Thermosolutal Self-Organization of Supramolecular Polymers into Nanocraters

Abstract

The ability of two complementary molecular modules bearing H-bonding uracilic and 2,6-(diacetylamino)pyridyl moieties to self-assemble and self-organize into submicrometer morphologies has been investigated by means of spectroscopic, thermogravimetric, and microscopic methods. Using uracilic (3)N-BOC-protected modules, it has been possible to thermally trigger the self-assembly/self-organization process of the two molecular modules, inducing the formation of objects on a mica surface that exhibit crater-like morphology and a very homogeneous size distribution. Confirmation of the presence of the hydrogen-bonding-driven self-assembly/self-organization process in solution was obtained by variable-temperature (VT) steady-state UV-vis absorption and emission measurements. The variation of the geometric and spatial features of the morphologies was monitored at different T by means of atomic force microscopy (AFM) and was interpreted by a nonequilibrium diffusion model for two chemical species in solution. The formation of nanostructures turned out to be affected by the solid substrate (molecular interactions at a solid-liquid interface), by the matter-momentum transport in solution (solute diffusivity D(0) and solvent kinematic viscosity ν), and the thermally dependent cleavage reaction of the BOC functions (T-dependent differential weight loss, θ = θ(Τ)) in a T interval extrapolated to ∼60 K. A scaling function, f = f (νD(0), ν/D(0), θ), relying on the onset condition of a concentration-driven thermosolutal instability has been established to simulate the T-dependent behavior of the structural dimension (i.e., height and radius) of the self-organized nanostructures as ⟨h⟩ ≈ f (T) and ⟨r⟩ ≈ 1/f (T).

Nanosheets of an Organic Molecular Assembly from Aqueous Medium Exhibit High Solid‐State Emission and Anisotropic Charge‐Carrier Mobility

“…[34,35] We have adopted Suzuki coupling and click chemistry to synthesize the PDPP-Amphi. [7][8][9][10][11][12][13][14][15] In most of the cases, spontaneous self-assembly of organic molecules leads to 1D structures, but preparation of the corresponding 2D sheets of a few layer thickness is a challenge. [36] The thermal properties of PDPP-Amphi were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) ( Figure S1a ,b, Supporting Information).…”

“…[4][5][6] During the past two decades, supramolecular chemistry has been exploited for the creation of a variety of 0D, 1D, 2D, and 3D nanomaterials. [7][8][9][10][11][12][13][14][15] In most of the cases, spontaneous self-assembly of organic molecules leads to 1D structures, but preparation of the corresponding 2D sheets of a few layer thickness is a challenge. [16][17][18][19] 2D sheets of fluorescent molecules are required for display and sensing applications, however, organic 2D nanosheets having high fluorescence quantum yield is difficult to achieve due to the fluorescence self-quenching.…”

Hierarchised luminescent organic architectures: design, synthesis, self-assembly, self-organisation and functions

“…In an another recent report, 170 we have also demonstrated that it is possible to thermally trigger 171 the self-assembly/ self-organisation processes to induce the formation of objects on a mica surface that exhibit crater-like morphologies and a very homogeneous size distribution (Fig. 22).…”

Toward Fractioning of Isomers through Binding-Induced Acceleration of Azobenzene Switching

“…In this way, any changes occurring at one of the two moieties are then reflected on the other. Capitalizing on our previous achievements on the H-bonded uracil·2,6-diamidopyridine complex, − we therefore designed and synthesized a photoswitchable uracil–azobenzene derivative presenting direct anchoring of the phenyldiazenyl group to the nucleobase at either the 5- or 6-position ( 5AUP and 6AUP , respectively, Figure ).…”