Solid‐State and Solution Self‐assembly Properties of Mono‐ and Bis‐acetylide Ru^II Complexes Bearing Hydrogen‐Bonding Amide Functions

Abstract

In this work, we report our latest results regarding the selfassembly properties of two Ru-acetylides complexes and their corresponding free organic ligands, in solution and in the solid state. The four compounds show mesogenic properties, which we have rationalized thanks to extensive DSC, SAXS, POM, FTIR and molecular dynamic investigations. We clearly establish that hydrogen bonds stabilize the supramolecular structures, and that introducing the metal center and its coordination sphere induces large change in the liquid crystal properties. In addition, for the monoacetylide compound Ru 2 , solution-state studies helped us rationalize its supramolecular abilities. In particular, we demonstrate that Ru 2 follows an isodesmic growth supramolecular polymerization in aromatic solvent.

Kinetic Delay in Cooperative Supramolecular Polymerization by Redefining the Trade‐Off Relationship between H‐Bonds and Van der Waals/π–π Stacking Interactions

“…As these compounds can be easily functionalized, with acetylenic or with extended aromatic moieties (Scheme 1), some of us recently used such ligands to selfassemble bulky Ru II bis-acetylide complexes. [8] Herein, we further demonstrate for the first time that (i) the increase of π-π stacking interactions in TBAÀ PhA 12 compared to TBAÀ A 12 and (ii) the regulation of interchain VdW interactions in TBA derivatives functionalized with alkyl side chains of various length from new TBAÀ PhA 12 to new TBAÀ PhA 16 enables not only the control of the kinetic metastable states existence but also operates on the polymerization kinetic barrier to form 1D fibers. The characteristics of this state and of the polymerization process were determined experimentally, in particular with the observations of hysteresis loops, and modeled with the help of theoretical calculations.…”

“…Synthetic routes to obtain derivatives TBAÀ A 12 , TBAÀ PhA 12 were previously reported, [8,9] and TBAÀ PhA 8 and TBAÀ PhA 16 encompassing C 8 and C 16 alkyl chain lengths, respectively, (Scheme 1) were synthetized accordingly (SI).…”

Kinetic Delay in Cooperative Supramolecular Polymerization by Redefining the Trade‐Off Relationship between H‐Bonds and Van der Waals/π–π Stacking Interactions

“…In contrast, TBAÀ PhA 12 is known to form organogels in MCH, thanks to strong hydrogen bonding interactions. [8] This is undoubtedly confirmed by the FTIR spectrum at room temperature (C T = 10 mM) where the stretching vibration bands of NÀ H and C=O experience a dramatic red shift down to 3155 cm À 1 and 1636 cm À 1 , respectively (Figure S41).…”