2,3-Diarylmaleate salts as a versatile class of diarylethenes with a full spectrum of photoactivity in water.

There is incessant interest in the transfer of common chemical processes from organic solvents to water, which is vital for the development of bioinspired and green chemical technologies. Diarylethenes feature a rich photochemistry, including both irreversible and reversible reactions that are in demand in organic synthesis, materials chemistry, and photopharmacology. Herein, we introduce the first versatile class of diarylethenes, namely, potassium 2,3-diarylmaleates (DAMs), that show excellent solubility in water.

Rapid, room-temperature self-organization of polyarylated 1-pyrroles from acetylenes and nitriles in the KOBu/DMSO system.

We have discovered that three molecules of arylacetylene are rapidly (15 min) assembled with one molecule of nitrile at room temperature in the KOBu/DMSO system to afford 2-aryl-3-arylethynyl-4-aryl-5-benzyl-1-pyrroles in up to 76% yield. We assume that this unprecedented self-organization process involves the cascade addition of acetylenic carbanions, first to the CN, then to the CC and CC bonds of the intermediates, followed by pyrrole ring closure the intramolecular nucleophilic addition of the NH functional group to the CC bond of the final intermediates.

Dihydropyrrole-3-thiones: one-pot synthesis from propargylamines, acyl chlorides and sodium sulfide.

An efficient one-pot synthesis of 1,2,5-trisubstituted-1,2-dihydro-3-pyrrole-3-thiones (up to 91% yield), representatives of essentially new heterocyclic systems, by the successive treatment of available propargylamines with acyl chlorides (PdCl/CuI/PhP/EtN, toluene, 40-45 °C, 3 h) and sodium sulfide (NaS·9HO, EtOH, 20-25 °C, 7 h) has been developed. The synthesis comprises the addition of sulfide anions to the formed aminoacetylenic ketones followed by dehydrative cyclization of the prototropically rearranged adducts.

Game of Aliphatics: A Density Functional Theory Study of Base-Catalyzed Substrate-Controlled Dimerizations of Aliphatic Alkynones.

The present work focuses on a comprehensive density functional theory (DFT) study of newly discovered base-catalyzed substrate-controlled dimerizations of aliphatic alkynones. In order to understand the origin of selectivity of the cascade assemblies of 6-methylene-5-oxaspiro[2.4]heptanones and 2-alkenylfurans, structural and electronic properties of neutral and deprotonated alkynone molecules, thermodynamic and kinetic characteristics of the deprotonation of alkynones having diverse C-H active substituents at the carbonyl function under the action of a base, and thermodynamic and kinetic characteristics of possible mechanisms of the discussed cascade reactions were theoretically assessed.

Electrooxidation of Hypercoordinated Derivatives of Silicon and Reactivity of Their Electrogenerated Cation Radicals: 1-Substituted Silatranes.

Electrochemical oxidation of 1-R-substituted silatranes (R = Me, vinyl, (CH)CN, CHPh, CH(CH), Ph, CHMe, -Cl-CH, Cl)-classical representatives of pentacoordinated silicon compounds-and the formation of their short living cation radicals upon reversible or quasi-reversible one-electron withdrawal were studied by means of cyclic and square-wave voltammetry, faradaic impedance spectroscopy and real-time temperature-dependent EPR spectroelectrochemistry supported by DFT B3PW91/6-311++G(d,p) (C-PCM, acetonitrile) calculations. The main reaction responsible for the decay of is shown to be their deprotonation, and ways of increasing the stability of these species are proposed.

Light-Induced Dyotropic Rearrangement of Diarylethenes: Scope, Mechanism, and Prospects.

Irreversible two-photon photorearrangement of 1,2-diarylethenes is a unique process providing access to complex 2a ,5a-dihydro-5,6-dithiaacenaphthylene (DDA) heterocyclic core. This reaction was serendipitously discovered during studies on photoswitchable diarylethenes and was initially considered as a highly undesired process. However, in recent years, it has been recognized as an efficient photochemical reaction, interesting by itself and as a promising synthetic method for the synthesis of challenging molecules.

O nuclear magnetic resonance: Recent advances and applications.

The present review is focused on the most recent achievements in the application of liquid phase O nuclear magnetic resonance (NMR) to inorganic, organic, and biochemical molecules focusing on their structure, conformations, and (bio)chemical behavior. The review is composed of four basic parts, namely, (1) simple molecules; (2) water and hydrogen bonding; (3) metal oxides, clusters, and complexes; and (4) biological molecules. Experimental O NMR chemical shifts are thoroughly tabulated.

Water-Soluble Nanocomposites Containing CoO Nanoparticles Incorporated in Poly-1-vinyl-1,2,4-triazole.

