RNA oligomers at atomic resolution containing 1-methylpseudouridine, an essential building block of mRNA vaccines.

All widely used mRNA vaccines against COVID-19 contain in their sequence 1-methylpseudouridine (m1Ψ) instead of uridine. In this publication, we report two high resolution crystal structures (at up to 1.01 and 1.

Induced - rearrangements in {M(CO)} complexes (M = Re, Tc) by a PNP ligand.

The - rearrangements in [MX(CO)] (M = Re, Tc) induced by a pincer-type ligand (PNP) and a "halide scavenger" are reported. The reactions of -[Tc(CO)(OH)] or [TcO] in saline both yield -[Tc(PNP)(CO)], the first example of a -{Tc(CO)} type complex. In contrast, reactions with terpyridine (terpy) only gave the facial κ-terpy complexes with Re and Tc.

Electrocatalytic Ammonia Oxidation with a Tailored Molecular Catalyst Heterogenized via Surface Host-Guest Complexation.

Macrocyclic host molecules bound to electrode surfaces enable the complexation of catalytically active guests for molecular heterogeneous catalysis. We present a surface-anchored host-guest complex with the ability to electrochemically oxidize ammonia in both organic and aqueous solutions. With an adamantyl motif as the binding group on the backbone of the molecular catalyst [Ru(bpy-NMe)(tpada)(Cl)](PF) () (where bpy-NMe is 4,4'-bis(dimethylamino)-2,2'-bipyridyl and tpada is 4'-(adamantan-1-yl)-2,2':6',2″-terpyridine), high binding constants with β-cyclodextrin were observed in solution (in DMSO-:DO (7:3), = 492 ± 21 M).

Crystal structure of the nucleoside 2'-de-oxy-guanosine dimethyl sulfoxide disolvate.

The title com-pound, CHNO·2CHOS, which is of inter-est with respect to its biological activity, at 183 K has ortho-rhom-bic (222) crystal symmetry. The structure displays a network of inter-molecular N-H⋯N, N-H⋯O and O-H⋯O hydrogen bonds. 2'-De-oxy-guanosine mol-ecules are linked to each other and to the two dimethyl sulfoxide solvent mol-ecules by hydrogen bonding.

Saddles as rotational locks within shape-assisted self-assembled nanosheets.

Two-dimensional (2D) materials are a key target for many applications in the modern day. Self-assembly is one approach that can bring us closer to this goal, which usually relies upon strong, directional interactions instead of covalent bonds. Control over less directional forces is more challenging and usually does not result in as well-defined materials.

Comparing PVP and Polymeric Micellar Formulations of a PEGylated Photosensitizing Phthalocyanine by NMR and Optical Techniques.

Phthalocyanines are ideal candidates as photosensitizers for photodynamic therapy (PDT) of cancer due to their favorable chemical and photophysical properties. However, their tendency to form aggregates in water reduces PDT efficacy and poses challenges in obtaining efficient forms of phthalocyanines for therapeutic applications. In the current work, polyvinylpyrrolidone (PVP) and micellar formulations were compared for encapsulating and monomerizing a water-soluble zinc phthalocyanine bearing four non-peripheral triethylene glycol chains ().

Binding Small Molecules to a -Dicarbonyl Tc-PNP Complex via Metal-Ligand Cooperativity.

Metal-ligand cooperativity is a powerful tool for the activation of various bonds but has rarely, if ever, been studied with the radioactive transition metal Tc. In this work, we explore this bond activation pathway with the dearomatized PNP complex -[Tc(PNP*)(CO)] (), which was synthesized by deprotonation of -[Tc(PNP)(CO)Cl] with KOBu. Analogous to its rhenium congener, the dearomatized compound reacts with CO to form the carboxy complex -[Tc(PNP-COO)(CO)] and with H to form the mono-hydride complex -[Tc(PNP)(CO)H] ().

BODIPY-Based Photothermal Agents with Excellent Phototoxic Indices for Cancer Treatment.

Here, we report six novel, easily accessible BODIPY-based agents for cancer treatment. In contrast to established photodynamic therapy (PDT) agents, these BODIPY-based compounds show additional photothermal activity and their cytotoxicity is not dependent on the generation of reactive oxygen species (ROS). The agents show high photocytotoxicity upon irradiation with light and low dark toxicity in different cancer cell lines in 2D culture as well as in 3D multicellular tumor spheroids (MCTSs).

