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Ultrafast 2D-IR spectroscopy is rapidly becoming a valuable tool for examining the relationship between structure and function of biomolecules. The unique combination of molecular-level structural information and ultrafast time resolution gives previously inaccessible insights relating to the rapid structural fluctuations, vibrational dynamics and solvent –solute interactions of proteins , all of which have important implications for the biological function of these species. In this tutorial review , the method and development of ultrafast 2D-IR spectroscopy is discussed, including an introduction to the two main experimental approaches, double resonance and photon echo 2D-IR , and the extension of the technique to non-equilibrium or transient 2D-IR measurements. The scope of the new information available through 2D-IR spectroscopy is then demonstrated by reference to the current state of the art of 2D-IR studies of molecules of biological interest.

Supramolecular self-assembly at surfaces provides a pathway for building chemically customized interfaces. Over the last three decades, research on the role of key parameters such as temperature, solute concentration, and molecular design has enabled a steady increase in the complexity of self-assembled molecular networks (SAMNs) that can thus be created. However, the structure and quality of SAMNs is often determined during the early stages of nucleation and growth. To study and influence self-assembly processes at this deterministic length scale, spatial confinement of molecular adsorbates to well-defined surface patterns with nanoscale lateral dimensions offers exciting possibilities. The aim of this tutorial review is to give an overview of the various ways in which confinement impacts SAMN formation, and how we can use that knowledge to direct assemblies towards desired structures. The possibility to exploit confinement for improved control over on-surface reactions is also contemplated.

COVID-19 has resulted in huge numbers of infections and deaths worldwide and brought the most severe disruptions to societies and economies since the Great Depression. Massive experimental and computational research effort to understand and characterize the disease and rapidly develop diagnostics, vaccines, and drugs has emerged in response to this devastating pandemic and more than 130?000 COVID-19-related research papers have been published in peer-reviewed journals or deposited in preprint servers. Much of the research effort has focused on the discovery of novel drug candidates or repurposing of existing drugs against COVID-19, and many such projects have been either exclusively computational or computer-aided experimental studies. Herein, we provide an expert overview of the key computational methods and their applications for the discovery of COVID-19 small-molecule therapeutics that have been reported in the research literature. We further outline that, after the first year the COVID-19 pandemic, it appears that drug repurposing has not produced rapid and global solutions. However, several known drugs have been used in the clinic to cure COVID-19 patients, and a few repurposed drugs continue to be considered in clinical trials, along with several novel clinical candidates. We posit that truly impactful computational tools must deliver actionable, experimentally testable hypotheses enabling the discovery of novel drugs and drug combinations, and that open science and rapid sharing of research results are critical to accelerate the development of novel, much needed therapeutics for COVID-19.

The emergence of new fungal pathogens makes the development of new antifungal drugs a medical imperative that in recent years motivates the talents of numerous investigators across the world. Understanding not only the structural families of these drugs but also their biological targets provides a rational means for evaluating the merits and selectivity of new agents for fungal pathogens and normal cells. An equally important aspect of modern antifungal drug development takes a balanced look at the problems of drug potency and drug resistance. The future development of new antifungal agents will rest with those who employ synthetic and semisynthetic methodology as well as natural product isolation to tackle these problems and with those who possess a clear understanding of fungal cell architecture and drug resistance mechanisms. This review endeavors to provide an introduction to a growing and increasingly important literature, including coverage of the new developments in medicinal chemistry since 2015, and also endeavors to spark the curiosity of investigators who might enter this fascinatingly complex fungal landscape.

The rising interest in fuel cell vehicle technology (FCV) has engendered a growing need and realization to develop rational chemical strategies to create highly efficient, durable, and cost-effective fuel cells. Specifically, technical limitations associated with the major constituent components of the basic proton exchange membrane fuel cell (PEMFC), namely the cathode catalyst and the proton exchange membrane (PEM), have proven to be particularly demanding to overcome. Therefore, research trends within the community in recent years have focused on (i) accelerating the sluggish kinetics of the catalyst at the cathode and (ii) minimizing overall Pt content, while simultaneously (a) maximizing activity and durability as well as (b) increasing membrane proton conductivity without causing any concomitant loss in either stability or as a result of damage due to flooding. In this light, as an example, high temperature PEMFCs offer a promising avenue to improve the overall efficiency and marketability of fuel cell technology. In this Critical Review, recent advances in optimizing both cathode materials and PEMs as well as the future and peculiar challenges associated with each of these systems will be discussed.

