Interplay between H‐Bonding and Preorganization in the Evolution of Self‐Assembled Systems

Philips, Divya Susan; Kartha, Kalathil K.; Politi, Antiope T.; Krüger, Timo; Albuquerque, Rodrigo Q.; Fernández, Gustavo

doi:10.1002/anie.201813955

Cited by 48 publications

(44 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These spectral changes are typical of a face‐to‐face H‐type aggregation process, in which the stacked OPE units adopt a slightly twisted conformation, possibly to alleviate the steric effects caused by the bulky side chains. This behavior has been also reported for a number of π‐conjugated systems, including perylene bisimides, BODIPY dyes, and also OPEs . The formation of H‐type aggregates at pH 11 is further supported by the featureless and comparatively weaker emission band (quenching of ca.…”

Section: Methodssupporting

confidence: 66%

pH‐Responsive Side Chains as a Tool to Control Aqueous Self‐Assembly Mechanisms

Kartha

Wendler

Rudolph

et al. 2019

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

pH-Tunable nanoscale morphologya nd self-assembly mechanism of as eries of oligo(p-phenyleneethynylene)( OPE)-based bolaamphiphiles featuring poly(ethylene imine) (PEI) side chains of differentl ength and degree of hydrolysis are described. Protonation and deprotonation of the PEI chainsb yc hanging the pH alters the hydrophilic/hydrophobic balance of the systems and, in turn, the strength of intermoleculari nteractions between the hydrophobic OPE moieties. Low pH values (3) lead to weak interaction betweent he OPEs and resulti ns pherical nanoparticles, in whicha ggregation follows an isodesmic mechanism. In contrast, higherp Hv alues (11) induce deprotonation of the polymer chains and lead to as tronger, cooperativea ggregation into anisotropic nanostructures. Our resultsd emonstrate that pH-responsive chains can be exploited as at ool to tune self-assemblymechanisms, which opens exciting possibilities to develop new stimuliresponsive materials. Supramolecular polymerization enables the creation of functional materials with multiple potentiala pplicationsi nvarious fields including optoelectronics or life sciences. [1] This bottomup approachr elies on the use of dynamic and reversible noncovalenti nteractions, which provides the system with outstanding properties, such as responsivenesst oe xternals timuli or self-healing. [2] Meanwhile, detailed mechanistic investigations of supramolecular polymerization processes have been reported for different types of buildingb locks. [3] The majority of these systemsc an be described by two main polymerization mechanisms-isodesmic and cooperative. [4] The determinants of ag iven mechanistic pathway are the type and number of non-covalent interactions. [5] Although supramolecularp olymers only exhibiting p-p stacking are usually described by the isodesmic mechanism, the combination of p-stacking and Hbondingg enerally guarantees ac ooperative mechanism,p rovided that no strong repulsive effectsa re present. [6] Regulation of these mechanismsi sahot topic in current research, which is possible by alteringthe molecular design or by adjusting the physicalp arameters (temperature, solvent, and/orc oncentration) to preparet he aggregate solution. However,p redicting the type of self-assembly mechanismb ym olecular design is still challenging, and the development of advanced self-assembled systemsw ith tailoredm echanismsi saprerequisite to generalize this trend.Previously,o ur groups reported that the self-assembly mechanism (isodesmic vs.c ooperative) of polymer-functionalized OPE-based bolaamphiphiles in aqueous mediac an be directly correlated with the polymer chain length. [7] This molecular engineering methode nables the fine tuning of the hydrophilic/ hydrophobic balance,w hich in turn determines the aggregate morphology (organized 2D lamellae vs. disorganizedn anoparticles). These findingsp rompted us to investigate whether the hydrophilic/hydrophobicr atio and the resulting aggregation behavior could also be controlled by pH changes. In that regard, pH-responsive pol...

show abstract

Section: Methodssupporting

confidence: 66%

pH‐Responsive Side Chains as a Tool to Control Aqueous Self‐Assembly Mechanisms

Kartha

Wendler

Rudolph

et al. 2019

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

show abstract

“…Interestingly, these signals shield and broaden at temperatures considerably higher than the T e (ca. 308 K), which may be related to a pre‐nucleation event into disordered short oligomers prior to the subsequent elongation …”

Section: Methodsmentioning

confidence: 99%

Mechanistic Insights into Statistical Co‐Assembly of Metal Complexes

Coelho

Matern

Albuquerque

et al. 2019

Chemistry A European J

Self Cite

View full text Add to dashboard Cite

Statistical copolymerization plays a key role in many biological and technological processes; however, mechanistic understanding of the formation of analogous supramolecular counterparts remains limited. Herein, we report detailed insights into the supramolecular co‐assembly of two π‐conjugated PdII and PtII complexes, which in isolation self‐assemble into flexible fibers and nanodisks, respectively. An efficient single‐step co‐assembly into only one type of nanostructure (fibers or nanodisks) takes place if any of the components is in excess. In contrast, equimolar mixtures lead to PdII‐rich fiber‐like co‐assemblies by a statistical co‐nucleation event along with a residual amount of self‐sorted nanodisks in a stepwise manner.

show abstract

“…This preorganization strongly favours the formation of more activated pre-nuclei with a higher tendency to form ordered molecular stacks during the subsequent elongation step. [29]…”

Section: π-Extended Tricarboxamidesmentioning

confidence: 99%

C₃‐Symmetrical π‐Scaffolds: Useful Building Blocks to Construct Helical Supramolecular Polymers

Dorca

Matern

Fernández

et al. 2019

Israel Journal of Chemistry

Self Cite

View full text Add to dashboard Cite

In this review, we highlight some relevant examples of C3‐symmetrical molecules that have been reported to form supramolecular polymers and helical aggregates. In particular, the number and type of non‐covalent forces are key to bias the supramolecular polymerization leading from a simple isodesmic or cooperative mechanism to a more complex self‐assembly process, i. e. pathway complexity. Furthermore, the attachment of stereogenic centres at the peripheral side chains of the C3‐systems provokes efficient transfer and amplification of chirality phenomena when directional and specific non‐covalent interactions operate. Interestingly, the incorporation of hydrophilic side chains induces the formation of organized aggregates in aqueous media with potential biomedical applications. Overall, the examples shown in this review on C3‐symmetrical scaffolds illustrate the relevance of this molecular shape in the development of functional supramolecular structures.

show abstract

Interplay between H‐Bonding and Preorganization in the Evolution of Self‐Assembled Systems

Cited by 48 publications

References 67 publications

pH‐Responsive Side Chains as a Tool to Control Aqueous Self‐Assembly Mechanisms

pH‐Responsive Side Chains as a Tool to Control Aqueous Self‐Assembly Mechanisms

Mechanistic Insights into Statistical Co‐Assembly of Metal Complexes

C₃‐Symmetrical π‐Scaffolds: Useful Building Blocks to Construct Helical Supramolecular Polymers

Contact Info

Product

Resources

About

Interplay between H‐Bonding and Preorganization in the Evolution of Self‐Assembled Systems

Cited by 48 publications

References 67 publications

pH‐Responsive Side Chains as a Tool to Control Aqueous Self‐Assembly Mechanisms

pH‐Responsive Side Chains as a Tool to Control Aqueous Self‐Assembly Mechanisms

Mechanistic Insights into Statistical Co‐Assembly of Metal Complexes

C3‐Symmetrical π‐Scaffolds: Useful Building Blocks to Construct Helical Supramolecular Polymers

Contact Info

Product

Resources

About

C₃‐Symmetrical π‐Scaffolds: Useful Building Blocks to Construct Helical Supramolecular Polymers