Effect of aromatic substituents on the H-bonded assembly of diketopyrrolopyrroles at solid-liquid interfaces.

Hydrogen-bonded (H-bonded) self-assembly is a suitable approach for tailoring the solid-state packing and properties of organic semiconductors. Here we studied the H-bonded self-assembly of an important class of organic semiconductors, diketopyrrolopyrrole (DPP) derivatives, diselenophenylDPP (DSeDPP), dithiazolylDPP (DTzDPP), and dithienothiophenylDPP (DTTDPP), at solid-liquid interfaces using scanning tunneling microscopy (STM) and density functional theory (DFT). At the 1-octanoic acid/highly ordered pyrolytic graphite (HOPG) interface, DSeDPP and DTzDPP either co-assemble with the solvent H-bonding between lactam and carboxyl groups or form homoassemblies through H-bonding between the lactam groups.

Impact of the Core Chemistry of Self-Assembled Spherical Nucleic Acids on their In Vitro Fate.

Nucleic acid therapeutics (NATs), such as mRNA, small interfering RNA or antisense oligonucleotides are extremely efficient tools to modulate gene expression and tackle otherwise undruggable diseases. Spherical nucleic acids (SNAs) can efficiently deliver small NATs to cells while protecting their payload from nucleases, and have improved biodistribution and muted immune activation. Self-assembled SNAs have emerged as nanostructures made from a single DNA-polymer conjugate with similar favorable properties as well as small molecule encapsulation.

Two-Dimensional Supramolecular Polymerization of DNA Amphiphiles is Driven by Sequence-Dependent DNA-Chromophore Interactions.

Two-dimensional (2D) assemblies of water-soluble block copolymers have been limited by a dearth of systematic studies that relate polymer structure to pathway mechanism and supramolecular morphology. Here, we employ sequence-defined triblock DNA amphiphiles for the supramolecular polymerization of free-standing DNA nanosheets in water. Our systematic modulation of amphiphile sequence shows the alkyl chain core forming a cell membrane-like structure and the distal π-stacking chromophore block folding back to interact with the hydrophilic DNA block on the nanosheet surface.

Lyotropic Nematic Phases of Isotropic Nanoparticles via Semiflexible Polymer Ligands.

Lyotropic liquid crystalline (LC) nanomaterials are normally achieved through particle shape anisotropy. Herein, it is shown that lyotropic nematic rather than cubic phases are produced from spherical nanoparticles (NPs) with semi-flexible polymer ligands. ZrO nanocrystals (4 nm dia.

Ligand-flexible synthesis of strongly confined perovskite nanocrystals: a microwave synthetic approach.

Perovskite nanocrystals (PNCs) and their strongly confined versions have traditionally been synthesized hot injection methods. However, there is a pressing need for a new synthesis method that offers more flexible surface chemistry, improved optical properties, and greater sample stability. Here we explore and exploit the recently introduced microwave (MW) synthesis method, focusing on temperature and coating ligands, including a polymer ligand for which the hot injection method is unsuitable.