Pathway and Length Control of Supramolecular Polymers in Aqueous Media via a Hydrogen Bonding Lock

Abstract

Programming the organization of π‐conjugated systems into nanostructures of defined dimensions is a requirement for the preparation of functional materials. Herein, we have achieved high‐precision control over the self‐assembly pathways and fiber length of an amphiphilic BODIPY dye in aqueous media by exploiting a programmable hydrogen bonding lock. The presence of a (2‐hydroxyethyl)amide group in the target BODIPY enables different types of intra‐ vs. intermolecular hydrogen bonding, leading to a competition between kinetically controlled discoidal H‐type aggregates and thermodynamically controlled 1D J‐type fibers in water. The high stability of the kinetic state, which is dominated by the hydrophobic effect, is reflected in the slow transformation to the thermodynamic product (several weeks at room temperature). However, this lag time can be suppressed by the addition of seeds from the thermodynamic species, enabling us to obtain supramolecular polymers of tuneable length in water for multiple cycles.

Living supramolecular polymerization of fluorinated cyclohexanes

“…Fourier-transform infrared spectral measurement (FT-IR) performed with 1.2 mM solution of M 3 C 6 H 12 /CHCl 3 (84:16 v/v) revealed no presence of stretching frequency corresponding to hydrogen-bonded amide hydrogens but small shifts of amide I band which could be attributed to the formation of CH•••π interactions between all-cis C 6 H 6 F 5 and aromatic ring (Supplementary Figs. 23,24). Combined HOESY and FTIR results confirm that folding is indeed present but likely not limited to a single structure and conventional C=O•••H-N intramolecular hydrogen bond.…”

“…Many recent examples of LSP are based on a similar use of offpathway aggregates 14 , which can be self-assembled from diverse building blocks such as rylene dyes [15][16][17][18][19][20][21] , (aza)-BODIPY dyes 22,23 , N-heteroangulenes 24 and amphiphilic Pt II complexes 25 . Further examples make use of the counter-anion modulated aggregation of Pt II and Pd II pincer-type complexes 26 , the coupling of SP with a chemical fuel or light [27][28][29][30] , the trapping of an active monomer using "dummy" monomers incapable of 1D supramolecular polymerization 31 and the amplification of macrocycles from dynamic combinatorial libraries 32 .…”

Nature‐Inspired Functional Chromophores from Biomimetic o‐Quinone Chemistry

“…[7][8][9] Interestingly, in an ever-increasing number of cases an important role in the overall optical and electronic performance of functional dyes is attributed to aggregation, which may be governed by hydrogen bonding or stacking interactions. [10,11] Accordingly, the 3D nanomolecular morphology and the supramolecular architecture of the chromophoric aggregates may represent most critical "extrinsic" factors that, combined with the "intrinsic" π-electron properties, regulate the overall behavior of the functional system.…”

Tweaking a BODIPY Spherical Self‐Assembly to 2D Supramolecular Polymers Facilitates Excited‐State Cascade Energy Transfer

“…Among different chromophores,4 ,4-difluoro-4-bora-3a-4a-diaza-s-indacene (BODIPY) is an excellent choice for creating supramolecular optoelectronic materials due to their photostability,h igh molar absorptivity and sensitive fluorescence features. [17][18][19][20] Here,w ed emonstrate how distinct energy landscapes can be obtained by creating different morphological features that facilitate reversible modulation of emission behavior. This is possible by tweaking the selfassembly of meso p-extended BODIPY dyes 1-3 ( Figure 1a) with solvents as established in this work.…”