International audienceReactions in water between lanthanide chlorides and the disodium salt of 5-methoxyisophthalic acid, Na2(mip)·7H2O, lead to the first three series of lanthanide-based coordination polymers based on this ligand. The first series contains only one compound with chemical formula [Ce(mip)3/2(H2O)5·2H2O]∞. The second series has general chemical formula [Ln(mip) (Hmip)(H2O)5·H2O]∞ with Ln = La–Ce. The last family is constituted by compounds with general chemical formula [Ln2(mip)3(H2O)8·4H2O]∞ with Ln = Sm–Er plus Y. Luminescent properties of the compounds that belong to this family have been studied. The Tb-based compound presents one of the brightest luminescences reported to date for a lanthanide-based coordination polymer. The weak intermetallic energy transfer evidenced on the third family of compounds allows easy and predictable color modulation of the heterobimetallic powders through additive colors strategy

We report the study of a Dy-based metal-organic framework (MOF) with unprecedented magnetic properties. The compound is made of nine-coordinated Dy magnetic building blocks (MBBs) with poor intrinsic single-molecule magnet behavior. However, the MOF architecture constrains the MBBs in a one-dimensional structure that induces a ferromagnetic coupling between them. Overall, the material shows a magnetic slow relaxation in absence of external static field and a hysteretic behavior at 0.5 K. Low-temperature magnetic studies, diamagnetic doping, and ab initio calculations highlight the crucial role played by the Dy-Dy ferromagnetic interaction. Overall, we report an original magnetic object at the frontier between single-chain magnets and single-molecule magnets that host intrachain couplings that cancel quantum tunneling between the MBBs. This compound is evidence that a bottom-up approach through MOF design can induce spontaneous organization of MBBs able to produce remarkable molecular magnetic materials.

The CDIFX of Rennes is acknowledged for single crystal X-ray diffraction data collection.International audienceReactions in water between lanthanide chlorides and the di-sodium salt of 1,2-phenylenediacetic acid, Na2(o-pda), lead to two families of coordination polymers with respective chemical formulae [La2(o-pda)3(H2O)4,4H2O]∞ (1) and [Ln2(o-pda)3(H2O)2,2H2O]∞ (2) for Ln = Ce-Nd, Sm-Lu and Y. Compound 1 crystallises in the monoclinic system, space group C2/c (n°15), with a = 28.195(5) Å, b = 12.2305(3) Å, c = 8.7607(1) Å, β = 98.835(1)° and Z = 4. Its crystal structure and thermal properties are described. Compounds of family 2 are isostructural to a previously reported crystal structure. Luminescence properties of Eu- and Tb-based compounds have been studied

Reaction in gel between the sodium salt of 1,4-phenylenediacetic acid (Na2C10O4H8–Na2 p-pda) and lanthanum chloride yields single crystals of the three-dimensional coordination polymer poly[[tetraaquatris(μ-1,4-phenylenediacetato)dilanthanum(III)] octahydrate], {[La2(C10H8O4)3(H2O)4]·8H2O}∞. The LaIII coordination polyhedron can be described as a slightly distorted monocapped square antiprism. One of the two p-pda2− ligands is bound to four LaIII ions and the other to two LaIII ions. Each LaIII atom is coordinated by five ligands, thereby generating a metal–organic framework with potential porosity properties.

Ferromagnetic interactions induced by metal—organic framework (MOF) architecture turn a poor single‐molecule magnet (SMM) into a slow relaxing material. The MOF is made of nine‐coordinated DyIII magnetic building blocks (MBBs) with poor intrinsic SMM behavior. However, the MOF architecture constrains the MBBs in a one‐dimensional structure that induces a ferromagnetic coupling between them. More information can be found in the Full Paper by B. Le Guennic, K. Bernot et al. on page 6983.