Azatriseptanes: Strained Framework Analogs of [7,7,7]Circulenes.

Invited for the cover of this issue is the group of Michel Rickhaus at the University of Zurich. The image depicts the "unearthing" of the highly contorted azatriseptane, a carbon framework consisting of three fused seven-membered rings surrounding a central nitrogen. Read the full text of the article at 10.

Azatriseptanes: Strained Framework Analogs of [7,7,7]Circulenes.

The synthesis and characterization of heptagon-embedded polycyclic aromatic compounds are essential for understanding the effect of negative curvature on carbon allotropes such as fullerenes and graphenes that have applications in functional organic materials. However, owing to the synthetic difficulties in functionalizing and embedding seven-membered rings, these strain-challenged structures are relatively unexplored. We report here the synthesis, characterization, and properties of a triarylamine core bridged with ethano chains at the 2,2'-positions.

Multitopic 3,2':6',3''-terpyridine ligands as 4-connecting nodes in two-dimensional 4,4-networks.

The tetratopic 1,4-bis(2-phenylethoxy)-2,5-bis(3,2':6',3''-terpyridin-4'-yl)benzene (1) and 1,4-bis(3-phenylpropoxy)-2,5-bis(3,2':6',3''-terpyridin-4'-yl)benzene (2) ligands have been prepared and fully characterised. Combination of ligand 1 or 2 and [M(hfacac)]·HO (M = Cu, = 1; M = Zn, = 2) under conditions of crystal growth by layering led to the formation of [Cu(hfacac)(1)] ·3.6(1,2-ClCH)·2CHCl, [Zn(hfacac)(1)] ·MeCH·1.

An Iridium-Stabilized Borenium Intermediate.

Exploration of new organometallic systems based on polyhedral boron clusters has the potential to solve challenging chemical problems such as the stabilization of reactive intermediates and transition-state-like species postulated for E-H (E = H, B, C, Si) bond activation reactions. We report on facile and clean B-H activation of a hydroborane by a new iridium boron cluster complex. The product of this reaction is an unprecedented and fully characterized transition metal-stabilized boron cation or borenium.

Low-Dose Near-Infrared Light-Activated Mitochondria-Targeting Photosensitizers for PDT Cancer Therapy.

Phthalocyanines (Pcs) are promising candidates for photodynamic therapy (PDT) due to their absorption in the phototherapeutic window. However, the highly aromatic Pc core leads to undesired aggregation and decreased reactive oxygen species (ROS) production. Therefore, short PEG chain functionalized AB type asymmetric Pc photosensitizers (PSs) were designed in order to decrease aggregation and increase the aqueous solubility.

Synthesis of Mesodiphenylhelianthrene from 1-Aminoanthraquinone and the Structural Elucidation of Its Endoperoxide Species after Irradiation.

A safe, five-step synthetic route to yield the reliable chemical actinometer, mesodiphenylhelianthrene (), is reported from a commercially available compound. Full characterization of the intermediates of the synthetic route and the final product are presented together with four crystal structures of intermediates and . The usage of the actinometer is described, and finally, the structure of the endoperoxide species (), which is formed after irradiation of , has been elucidated experimentally and theoretically.

A Cu -Salicylidene Glycinato Complex for the Selective Fluorometric Detection of Homocysteine over 20 Proteinogenic Amino Acids.

Homocysteine (Hcy) is a sulfur-containing α-amino acid that differs by one methylene (CH ) subunit from homologous cysteine (Cys). Elevated levels of Hcy are diagnostic markers of cardiovascular disease and other medical conditions. We present a new Cu -salicylidene glycinato complex 1 for the selective fluorometric detection of Hcy in water.

Natural-Product-Directed Catalytic Stereoselective Synthesis of Functionalized Fused Borane Cluster-Oxazoles for the Discovery of Bactericidal Agents.

The identification of an alternative chemical space in order to address the global challenge posed by emerging antimicrobial resistance is very much needed for the discovery of novel antimicrobial lead compounds. Boron clusters are currently being explored in drug discovery due to their unique steric and electronic properties. However, the challenges associated with the synthesis and derivatization techniques of these compounds have limited their utility in the rapid construction of a library of molecules for screening against various biological targets as an alternative molecular platform.