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While the concept of aromaticity is being more and more precisely delineated, the category of “aromatic compounds” is being more and more expanded. This is illustrated by an introductory highlight of the various types of “aromaticity” previously invoked, and by a focus on the recently proposed “aromatic character” of the “two-membered rings” of the acetylene and butatriene molecules. This serves as a general foundation for the definition of “ carbo -aromaticity”, the relevance of which is surveyed through recent results in the synthetic, physical, and theoretical chemistry of carbo -mers and in particular macrocyclic–polycyclic representatives constituting a natural family of “novel aromatic compounds”. With respect to their parent molecules, carbo -mers are constitutionally defined as “carbon-enriched”, and can also be functionally regarded as “π-electron-enriched”. This is exemplified by recent experimental and theoretical results on functional, aromatic, rigid, σ,π-macrocyclic carbo -benzene archetypes of various substitution patterns, with emphasis on the quadrupolar pattern. For the purpose of comparison, several types of non-aromatic references of carbo -benzenes are then considered, i.e . freely rotating σ,π-acyclic carbo-n -butadienes and flexible σ-cyclic, π-acyclic carbo -cyclohexadienes, and to “pro-aromatic” congeners, i.e . rigid σ,π-macrocyclic carbo -quinoids. It is shown that functional carbo -mers are entering the field of “molecular materials” for properties such as linear or nonlinear optical properties ( e.g. dichromism and two-photon absorption) and single molecule conductivity. Since total or partial carbo -mers of aromatic carbon-allotropes of infinite size such as graphene (graphynes and graphdiynes) and graphite (“graphitynes”) have long been addressed at the theoretical or conceptual level, recent predictive advances on the electrical, optical and mechanical properties of such carbo -materials are surveyed. Very preliminary experimental results on a carbo -benzenoid fragment are finally disclosed.

Inorganic and organic “solvent-in-salt” (SIS) systems have been known for decades but have attracted significant attention only recently. Molten salt hydrates/solvates have been successfully employed as non-flammable, benign electrolytes in rechargeable lithium-ion batteries leading to a revolution in battery development and design. SIS with organic components (for example, ionic liquids containing small amounts of water) demonstrate remarkable thermal stability and tunability, and present a class of admittedly safer electrolytes, in comparison with traditional organic solvents. Water molecules tend to form nano- and microstructures (droplets and channel networks) in ionic media impacting their heterogeneity. Such microscale domains can be employed as microreactors for chemical and enzymatic synthesis. In this review, we address known SIS systems and discuss their composition, structure, properties and dynamics. Special attention is paid to the current and potential applications of inorganic and organic SIS systems in energy research, chemistry and biochemistry. A separate section of this review is dedicated to experimental methods of SIS investigation, which is crucial for the development of this field.

A brief account of the recent developments in the chemistry of 1,2-benzoquinones is presented in this tutorial review . The title compounds exhibit commendable versatility in both Diels–Alder and dipolar cycloaddition reactions. They have also been employed as electrophilic reaction partners in nucleophile-triggered catalytic processes and related multicomponent reactions. These, along with other reactions described here, lead to the synthesis of densely functionalised carbocyclic and heterocyclic frameworks that are otherwise difficult to access.

Designing dendrimers that are monodisperse hyperbranched macromolecules and offer significant potential in numerous scientific fields, is becoming a major topical area in modern research. Among the challenges of the 21st century, synthetic methodologies that increase efficiency of conversion and a greener chemistry approach, are expected to lead the way in the quest to build novel nanomaterials. The recent entry of so-called “click” reactions that include Diels–Alder, Cu I -catalyzed Huisgen cycloaddition and thiol - ene coupling, have generated real stimulus not only in developing elegant materials of choice, but also in making the leap to industrial scale build-up of dendritic macromolecules . This tutorial review takes on the task of demonstrating the simplicity of these “click” reactions and the advantages they offer from a synthetic view point in developing mono- to multifunctional dendrimers . A brief introduction to “click” chemistry is followed by a chronological survey of developments in the field, and the impact these have had in designing novel dendritic macromolecules . The review is intended to introduce scientists to these highly efficient methodologies with demonstrated potential, and provide impetus for further growth of the area.