Influence of Metal, Ligand and Solvent on Supramolecular Polymerizations with Transition‐Metal Compounds: A Theoretical Study

Abstract

Abstract:The nature of intermolecular interactions governing supramolecular polymerizations is very important to control their cooperativity. In order to address this problem, supramolecular columns made of Pt(II) and Pd(II) complexes of oligo(phenylene ethynylene)-based pyridine (OPE) and tetrazolyl-pyridine ligands (TEP) were investigated through the dispersion-corrected PM6 method. Aromatic, CH-π, M-Cl and metallophilic interactions helped stabilize the supramolecules studied, and their geometries and associated cooperativities were in excellent agreement with experimental data. The OPE ligand and/or the presence of Pt(II) have led to stronger metallophilic interactions and also to cooperative supramolecular polymerizations, which clearly suggests that metallophilic interactions are a key factor to control cooperativity. The results indicate that sequential monomer addition is in general less spontaneous than the combination of two larger pre-formed stacks. The present theoretical investigations contribute to the further understanding of the relation between the thermodynamics of supramolecular polymerizations and the nature of different synthons.

Self‐Assembly of 9,10‐Bis(phenylethynyl) Anthracene (BPEA) Derivatives: Influence of π–π and Hydrogen‐Bonding Interactions on Aggregate Morphology and Self‐Assembly Mechanism

“…The dispersion‐corrected semiempirical PM6 model in vacuum was used to obtain additional insight into the aggregation patterns of 1 and 2 , as it has been used successfully to describe other similar supramolecular systems . The optimized structures of octamers of 1 and 2 having short methoxy groups as side chains are shown in Figure , in which hydrogens were omitted for clarity.…”

“…The dispersion-corrected semiempirical PM6m odel in vacuum [26] was used to obtain additional insight into the aggregation patternso f1 and 2,a si th as been used successfully to describe other similars upramolecular systems. [27,28] The optimized structures of octamers of 1 and 2 having short methoxy groups as side chains are shown in Figure 6, in which hydrogens were omitted for clarity.T he angle q betweent he line joining the centero fm ass of adjacent anthracenesa nd the long axis of one of them was about 758;t hat is, larger than the threshold value of 54.78 necessary to be consideredH -aggregates, [29] which is in agreement with the photophysical data showni nF igure 2. The respective DH f values for the monomer addition were in all cases exothermic andr oughly constant for 1,o rs lightly more negative upon growth in thec ase of 2 ( Table S3 in the Supporting Information), which reinforces the fact that the former might grow in an isodesmic fashion and the latter cooperatively.T he monomer units of 1 inside the optimizeds tack ( Figure 6) are considerably more distorted at the edges,w hich is related to the lack of the long dodecyl side chains, as already discussed in our previousw ork.…”

Solute–Solvent Interactions in Modern Physical Organic Chemistry: Supramolecular Polymers as a Muse

“…Despite the analogies between destabilization of supramolecular polymers by good solvents and of proteins by urea and guanidinium, the molecular interactions leading to dissolution of the polymers by the good solvent are only poorly understood. Several theoretical reports suggest that good solvents stabilize the monomers, rather than destabilize the polymers. , …”

Recent progress and future challenges in the supramolecular polymerization of metal-containing monomers

“…A plethora of studies investigating different molecular design aspects, such as the nature of the metal ion, 54,55 coordination geometry, 56,57 the influence of ancillary ligands, 58 different linking units, 59,60 chain length at the ligand backbone 61 or the influence of counterions 62 for charged complexes have brought about important insights on aspects of metallosupramolecular polymerization. From these diverse studies, a few generally applicable rules, which draw parallels to "conventional" SPs could be confirmed.…”