Precise Sequence Control in Linear and Cyclic Copolymers of 2,5-Bis(2-thienyl)pyrrole and Aniline by DNA-Programmed Assembly

Design of Microstructure-Engineered Polymers for Energy and Environmental Conservation

With the ever-growing demand for sustainability, designing polymeric materials using readily accessible feedstocks provides potential solutions to address the challenges in energy and environmental conservation. Complementing the prevailing strategy of varying chemical composition, engineering microstructures of polymer chains by precisely controlling their chain length distribution, main chain regio-/stereoregularity, monomer or segment sequence, and architecture creates a powerful toolbox to rapidly access diversified material properties. In this Perspective, we lay out recent advances in utilizing appropriately designed polymers in a wide range of applications such as plastic recycling, water purification, and solar energy storage and conversion. With decoupled structural parameters, these studies have established various microstructure-function relationships. Given the progress outlined here, we envision that the microstructure-engineering strategy will accelerate the design and optimization of polymeric materials to meet sustainability criteria.

Macromolecular Information Transfer

Macromolecular information transfer can be defined as the process by which a coded monomer sequence is communicated from one macromolecule to another. In such a transfer process, the information sequence can be kept identical, transformed into a complementary sequence or even translated into a different molecular language. Such mechanisms are crucial in biology and take place in DNA→DNA replication, DNA→RNA transcription and RNA→protein translation. In fact, there would be no life on Earth without macromolecular information transfer. Mimicking such processes with synthetic macromolecules would also be of major scientific relevance because it would open up new avenues for technological applications (e.g. data storage and processing) but also for the creation of artificial life. In this important context, this minireview summarizes recent research about information transfer in synthetic oligomers and polymers. Medium- and long-term perspectives are also discussed.

Multifunctional behavior of molecules comprising stacked cytosine-AgI-cytosine base pairs; towards conducting and photoluminescence silver-DNA nanowires

DNA molecules containing a 1D silver array may be applied for nanotechnology applications, but first their conducting and photoluminescence behavior must be enhanced. Here we have synthesized and characterized three new helical compounds based on stacked silver-mediated cytosine base pairs [Ag(mC)2]X (mC = N1-methylcytosine; X = NO3 (1), BF4 (2) and ClO4 (3)), that contain uninterrupted polymeric AgI chains that run through the center of the helixes, comparable to related silver-DNA structures. The exposure of nanostructures of [Ag(mC)2]BF4 (2) to cold hydrogen plasma stimulates the reduction of the prearranged AgI polymeric chains to metallic silver along the material. This solvent-free reduction strategy leads to the compound [AgI(mC)2]X@Ag0 (2H) that contains uniformly well-distributed silver metallic nanostructures that are responsible for the new conducting and photoluminescence properties of the material. The presence of silver nanostructures alongside compound 2H has been evaluated by means of X-ray photoelectron spectroscopy (XPS), UV-vis spectroscopy, and X-ray powder diffraction (XRPD). The conducting and photoactive properties of 2H were studied by electrostatic force microscopy (EFM) and conducting-AFM (c-AFM), and photoluminescence microscopy (PL), respectively. The results demonstrate that the presence of well-organized metallic silver nanoentities on the material is responsible for the novel conductivity and photoactive properties of the material. This methodology can be employed for the generation of multifunctional silver-DNA related materials with tailored properties.

Template-directed synthesis of linear porphyrin oligomers: classical, Vernier and mutual Vernier

We demonstrate a variety of template-directed strategies for preparing linear monodisperse butadiyne-linked porphyrin oligomers by Glaser–Hay coupling, based on the coordination of pyridine-substituted nickel(ii) porphyrins to zinc(ii) porphyrins.

Three different types of template-directed syntheses of linear porphyrin oligomers are presented. In the classical approach the product has the same number of binding sites as the template, whereas in Vernier reactions the product has the lowest common multiple of the numbers of binding sites in the template and the building block. Mutual Vernier templating is like Vernier templating except that both strands of the Vernier complex undergo coupling simultaneously, so that it becomes impossible to say which is the ‘template’ and which is the ‘building block’. The template-directed synthesis of monodisperse linear oligomers is more difficult than that of cyclic oligomers, because the products of linear templating have reactive ends. All three types of templating are demonstrated here, and used to prepare a nickel(ii) porphyrin dodecamer with 4-pyridyl substituents on all twelve porphyrin units. The stabilities and cooperativities of the double-strand complexes involved in these reactions were investigated by UV-vis-NIR titration. The four-rung ladder duplex has a stability constant of about 2 × 10¹⁸ M^–1 in dichloromethane at 298 K.