New water-soluble nanocomposites with cobalt oxide nanoparticles (CoONPs) in a poly(1-vinyl-1,2,4-triazole) (PVT) matrix have been synthesized. The PVT used as a stabilizing polymer matrix was obtained by radical polymerization of 1-vinyl-1,2,4-triazole (VT). The polymer nanocomposites with CoO nanoparticles were characterized by ultraviolet-visible, Fourier-transform infrared spectroscopy, atomic absorption spectroscopy, transmission electron microscopy, dynamic light scattering, gel permeation chromatography, and simultaneous thermogravimetric analysis.

Synthesis and DC Electrical Conductivity of Nanocomposites Based on Poly(1-vinyl-1,2,4-triazole) and Thermoelectric Tellurium Nanoparticles.

In this work, the structural characteristics and DC electrical conductivity of firstly synthesized organic-inorganic nanocomposites of thermoelectric Te nanoparticles (1.4, 2.8, 4.

New efficient pecS- ( = 1, 2) basis sets for quantum chemical calculations of P NMR chemical shifts.

The basis sets that are used in the quantum chemical calculations of P NMR chemical shifts have always been one of the most important factors of accuracy. Regardless of what high-quality approach is employed, using basis sets of insufficient flexibility in the important angular regions may give poor results and lead to misassignments of the signals in the P NMR spectra. In this work, it was found that the existing nonrelativistic basis sets for phosphorus atom of double- and triple- quality, specialized for the P NMR chemical shifts calculations, are essentially undersaturated in the -angular space that occurred to play a significant role in the overall accuracy of these calculations.

New 3-Aminopropylsilatrane Derivatives: Synthesis, Structure, Properties, and Biological Activity.

The biologically active compound 3-aminopropylsilatrane (a compound with a pentacoordinated silicon atom) underwent an aza-Michael reaction with various acrylates and other Michael acceptors. Depending on the molar ratio, the reaction yielded Michael mono- or diadducts (11 examples) containing functional groups (silatranyl, carbonyl, nitrile, amino, etc.).

Structural applications of the isotropic liquid-phase deuterium nuclear magnetic resonance.

Present review is focused on recent experimental and computational advances of the liquid-phase deuterium nuclear magnetic resonance (NMR). Nowadays, isotropic liquid-phase H NMR became one of the most important instruments for the identification and certification of organic compounds of biological interest together with natural products and biosynthetic molecules. Of special interest are the H NMR biochemical and microbiological applications.

Detection of gene clusters for biodegradation of alkanes and aromatic compounds in the Rhodococcus qingshengii VKM Ac-2784D genome.

Bacterial species of the genus Rhodococcus are known to be efficient degraders of hydrocarbons in contaminated soil. They are also employed for bioremediation of polluted environments. These bacteria are widely met in soil, water and living organisms.

Design of novel water-soluble isoxazole-based antimicrobial agents and evaluation of their cytotoxicity and acute toxicity.

Based on the readily available 3-organyl-5-(chloromethyl)isoxazoles, a number of previously unknown water-soluble conjugates of isoxazoles with thiourea, amino acids, some secondary and tertiary amines, and thioglycolic acid were synthesized. The bacteriostatic activity of aforementioned compounds has been studied against Enterococcus durans B-603, Bacillus subtilis B-407, Rhodococcus qingshengii Ac-2784D, and Escherichia coli B-1238 microorganisms (provided by All-Russian Collection of Microorganisms, VKM). The influence of the nature of the substituents in positions 3 and 5 of the isoxazole ring on the antimicrobial activity of the obtained compounds has been determined.

- and -Phosphorylated Enamines-An Avenue to Heterocycles: NMR Spectroscopy.

The review presents extensive data (from the works of the author and literature) on the structure of - and -chlorophosphorylated enamines and the related heterocycles obtained by multipulse multinuclear H, C, and P NMR spectroscopy. The use of phosphorus pentachloride as a phosphorylating agent for functional enamines enables the synthesis of various - and -phosphorylated products that are heterocyclized to form various promising nitrogen- and phosphorus-containing heterocyclic systems. P NMR spectroscopy is the most convenient, reliable and unambiguous method for the study and identification of organophosphorus compounds with different coordination numbers of the phosphorus atom, as well as for the determination of their - and -isomeric forms.

Novel Route to Cationic Palladium(II)-Cyclopentadienyl Complexes Containing Phosphine Ligands and Their Catalytic Activities.

The Pd(II) complexes [Pd(Cp)(L)][BF] were synthesized via the reaction of cationic acetylacetonate complexes with cyclopentadiene in the presence of BF∙OEt ( = 2, = 1: L = PPh (), P(-Tol), (-methoxyphenyl)phosphine (TOMPP), -2-furylphosphine, -2-thienylphosphine; = 1, = 1: L = dppf, dppp (), dppb (), 1,5-bis(diphenylphosphino)pentane; = 1, = 2 or 3: 1,6-bis(diphenylphosphino)hexane). Complexes - were characterized using X-ray diffractometry. The inspection of the crystal structures of the complexes enabled the recognition of (Cp)⋯(Ph-group) and (Cp)⋯(CH-group) interactions, which are of C-H…π nature.

