This critical review will be of interest to the experts in porous solids (including catalysis), but also solid state chemists and physicists. It presents the state-of-the-art on hybrid porous solids, their advantages, their new routes of synthesis, the structural concepts useful for their ‘design’, aiming at reaching very large pores. Their dynamic properties and the possibility of predicting their structure are described. The large tunability of the pore size leads to unprecedented properties and applications. They concern adsorption of species, storage and delivery and the physical properties of the dense phases. (323 references)

Hybrid porous solids: past, present, future

We combined targeted chemistry and computational design to create a crystal structure for porous chromium terephthalate, MIL-101, with very large pore sizes and surface area. Its zeotype cubic structure has a giant cell volume (approximately 702,000 cubic angstroms), a hierarchy of extra-large pore sizes (approximately 30 to 34 angstroms), and a Langmuir surface area for N2 of approximately 5900 +/- 300 square meters per gram. Beside the usual properties of porous compounds, this solid has potential as a nanomold for monodisperse nanomaterials, as illustrated here by the incorporation of Keggin polyanions within the cages.

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A chromium terephthalate-based solid with unusually large pore volumes and surface area.

Approaches, Derivatives and Applications Vasilios Georgakilas,† Michal Otyepka,‡ Athanasios B. Bourlinos,‡ Vimlesh Chandra, Namdong Kim, K. Christian Kemp, Pavel Hobza,‡,§,⊥ Radek Zboril,*,‡ and Kwang S. Kim* †Institute of Materials Science, NCSR “Demokritos”, Ag. Paraskevi Attikis, 15310 Athens, Greece ‡Regional Centre of Advanced Technologies and Materials, Department of Physical Chemistry, Faculty of Science, Palacky University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i., Flemingovo naḿ. 2, 166 10 Prague 6, Czech Republic

Functionalization of Graphene: Covalent and Non-Covalent Approaches, Derivatives and Applications

/pdf/aryl-aryl-bond-formation-one-century-after-the-discovery-of-1jdyxlkwix.pdf

Aryl-aryl bond formation one century after the discovery of the Ullmann reaction.

The concept of isosterism between relatively simple chemical entities was originally contemplated by James Moir in 1909, a notion further refined by H. G. Grimm’s hydride displacement law and captured more effectively in the ideas advanced by Irving Langmuir based on experimental observations. Langmuir coined the term “isostere” and, 18 years in advance of its actual isolation and characterization, predicted that the physical properties of the then unknown ketene would resemble those of diazomethane. The emergence of bioisosteres as structurally distinct compounds recognized similarly by biological systems has its origins in a series of studies published byHans Erlenmeyer in the 1930s, who extended earlier work conducted by Karl Landsteiner. Erlenmeyer showed that antibodies were unable to discriminate between phenyl and thienyl rings or O, NH, and CH2 in the context of artificial antigens derived by reacting diazonium ions with proteins, a process that derivatized the ortho position of tyrosine, as summarized in Figure 1 The term “bioisostere” was introduced by Harris Friedman in 1950 who defined it as compounds eliciting a similar biological effect while recognizing that compounds may be isosteric but not necessarily bioisosteric. This notion anticipates that the application of bioisosterism will depend on context, relying much less on physicochemical properties as the underlying principle for biochemical mimicry. Bioisosteres are typically less than exact structural mimetics and are often more alike in biological rather than physical properties. Thus, an effective bioisostere for one biochemical application may not translate to another setting, necessitating the careful selection and tailoring of an isostere for a specific circumstance. Consequently, the design of bioisosteres frequently introduces structural changes that can be beneficial or deleterious depending on the context, with size, shape, electronic distribution, polarizability, dipole, polarity, lipophilicity, and pKa potentially playing key contributing roles in molecular recognition and mimicry. In the contemporary practice of medicinal chemistry, the development and application of bioisosteres have been adopted as a fundamental tactical approach useful to address a number of aspects associated with the design and development of drug candidates. The established utility of bioisosteres is broad in nature, extending to improving potency, enhancing selectivity, altering physical properties, reducing or redirecting metabolism, eliminating or modifying toxicophores, and acquiring novel intellectual property. In this Perspective, some contemporary themes exploring the role of isosteres in drug design are sampled, with an emphasis placed on tactical applications designed to solve the kinds of problems that impinge on compound optimization and the long-term success of drug candidates. Interesting concepts that may have been poorly effective in the context examined are captured, since the ideas may have merit in alternative circumstances. A comprehensive cataloging of bioisosteres is beyond the scope of what will be provided, although a synopsis of relevant isosteres of a particular functionality is summarized in a succinct fashion in several sections. Isosterism has also found productive application in the design and optimization of organocatalysts, and there are several examples in which functional mimicry established initially in a medicinal chemistry setting has been adopted by this community.

