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.

Automated summary

In this article, the successful molecular engineering of Ru bis-acetylides to form a gelator in aromatic solvents is reported for the first time. The self-assembly of bulky Ru bis-acetylides into lamellar structures in benzene, toluene, and xylenes was confirmed by SEM, leading to gelation of the solution. The main driving force for the self-organization was found to be hydrogen bonding, with VT-NMR and SAXS suggesting different stacking modes for the pro-ligand and the complex.