A series of end-to-end azido-bridged per- ovskite-type compounds ((CH3)nNH4−n)(Mn(N3)3 )( n = 1−4) were synthesized and characterized. Structural phase transitions indicating the general lattice flexibility were observed and confirmed by the crystal structures of different phases. These materials show cation-dependent magnetic ordering at up to 92 K and magnetic bistability near room temperature.

Cation-Dependent Magnetic Ordering and Room-Temperature Bistability in Azido-Bridged Perovskite-Type Compounds

Polynitrile anions as ligands: From magnetic polymeric architectures to spin crossover materials

Molecular magnets Cu(hfac)2LR represent a new type of photoswitchable materials based on exchange-coupled clusters of copper(II) with stable nitroxide radicals. It was found recently that the photoinduced spin state of these compounds is metastable on the time scale of hours at cryogenic temperatures, similar to the light-induced excited spin state trapping phenomenon well-known for many spin-crossover compounds. Our previous studies have shown that electron paramagnetic resonance (EPR) in continuous wave (CW) mode allows for studying the light-induced spin state conversion and relaxation in the Cu(hfac)2LR family. However, light-induced spin dynamics in these compounds has not been studied on the sub-second time scale so far. In this work we report the first time-resolved (TR) EPR study of light-induced spin state switching and relaxation in Cu(hfac)2LR with nanosecond temporal resolution. To enhance spectral resolution we used high-frequency TR EPR at W-band (94 GHz). We first discuss the peculiarities ...

W-band time-resolved electron paramagnetic resonance study of light-induced spin dynamics in copper-nitroxide-based switchable molecular magnets.

Syntheses, Characterization, and Properties of Rhenium(I) Tricarbonyl Complexes with Tetrathiafulvalene-Fused Phenanthroline Ligands

Molecular magnets Cu(hfac)2LR (hfac = hexafluoroacetylacetonate) called “breathing crystals” exhibit thermally and light-induced magnetic anomalies very similar to iron(II) spin-crossover compounds...

Self-Decelerating Relaxation of the Light-Induced Spin States in Molecular Magnets Cu(hfac)2LR Studied by Electron Paramagnetic Resonance

An original magnetic bistability and a thermochromic transition are observed in a new CuII molecular chain. Thermal structural studies reveal changes in the CuII coordination sphere, driven by a more pronounced Jahn−Teller effect at low temperature. These distortions provoke a gradual color change. The structural study at 10 K shows a dimerization of the molecular chain, in agreement with the abrupt magnetic transition observed at 30 K.

Eliseo Ruiz

Papers

Magnetic Bistability and Thermochromism in a Molecular CuII Chain