Synopsis of some recent tactical application of bioisosteres in drug design.

We report the synthesis of single-crystalline silver nanowires of atomic dimensions. The ultrathin silver wires with 0.4 nanometer width grow up to micrometer-scale length inside the pores of self-assembled calix[4]hydroquinone nanotubes by electro-/photochemical redox reaction in an ambient aqueous phase. The present subnanowires are very stable under ambient air and aqueous environments, unlike previously reported metal wires of ∼1 nanometer diameter, which existed only transiently in ultrahigh vacuum. The wires exist as coherently oriented three-dimensional arrays of ultrahigh density and thus could be used as model systems for investigating one-dimensional phenomena and as nanoconnectors for designing nanoelectronic devices.

https://science.sciencemag.org/content/sci/294/5541/348.full.pdf

Ultrathin Single-Crystalline Silver Nanowire Arrays Formed in an Ambient Solution Phase

Self-assembled arrays of organic nanotubes with infinitely long one-dimensional H-bond chains.

A series of novel beta-amyloid (A beta) aggregate-specific ligands, 2-(4'-dimethylaminophenyl)-6-iodoimidazo[1,2-a]pyridine, 16(IMPY), and its related derivatives were prepared. An in vitro binding study with preformed A beta aggregates showed that 16(IMPY) and its bromo derivative competed with binding of 2-(4'-dimethylaminophenyl)-6-iodobenzothiazole, [125I]7(TZDM), a known ligand for A beta aggregates, with high binding affinities (K(i) = 15 and 10 nM, respectively). In vitro autoradiography of brain sections of a transgenic mouse (Tg2576) with [125I]16(IMPY) displayed high selective binding to amyloid-like structures, comparable to that observed by staining with thioflavin-S visualized under fluorescence. In vivo biodistribution after an intravenous injection of [125I]16(IMPY) in normal mice showed a high initial brain uptake and fast washout, indicating a low background activity associated with this iodinated ligand. Taken together, the data suggests that [123I]16(IMPY) may be useful for imaging A beta aggregates in patients with Alzheimer's disease.

Structure−Activity Relationship of Imidazo[1,2-a]pyridines as Ligands for Detecting β-Amyloid Plaques in the Brain

Novel stilbenes as probes for amyloid plaques.

The present invention relates to substituted triazole compounds and compositions comprising substituted triazole compounds. The invention further relates to methods of inhibiting the activity of Hsp90 in a subject in need thereof and methods for preventing or treating hyperproliferative disorders, such as cancer, in a subject in need thereof comprising administering to the subject a substituted triazole compound of the invention, or a composition comprising such a compound.

Chi-Wan Lee

Papers

Ultrathin Single-Crystalline Silver Nanowire Arrays Formed in an Ambient Solution Phase

Self-assembled arrays of organic nanotubes with infinitely long one-dimensional H-bond chains.

Structure−Activity Relationship of Imidazo[1,2-a]pyridines as Ligands for Detecting β-Amyloid Plaques in the Brain

Novel stilbenes as probes for amyloid plaques.

Triazole compounds that modulate HSP90 activity