Thiolation and Carboxylation of Glutathione Synergistically Enhance Its Lead-Detoxification Capabilities.

The natural tripeptide glutathione (GSH) is a ubiquitous compound harboring various biological tasks, among them interacting with essential and toxic metal ions. Yet, although weakly binding the poisonous metal lead (Pb), GSH poorly detoxifies it. β-Mercaptoaspartic acid is a new-to-nature novel amino acid that was found to enhance the Pb-detoxification capability of a synthetic cyclic tetrapeptide.

Relativity as a Synthesis Design Principle: A Comparative Study of [3 + 2] Cycloaddition of Technetium(VII) and Rhenium(VII) Trioxo Complexes with Olefins.

The difference in [3 + 2] cycloaddition reactivity between -[MO(tacn)] (M = Re, Tc; tacn = 1,4,7-triazacyclononane) complexes has been reexamined with a selection of unsaturated substrates including sodium 4-vinylbenzenesulfonate, norbornene, 2-butyne, and 2-methyl-3-butyn-2-ol (2MByOH). None of the substrates was found to react with the Re cation in water at room temperature, whereas the Tc reagent cleanly yielded the [3 + 2] cycloadducts. Interestingly, a bis-adduct was obtained as the sole product for 2MByOH, reflecting the high reactivity of a TcO-enediolato monoadduct.

Potent PBS/Polysorbate-Soluble Transplatin-Derived Porphyrin-Based Photosensitizers for Photodynamic Therapy.

In this study, we addressed an important drawback of our previously reported tetraplatinated (metallo)porphyrin-based photosensitizers (PSs) for photodynamic therapy (PDT), namely, the poor solubility in aqueous media. We aimed to create tetraplatinated porphyrin-based PSs that are soluble in aqueous media modified with polysorbate (Tween) and do not need to be pre-dissolved in organic solvents. A structural optimization of the previously reported PSs resulted in the synthesis of an extremely potent novel porphyrin-based PS.

New Crystalline Salts of Nicotinamide Riboside as Food Additives.

NR is a highly effective vitamin B type supplement due to its unique ability to replenish NAD levels. While NR chloride is already on the market as a nutritional supplement, its synthesis is challenging, expensive, and low yielding, making it cumbersome for large-scale industrial production. Here we report the novel crystalline NR salts, d/l/dl-hydrogen tartrate and d/l/dl-hydrogen malate.

Photostable Platinated Bacteriochlorins as Potent Photodynamic Agents.

Photodynamic therapy (PDT) is used to treat various cancerous diseases. Recently, we have demonstrated that platinated pyridyl-substituted porphyrins are potent agents for PDT with very high phototoxicity (IC down to 17 nM) and excellent phototoxic indices of higher than 5800 (p.i.

Enantioselective Bifunctional Ammonium Salt-Catalyzed Syntheses of 3-CFS-, 3-RS-, and 3-F-Substituted Isoindolinones.

We herein report the ammonium salt-catalyzed synthesis of chiral 3,3-disubstituted isoindolinones bearing a heteroatom functionality in the 3-position. A broad variety of differently substituted CFS- and RS-derivatives were obtained with often high enantioselectivities when using Maruoka's bifunctional chiral ammonium salt catalyst. In addition, a first proof-of-concept for the racemic synthesis of the analogous F-containing products was obtained as well, giving access to one of the rare examples of a fairly stable α-F-α-amino acid derivative.

Exploring the Coordination Chemistry of N with Technetium PNP Pincer-Type Complexes.

Dinitrogen (N) complexes of technetium (Tc) are rare, and only two examples have been reported. To complement this important class of complexes also for Tc, two different pincer-type complexes of Tc were studied to assess their abilities for coordinating dinitrogen. The reactions of the Tc complex [TcCl(PPh)(NCCH)] with the pincer ligands PNP and PNP respectively gave [Tc(PNP)Cl] and [Tc(PNP)Cl], the first structurally characterized Tc complexes with -coordinated pincer ligands.

Cobalt Complexes of Polypyridyl Ligands for the Photocatalytic Hydrogen Evolution Reaction.

The reductive part of artificial photosynthesis, the reduction of protons into H₂, is a two electron two proton process. It corresponds basically to the reactions occurring in natural photosystem I. We show in this review a selection of involved processes and components which are mandatory for making this light-driven reaction possible at all.