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We here present how rebalancing the interplay between H-bonds and dispersive forces (Van der Waals/π-π stacking) may induce or not the generation of kinetic metastable states. In particular, we show that extending the aromatic content and favouring the interchain VdW interactions causes a delay into the cooperative supramolecular polymerization of a new family of toluene bis-amide derivatives by trapping the metastable inactive state., (© 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

A dinuclear metallacycle assembled from a bispyridyl dithienylethene linker and a highly anisotropic dysprosium based Single Molecule Magnet (SMM) shows magnetic hysteresis at 1.8 K together with photoisomerization in single crystals (SC). The impact of photoswitching on the SMM behavior is evidenced and related to the specific organization of the magnetic units.

In this study we demonstrate that single-chain magnets (SCMs) can be assembled in gel phase and transferred intact on surface. We take advantage of a family of SCMs based on Tb III ions and nitronyl-nitroxides radicals functionalized with short alkyl chains known to form crystalline supramolecular nanotubes interacting with heptane acting as crystallizing solvent. When the radicals are functionalized with long aliphatic chains a robust gel is formed with similar structural and functional properties respect to its crystalline parent. Indeed, a small-angle X-ray scattering (SAXS) study unambiguously demonstrates that the gel is made of supramolecular nanotubes: the high stability of the gel allows the determination from SAXS data of precise nanotube metrics such as diameter, helical pitch and monoclinic cell of the folded 2D crystal lattice along the tube direction. Additionally, static and dynamic magnetic investigations show the persistence of the SCM behavior in the metallogel. Last, on-surface gelation provides thick films as well as sub-monolayer deposits of supramolecular nanotubes on surface as evidenced by atomic force microscopy (AFM) observations. This paves the road toward magnetic materials and devices made of SCMs profiting of their isolation on surface as individual chains.

The careful monitoring of crystallization conditions of a mixture made of a Tb III building block and a substituted nitronyl-nitroxide that typically provides infinite coordination polymers ( chains ), affords a remarkably stable linear hexanuclear molecule made of six Tb III ions and five NIT radicals. The hexanuclear units are double-bridged by water molecules but ab initio calculations demonstrate that this bridge is inefficient in mediating any magnetic interaction other than a small dipolar antiferromagnetic coupling. Surprisingly the hexanuclears , despite being finite molecules, show a single-chain magnet (SCM) behavior. This results in a magnetic hysteresis at low temperature whose coercive field is almost doubled when compared to the chains . We thus demonstrate that finite linear molecules can display SCM magnetic relaxation, which is a strong asset for molecular data storage purposes because 1D magnetic relaxation is more robust than the relaxation mechanisms observed in single-molecule magnets (SMMs) where under-barrier magnetic relaxation can operate., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Reactions in water of lanthanide chlorides with the sodium salt of 4,5-dichlorophthalate (dcpa 2- ) lead to two families of isostructural coordination polymers: family F1 that gathers compounds with the general chemical formula [Ln 2 (dcpa) 3 (H 2 O)] ∞ with Ln = La-Gd (except Pm) and family F2 that gathers compounds with general chemical formula [Ln 2 (dcpa) 3 (H 2 O) 5 ·3H 2 O] ∞ with Ln = Tb-Lu plus Y. Heterolanthanide molecular alloys that contain both Eu 3+ and Tb 3+ ions have been prepared in both structural families. Their luminescence properties have been studied, especially from the brightness point of view. This study revealed that structural family F1 provides molecular alloys that are much more luminescent than those of structural family F2 . Therefore, a phase-induction strategy was followed that allowed the design of some molecular alloys (La/Tb/Eu and La/Dy) that are, to the best of our knowledge, among the most luminescent coordination polymers reported so far. This study opens the way to bright luminescent bar codes as well as to bright white luminescent lanthanide-based coordination polymers.

We report a single-chain magnet (SCM) made of a terbium(III) building block and a nitronyl-nitroxide radical (NIT) functionalized with an aliphatic chain. This substitution is targeted to induce a long-range distortion of the polymeric chain and accordingly it gives rise to chains that are curled with almost 20 nm helical pitch. They self-organize as a chiral tubular superstructure made of 11 chains wound around each other. The supramolecular tubes have a 4.5 nm internal diameter. Overall, this forms a porous chiral network with almost 44 % porosity. Ab initio calculations highlight that each Tb III ion possesses high magnetic anisotropy. Indeed, notwithstanding the supramolecular arrangement each chain behaves as a SCM. Magnetic relaxation with both finite and infinite-size regimes is observed and confirms the validity of the Ising approximation. This is associated with quite strong coercive field and magnetic remanence (H c =2400 Oe M R =2.09 μ B at 0.5 K) for this class of compounds., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The terbium(III) ion is a particularly suitable candidate for the creation of surface-based magnetic and luminescent devices. In the present work, we report the epitaxial growth of needle-like objects composed of [Tb(hfac) 3 ·2H 2 O] n (where hfac = hexafluoroacetylacetonate) polymeric units on muscovite mica, which is observed by atomic force microscopy. The needle-like shape mimics the structure observed in the crystalline bulk material. The growth of this molecular organization is assisted by water adsorption on the freshly air-cleaved muscovite mica. This deposition technique allows for the observation of a significant amount of nanochains grown along three preferential directions 60° apart from another. The magnetic properties and the luminescence of the nanochains can be detected without the need of surface-dedicated instrumentation. The intermediate value of the observed luminescence lifetime of the deposits (132 µs) compared to that of the bulk (375 µs) and the CHCl 3 solution (13 µs) further reinforces the idea of water-induced growth., (Copyright © 2019, Evrard et al.; licensee Beilstein-Institut.)