A photochromic metallacycle with highly anisotropic Dy-F magnetic units.

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.

Molecular Engineering onto RuII Bis(1,2-diphenylphosphinoethane) Synthon: Toward an Original Organometallic Gelator.

In this article, we report the successful molecular engineering of Ru bis-acetylides that led for the first time to a gelator and more specifically in aromatic solvents. By means of a nonlinear ligand and an extended aromatic platform, the bulky Ru bis-acetylides were able to self-assemble into lamellar structures as evidenced by scanning electron microscopy (SEM) in benzene, toluene, and o- and m-xylene, which in turn induced gelation of the solution with a critical gelation concentration of 30 mg/mL. Nuclear magnetic resonance (NMR), variable temperature (VT)-NMR, and Fourier transform infrared (FT-IR) spectroscopies evidenced that hydrogen bonds are mainly responsible for the self-organization. VT-NMR and small-angle X-ray scattering (SAXS) have also suggested that the pro-ligand and the complex stack in different ways.