Homochiral and racemic polymorphs show different spin-crossover behaviours due to different intermolecular interactions, and reversible LIESST effects can be realized on homochiral complexes.

Eight members of a new family of polyoxometalate (POM)-ligated organic− inorganic rare earth metal compounds K 11 LiH 21 [RE 3 , Tb (2), Dy (3), Ho (4), Er (5), Tm (6), Yb (7), Lu (8); for compounds 1−6 and 8, n = 46; for compound 7, n = 57; C 6 H 8 O 7 = citric acid) have been synthesized through conventional aqueous solution by introducing organic ligand citric acid into the arsenotungstates system, which were further characterized by elemental analyses, IR and UV spectroscopy, thermogravimetric analyses, and single-crystal X-ray diffraction. The polyoxoanionssubunits linked by another three rare earth ions. What's more, the fluorescence properties of 2 and 3 have also been investigated. Electron paramagnetic resonance (EPR) experiments further demonstrated the result of the interesting photochromic property.

Six tartrate-bridging rare-earth-substituted polytungstoarsenates [RE2(C4H4O6)(C4H2O6)(As W9O33)]2(18-) (Ho(III) (1), Er(III) (2), Tm(III) (3), Yb(III) (4), Lu(III) (5), and Y(III) (6)) have been synthesized under conventional solution conditions. They have been further characterized by elemental analyses, X-ray powder diffraction (XRPD), IR and UV-vis spectroscopy and single-crystal X-ray diffraction. Preliminary variable-temperature magnetic susceptibility measurements indicate that 1-4 exhibit antiferromagnetic coupling.

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Four structurally intriguing members of a new family of lanthanide (Ln)-containing organophosphonate-functionalized polyoxotungstates with the general formula K[Ln(HO)(AsWO)(WO)(OPCOHCHPO)Ln(HO)]·15HO [Ln = Ce (1Ce), Nd (2Nd), Sm (3Sm) and Eu (4Eu)] were directly isolated by controlling the reaction parameters and well established by single-crystal X-ray diffraction, PXRD analyses, IR spectra, elemental analyses, TG and EDX analyses. All the four three-dimensional frameworks consist of the S-shaped inorganic building block {[(AsWO)(WO)]}, two organophosphonate groups {OPCOHCHPO} and four Ln ions. The magnetic properties of the four compounds and the solid-state photoluminescence properties of 2Nd, 3Sm, and 4Eu were also fully investigated.

Solvent molecules are known to have a remarkable effect on the crystal structures and magnetic properties of spin-crossover (SCO) compounds. On the basis of our previous works on this topic, we have synthesized a series of SCO Fe(II) compounds, [Fe(tpa)(NCSe) 2 ]•Solv (tpa = tris(2-pyridylmethyl)amine;and CH 2 Cl 2 for 1•CH 2 Cl 2 ), by crystallization of the molecular complex [Fe(tpa)(NCSe) 2 ] from the respective solvents. Singlecrystal X-ray crystallographic studies show that the molecular packing structures and intermolecular interactions of these compounds are subtly changed by the lattice solvent molecules; thus, their SCO properties can be differentiated from each other. All of the solvated compounds undergo onestep SCO behavior with the order of critical temperatures beingwhich thermal hysteresis loops of 3 K width (T c ↑ = 255 K and T c ↓ = 252 K) and 10 K width (T c ↑ = 256 K and T c ↓ = 246 K) are observed for 1•CH 3 CN-B and 1•CH 2 Cl 2 , respectively.

Thermal- and light-induced SCO behaviors have been studied on two one-dimensional looped coordination polymers.

A homochiral 3D mechanically interlocked framework based on 1D loops is presented, which shows reversible single-crystal-to-single-crystal transformation and enables the interconversion between one-step and two-step spin crossover behaviors.