towards the emissive coordination networks revealing important optical properties, including 4f-metal-centred visible and near-infrared emission sensitized through metal-to-metal and/or ligand-to-metal energy transfer processes, and multi-coloured photoluminescence switchable by external stimuli such as excitation wavelength, temperature, or pressure.

Magnetostructural characterization of copper(II) hydroxide dimers and coordination polymers coordinated to apical isothiocyanate and cyanide-based counteranions

Five Cu(II) hydroxo-bridged complexes of the type [Cu2(μ-OH)2(L)2][A]x·yH2O (where L = 1,10-phenanthroline, A = NCS–, x = 2, y = 2 (1); L = 2,2′-bipyridine, A = NCS–, x = 2, y = 1 (2); L = 2,2′-bipyridine, A = [Au(CN)4]–, x = 2, y = 0 (3) and 2 (4); L = N,N,N′,N′-teteramethylethylenediamine, A = [Pt(SCN)4]2–, x = 1, y = 0 (5)) have been prepared and have been characterized by elemental analysis, IR and Raman spectroscopy, X-ray crystallography, and SQUID magnetometry. Complexes 1 and 2 consist of five-coordinate Cu(II) hydroxo-bridged dinuclear units bound to two NCS– anions in the apical positions, 3 and 4 are pseudo-polymorphs of a Cu(II) hydroxo-bridged dimer core with [Au(CN)4]– counteranions, and 5 is a coordination polymer of Cu(II) hydroxo-bridged dimers with trans-bridging [Pt(SCN)4]2– anions coordinated in the apical position of the five-coordinate Cu(II) centres. The magnetic susceptibility versus temperature for each system was measured, fit to obtain J-coupling values (which range from –0.37 to 17.8 cm−1), and qualitatively compared to known magnetostructural correlation parameters.