Quantum-Chemical Study of the Assembly Mechanism of 1-Pyrrolines from -Benzylaldimines and Arylacetylenes in KOBu/DMSO Superbasic Medium.

By using a quantum-chemical approach, B2PLYP-D2/6-311+G**//B3LYP/6-31+G*, we have carried out a detailed study of the assembly of 1-pyrrolines from -benzyl-1-phenylmethanimine and phenylacetylene in the superbasic medium KOBu/dimethyl sulfoxide (DMSO). In this way, we have considered, both theoretically and experimentally, the mechanisms of the assembly through a concerted and stepwise nucleophilic cycloaddition and have addressed the side processes accompanying the assembly. It is found that the assembly via the concerted cycloaddition is kinetically more favorable than that via the stepwise cycloaddition.

New pecJ- ( = 1, 2) Basis Sets for Selenium Atom Purposed for the Calculations of NMR Spin-Spin Coupling Constants Involving Selenium.

We present new compact pecJ- ( = 1, 2) basis sets for the selenium atom developed for the quantum-chemical calculations of NMR spin-spin coupling constants (SSCCs) involving selenium nuclei. These basis sets were obtained at the second order polarization propagator approximation with coupled cluster singles and doubles amplitudes (SOPPA(CCSD)) level with the property-energy consistent (PEC) method, which was introduced in our previous papers. The existing SSCC-oriented selenium basis sets are rather large in size, while the PEC method gives more compact basis sets that are capable of providing accuracy comparable to that reached using the property-oriented basis sets of larger sizes generated with a standard even-tempered technique.

Gas-Phase Structure of 3,7,9-tris(trifluoromethylsulfonyl)-3,7,9-triazabicyclo[3.3.1]nonane by GED and Theoretical Calculations.

The molecular structure and conformational and rotational composition of 3,7,9-tris(trifluoromethylsulfonyl)-3,7,9-triazabicyclo[3.3.1]nonane have been investigated by synchronous gas-phase electron diffraction/mass spectrometry GED/MS and theoretical calculations (B3LYP and M06-2X with cc-pVTZ and aug-cc-pVTZ basis sets) and compared to the X-ray structure.

Multifunctional fluorescent diarylethene: time-resolved study of photochemistry.

A study of luminescence and photochromic properties of ()-2,3-bis(2,5-dimethylthiophen-3-yl)-5-(4-(pyrrolidin-1-yl)benzylidene)cyclopent-2-en-1-one, which is a diarylethene with a push-pull system between carbonyl and dimethylamino groups, was performed using time-resolved methods. The intramolecular charge transfer (ICT) process as well as 6π-electrocyclization and -/-isomerization contribute to the complex light-induced properties of this molecule. Formation of unexpected short-lived intermediates was detected in the time range from 100 fs to 100 μs.

On the Utmost Importance of the Basis Set Choice for the Calculations of the Relativistic Corrections to NMR Shielding Constants.

The investigation of the sensitivity of the relativistic corrections to the NMR shielding constants (σ) to the configuration of angular spaces of the basis sets used on the atoms of interest was carried out within the four-component density functional theory (DFT). Both types of relativistic effects were considered, namely the so-called heavy atom on light atom and heavy atom on heavy atom effects, though the main attention was paid to the former. As a main result, it was found that the dependence of the relativistic corrections to σ of light nuclei (exemplified here by H and C) located in close vicinity to a heavy atom (exemplified here by In, Sn, Sb, Te, and I) on the basis set used on the light spectator atom was very much in common with that of the Fermi-contact contribution to the corresponding nonrelativistic spin-spin coupling constant ().

Structural and theoretical study of π-stacking interactions in new complexes based on CuCl and 3-sulfonamide-substituted imidazo[2,1-b]thiazoles.

Context: At present, sulfonamides and their metal complexes have received a new impetus for development. Of particular interest is the study of molecular and crystal structures, which takes into account weak non-valent interactions. Despite the low energy of such interactions, in many cases, they act collectively, and the sum of their actions can play a significant role.

Reactions of α-Functionally Substituted Enals with Terminal Alkynes: Unexpected Assembly of 2-Amino-2-Cyclopentenones.

The reactions of α-chalcogen, α-halo, or α-amino functionally substituted enals with terminal alkynes leading either to corresponding propargyl alcohols (for O-, S-, Cl-, and Br-bearing substrates) or unexpected 2-amino-2-cyclopentenones (for aminoenals) are described. The key feature of these reactions is the rearrangement of adducts bearing amino groups on silica gel that triggered further cyclization to five-membered carbocycles.

Stereochemical Study of the Super Large Tetrakis Alkaloid Alasmontamine A by Means of an Advanced Computational NMR.

H and C NMR chemical shifts of the tetrakis monoterpene indole alkaloid alasmontamine A, with a molecular formula of CHNO, have been calculated within the DFT framework. Six minimum energy conformers of this alkaloid were identified, and three key configurations that contribute to its NMR shielding constants were established. Several ambiguities in the reported assignment of the NMR chemical shifts of alasmontamine A have been resolved.