RADIATION-INDUCED CHANGES IN THE STRUCTURE AND FERROELECTRIC PROPERTIES OF Pb5Ge3O11 SINGLE CRYSTALS

Journal of Structural Chemistry - Perfect stoichiometric Pb5Ge3O11 single crystals are irradiated with 60Co γ-rays (1·106 Rad) and high-energy electrons (0.13 e/cm2, 0.89 e/cm2,...     

The Stability of Mononuclear and Binuclear Complexes of Silver(I) with Thiosemicarbazide in an Aqueous Solution

Moscow University Chemistry Bulletin - The complexation process of silver(I) ions with thiosemicarbazide (Tsc) in a wide range of concentrations of silver(I) and thiosemicarbazide at T =...     

Quantum Mechanical Study of the Covalent Bonding of Troxacitabine with Functionalized Carbon Nanotubes

Moscow University Chemistry Bulletin - The present study aimed to investigate use of density functional theory, noncovalent interactions and possible mechanisms of covalent functionalization of...     

Photometric Determination of Copper(II) by the Catalytic Action on the Reaction of Iron(III) Reduction with Thiosulfate Ion

Moscow University Chemistry Bulletin - A procedure is proposed for the kinetic determination of copper(II) by its catalytic effect on the reduction of iron(III) with thiosulfate ion, followed by...     

Photocatalytic Air Decontamination from Volatile Organic Pollutants Using Graphite-Like Carbon Nitride: a Review

Theoretical and Experimental Chemistry - The latest research on photocatalytic systems based on graphite-like carbon nitride (g-C3N4) for decontamination of air pollutants, in particular, volatile...     

Coordination Complexes to Combat Bacterial Infections: Recent Developments,Current Directions and Future Opportunities

Drug discovery aimed at the efficient eradication of life-threatening bacterial infections, especially in light of the emergence of multi-drug resistance of pathogenic bacteria, has remained a challenge for medicinal chemists over the past several decades. As nutrient acquisition and metabolism at the host-pathogen interface become better elucidated, new drug targets continue to emerge. Metal homeostasis is among these processes, and thus provides opportunities for medicinal inorganic chemists to alter or disrupt these processes selectively to impart bacteriostatic or bacteriotoxic effects. In this minireview, we showcase some of the recent work from the field of metal-based antibacterial agents and highlight divergent strategies and mechanisms of action.     

Experimental and Computational Study on the Anti-Markovnikov Hydrofunctionalization of Olefins Using Glycine-Extended AQ-Auxiliaries

Two similar tridentate directing groups derived from glycine and 8-aminoquinoline were shown to enable the palladium-catalyzed anti-Markovnikov hydrofunctionalization of 4-pentenylamine with drastically different efficiencies. A computational investigation into the origin of the reactivity difference between these isomeric, carbonyl-transposed auxiliaries suggests that protonation state, thus charge of the substrate-metal complex prior to nucleopalladation is key. These investigations have culminated in a directing group design that can undergo Pd-catalyzed hydrofunctionalization under relatively mild conditions, as low as room temperature.     

Catalytic Asymmetric Addition of Diorganozinc Reagents to Pyrazole-4,5-Diones and Indoline-2,3-Diones

The catalytic enantioselective diorganozinc additions to cyclic diketones including pyrazolin-4,5-diones and isatins have been developed. In the presence of morpholine-containing chiral amino alcohol ligand, the corresponding chiral cyclic tertiary alcohols were produced in good to excellent yields (up to 97 %) and enantioselectivities (up to 95 % ee). The notable feature of this protocol includes its mild reaction conditions, Lewis acid additives free and broad functional group tolerance.     

Tuning Tetrazole Photochemistry for Protein Ligation and Molecular Imaging

Photochemistry provides a wide range of alternative reagents that hold potential for use in bimolecular functionalisation of proteins. Here, we report the synthesis and characterisation of metal ion binding chelates derivatised with disubstituted tetrazoles for the photoradiochemical labelling of monoclonal antibodies (mAbs). The photophysical properties of tetrazoles featuring extended aromatic systems and auxochromic substituents to tune excitation toward longer wavelengths (365 and 395 nm) were studied. Two photoactivatable chelates based on desferrioxamine B (DFO) and the aza-macrocycle NODAGA were functionalised with a tetrazole and developed for protein labelling with ⁸⁹Zr, ⁶⁴Cu and ⁶⁸Ga radionuclides. DFO-tetrazole ( 1 ) was assessed by direct conjugation to formulated trastuzumab and subsequent radiolabelling with ⁸⁹Zr. Radiochemical studies and cellular-based binding assays demonstrated that the radiotracer remained stable in vitro retained high immunoreactivity. Positron emission tomography (PET) imaging and biodistribution studies were used to measure the tumour specific uptake and pharmacokinetic profile in mice bearing SK-OV-3 xenografts. Experiments demonstrate that tetrazole-based photochemistry is a viable approach for the light-induced synthesis of PET radiotracers.     

Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations

Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.