186,434 research outputs found
Halogen-bonded photoresponsive materials
No full textThe aim of the present review is to illustrate to the reader the state of the art on the construction of supramolecular azobenzene-containing materials formed by halogen bonding. These materials include several examples of polymeric, liquid crystalline or crystalline species whose performances are either superior to the corresponding performances of their hydrogen-bonded analogues or simply distinctive of the halogen-bonded specie
Applications of fluorous compounds in materials chemistry: 12.3 self-assembly of hybrid fluorous materials
No full textCelebrating 150 years from Mendeleev: The Periodic Table of Chemical Interactions
No full textYear 2019 marked the sesquicentennial anniversary of Mendeleev’s paper and many events were organized to celebrate this milestone in science. We considered that linking to Periodic Table of Chemical Elements the repeating trends observed in the chemical interactions formed by various elements was a particularly timely and remarkable tribute to that milestone and his inventor. A collection of reviews acknowledging and framing this link was the most convenient tool to pursue our objective and we are grateful to Prof. P. A. Gale for accepting to publish in Coordination Chemistry Reviews the Article Collection entitled “Celebrating 150 Years from Mendeleev: The Periodic Table of Chemical Interactions”
Haloperfluorocarbons: Versatile Tectons in Halogen Bonding Based Crystal Engineering
No full textChapter 30info:eu-repo/semantics/publishe
Halogen Bond: A Long Overlooked Interaction
No full textBecause of their high electronegativity, halogen atoms are typically considered, in most of their derivatives, as sites of high electron density and it is commonly accepted that they can form attractive interactions by functioning as the electron donor site (nucleophilic site). This is the case when they work as hydrogen bond acceptor sites. However, the electron density in covalently bound halogens is anisotropically distributed. There is a region of higher electron density, accounting for the ability of halogens to function as electron donor sites in attractive interactions, and a region of lower electron density where the electrostatic potential is frequently positive (mainly in the heavier halogens). This latter region is responsible for the ability of halogen atoms to function as the electron-acceptor site (electrophilic site) in attractive interactions formed with a variety of lone pair-possessing atoms, anions, and π-systems. This ability is quite general and is shown by a wide diversity of halogenated compounds (e.g., organohalogen derivatives and dihalogens). According to the definition proposed by the International Union of Pure and Applied Chemistry, any attractive interactions wherein the halogen atom is the electrophile is named halogen bond (XB). In this chapter, it is discussed how the practice and the concept of XB developed and a brief history of the interaction is presented. Papers (either from the primary or secondary literature) which have reported major experimental findings in the field or which have given important theoretical contributions for the development of the concept are recollected in order to trace how a unifying and comprehensive categorization emerged encompassing all interactions wherein halogen atoms function as the electrophilic site
Inside Cover: Natural Abundance 15 N and 13 C Solid-State NMR Chemical Shifts: High Sensitivity Probes of the Halogen Bond Geometry (Chem. Eur. J. 47/2016)
No full textNatural abundance 15N solid-state NMR spectroscopy provides an effective method for the direct evaluation of halogen bond (XB) geometry. The change in the 15N SSNMR chemical shifts in halogen-bonded co-crystals of different dipyridyl derivatives with halobenzenes and diiodoalkanes as XB-donors is generally greater than 13C chemical shifts and it is shown to experimentally correlate with the normalized distance parameter of the XB. The same overall trend is confirmed by DFT calculations of the chemical shifts. More information can be found in the Full Paper by R. Gobetto, P. Metrangolo et al
Photoluminescent nanocluster-based probes for bioimaging applications
No full textIn the continuous search for versatile and better performing probes for optical bioimaging and biosensing applications, many research efforts have focused on the design and optimization of photoluminescent metal nanoclusters. They consist of a metal core composed by a small number of atoms (diameter < 2–3 nm), usually coated by a shell of stabilizing ligands of different nature, and are characterized by molecule-like quantization of electronic states, resulting in discrete and tunable optical transitions in the UV–Vis and NIR spectral regions. Recent advances in their size-selective synthesis and tailored surface functionalization have allowed the effective combination of nanoclusters and biologically relevant molecules into hybrid platforms, that hold a large potential for bioimaging purposes, as well as for the detection and tracking of specific markers of biological processes or diseases. Here, we will present an overview of the latest combined imaging or sensing nanocluster-based systems reported in the literature, classified according to the different families of coating ligands (namely, peptides, proteins, nucleic acids, and biocompatible polymers), highlighting for each of them the possible applications in the biomedical field. Graphical abstract: [Figure not available: see fulltext.
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