Enzymatic oligomerization and polymerization of arylamines: state of the art and perspectives

The literature concerning the oxidative oligomerization and polymerization of various arylamines, e.g., aniline, substituted anilines, aminonaphthalene and its derivatives, catalyzed by oxidoreductases, such as laccases and peroxidases, in aqueous, organic, and mixed aqueous organic monophasic or biphasic media, is reviewed. An overview of template-free as well as template-assisted enzymatic syntheses of oligomers and polymers of arylamines is given. Special attention is paid to mechanistic aspects of these biocatalytic processes. Because of the nontoxicity of oxidoreductases and their high catalytic efficiency, as well as high selectivity of enzymatic oligomerizations/polymerizations under mild conditions-using mainly water as a solvent and often resulting in minimal byproduct formation-enzymatic oligomerizations and polymerizations of arylamines are environmentally friendly and significantly contribute to a "green" chemistry of conducting and redox-active oligomers and polymers. Current and potential future applications of enzymatic polymerization processes and enzymatically synthesized oligo/polyarylamines are discussed.

From nucleobase to DNA templates for precision supramolecular assemblies and synthetic polymers

In this minireview, we report on the recent advances of utilization of nucleobases and DNA as templates to achieve well-defined supramolecular polymers, synthetic polymers, and sequence-controlled polymers.

A composition-controlled cross-linking resin network through rapid visible-light photo-copolymerization

This work introduces a cross-linked resin network with controlled chemical composition, a clinically practical procedure to make it in situ, and appropriate analytical tools for chemical structure and kinetic studies.

Orientational nanoparticle assemblies and biosensors

Assemblies of nanoparticles (NPs) have regional correlated properties with new features compared to individual NPs or random aggregates. The orientational NP assembly contributes greatly to the collective interaction of individual NPs with geometrical dependence. Therefore, orientational NPs assembly techniques have emerged as promising tools for controlling inorganic NPs spatial structures with enhanced interesting properties. The research fields of orientational NP assembly have developed rapidly with characteristics related to the different methods used, including chemical, physical and biological techniques. The current and potential applications, important challenges remain to be investigated. An overview of recent developments in orientational NPs assemblies, the multiple strategies, biosensors and challenges will be discussed in this review.

Controlling monomer-sequence using supramolecular templates

This review discusses the template-directed preparation of sequence-defined polymers.

Engineering DNA self-assemblies as templates for functional nanostructures

CONSPECTUS: DNA is a well-known natural molecule that carries genetic information. In recent decades, DNA has been used beyond its genetic role as a building block for the construction of engineering materials. Many strategies, such as tile assembly, scaffolded origami and DNA bricks, have been developed to design and produce 1D, 2D, and 3D architectures with sophisticated morphologies. Moreover, the spatial addressability of DNA nanostructures and sequence-dependent recognition enable functional elements to be precisely positioned and allow for the control of chemical and biochemical processes. The spatial arrangement of heterogeneous components using DNA nanostructures as the templates will aid in the fabrication of functional materials that are difficult to produce using other methods and can address scientific and technical challenges in interdisciplinary research. For example, plasmonic nanoparticles can be assembled into well-defined configurations with high resolution limit while exhibiting desirable collective behaviors, such as near-field enhancement. Conducting metallic or polymer patterns can be synthesized site-specifically on DNA nanostructures to form various controllable geometries, which could be used for electronic nanodevices. Biomolecules can be arranged into organized networks to perform programmable biological functionalities, such as distance-dependent enzyme-cascade activities. DNA nanostructures can carry multiple cytoactive molecules and cell-targeting groups simultaneously to address medical issues such as targeted therapy and combined administration. In this Account, we describe recent advances in the functionalization of DNA nanostructures in different fashions based on our research efforts in nanophotonics, nanoelectronics, and nanomedicine. We show that DNA origami nanostructures can guide the assembly of achiral, spherical, metallic nanoparticles into nature-mimicking chiral geometries through hybridization between complementary DNA strands on the surface of nanoparticles and DNA scaffolds, to generate circular dichroism (CD) response in the visible light region. We also show that DNA nanostructures, on which a HRP-mimicking DNAzyme acts as the catalyst, can direct the site-selective growth of conductive polymer nanomaterials with template configuration-dependent doping behaviors. We demonstrate that DNA origami nanostructures can act as an anticancer-drug carrier, loading drug through intercalation, and can effectively circumvent the drug resistance of cultured cancer cells. Finally, we show a label-free strategy for probing the location and stability of DNA origami nanocarriers in cellular environments by docking turn-off fluorescence dyes in DNA double helices. These functionalizations require further improvement and expansion for realistic applications. We discuss the future opportunities and challenges of DNA based assemblies. We expect that DNA nanostructures as engineering materials will stimulate the development of multidisciplinary and interdisciplinary research.

Sequence-Controlled Polymers

Sequence-controlled polymers are macromolecules in which monomer units of different chemical nature are arranged in an ordered fashion. The most prominent examples are biological and have been studied and used primarily by molecular biologists and biochemists. However, recent progress in protein- and DNA-based nanotechnologies has shown the relevance of sequence-controlled polymers to nonbiological applications, including data storage, nanoelectronics, and catalysis. In addition, synthetic polymer chemistry has provided interesting routes for preparing nonnatural sequence-controlled polymers. Although these synthetic macromolecules do not yet compare in functional scope with their natural counterparts, they open up opportunities for controlling the structure, self-assembly, and macroscopic properties of polymer materials.