Abstract The present work describes the synthesis, characterization, and application of a new ion‐tagged iron catalyst. catalyst was employed in Biginelli reaction with impressive performance. High yields have been achieved when carried out imidazolium‐based ionic liquids (BMI ⋅ PF 6 , BMI NTf 2 BF 4 ), thus showing that ionic‐liquid effects play role reaction. Moreover, could be recovered reused up to eight times without any noticeable loss activity. Mechanistic studies performed by using...

This paper describes the use of common Lewis acids supported in imidazolium-based ionic liquids as catalysts to promote Biginelli reaction. The liquid effect and reaction mechanism are discussed on basis nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS), theoretical calculations. Indeed, results showed that medium plays a fundamental role synthesis biologically active dihydropyrimidinones due stabilization charged intermediates proposed mechanism. When...

Bronsted and Lewis acid catalysts with ionic tags under homogeneous heterogeneous conditions have been tested to perform the Biginelli synthesis of 3,4-dihydropyrimidin-2(1H)-one (DHPMs). Metal-containing liquids were evaluated as reasonable results (homogeneous systems). Heterogeneous (zeolite β H3PW12O40 supported on zeolite β) tested, well, good excellent results. The use a functionalized liquid heteropolyacid in anion moiety system) gave best using no excess three reagents. preferred...

The current manuscript describes the role and importance of catalysis solvent effects for Biginelli multicomponent reaction. overwhelming number new catalysts conditions recently published synthesis, including in some manuscripts entitled "catalyst-free" and/or "solvent-free" have incentivized controversies hot debates regarding developing reaction to perform this very important These so-called reports generated much confusion field, requiring urgent elucidations. In manuscript, we...

To account for frequently documented low-temperature deviations from Arrhenius rate law, the proposed expansion of inverse activation energy against temperature is shown to yield a first order linearizing parameter which formally correlated with Tsallis non-extensive classical statistical mechanics. Its sign provides heuristic criterion, especially appealing in biochemistry, assigning as due either: (i) quantum mechanical under-barrier tunneling, or (ii) 'classical' collective phenomena. For...

The OH + HBr → H2O Br reaction, prototypical of halogen-atom liberating processes relevant to mechanisms for atmospheric ozone destruction, attracted frequent attention experimental chemical kinetics: the nature unusual reactivity drop from low high temperatures eluded a variety theoretical efforts, ranking this one among most studied four-atom reactions. Here, inspired by oriented molecular-beams experiments, we develop first-principles stereodynamical approach. Thermalized sets...

The interest for novel chalcone-based materials in nonlinear optics is dependent on strong second harmonic generation organic systems.

The mechanism of the Ugi four-component reaction has been investigated by electrospray ionization (tandem) mass spectrometry using charge-tagged reagents (a carboxylic acid or an amine) to favour detection. Key intermediates were transferred directly via ESI(+) from solution gas phase and characterized MS measurements MS/MS collision induced dissociation. Mumm rearrangement (final step) was also both travelling wave ion mobility DFT calculations. data seem consolidate amazingly selective...

We calculated the nonlinear optical properties of 24 azo-enaminone derivatives, incorporating solvent effects on their geometric and electronic structure, to assess impact environment these properties. Namely, we incorporated chloroform, tetrahydrofuran, acetone, ethanol, methanol, dimethyl sulfoxide in our calculations compared results with gas-phase calculations. To account for electron correlation NLO properties, performed at MP2/6-31G(p)//MP2/6-31G(d) level set. The polarizable continuum...

A formulation is presented for the application of tools from quantum chemistry and transition-state theory to phenomenologically cover cases where reaction rates deviate Arrhenius law at low temperatures. parameter introduced describe deviation systems reaching thermodynamic limit identified as linearizing coefficient in dependence inverse activation energy with temperature. Its physical meaning given when can be ascribed mechanical tunneling its value calculated explicitly. Here, a new...

The present manuscript describes the synthesis of two novel 2,1,3-benzothiadiazole (BTD) derivatives containing an excited state intramolecular proton transfer (ESIPT) site. Photophysical properties, X-ray analysis, ESIPT and charge-transfer (ICT) these fluorescent monosubstituted BTD were investigated. It is also shown that ICT can take place concomitantly. Theoretical calculations (ab initio DFT) corroborate high stability in due to efficient processes. Also, optimized calculated...

Abstract A series of new rationale designed 2,1,3‐benzothiadiazole (BTD) fluorescent derivatives has been synthesized and applied for cellular selective staining cancer cells in cell‐imaging experiments. Four BTD showed only poor or reasonable selection, but with excellent fluorescence intensity almost no background signal emitting at the blue green channels. The knowledge gained by analysing their molecular architecture, however, allowed planning synthesis a BTD, which was then successfully...

Two new benzothiadiazole-triazole-linked lapachone derivatives were designed, synthesized and characterized by 1D 2D NMR spectroscopy. Their photophysical properties also investigated. Theoretical calculations (DFT), based on the molecular design of compounds, allowed a better understanding derivatives' stability behaviour, especially in excited state. This manuscript describes discussion architecture which is two substitutions at positions 4- 7- important 2,1,3-benzothiadiazole (BTD) core....

The use of a charge-tagged acrylate derivative bearing an imidazolium tag to study the Morita-Baylis-Hillman reaction via ESI-MS(/MS) monitoring and effect such (imidazolium cations ion pairs) over TSs is described. ionic nature substrate was meant facilitate ESI transfer gas phase for direct mass spectrometric analysis. detection characterization charged intermediates has suggested major pathways. DFT calculations considering polar protic solvent (methanol), aprotic (acetonitrile), no (gas...

A novel lipophilic fluorescent small-molecule 2,1,3-benzothiadiazole derivative (named here as BTD-AO) was designed, synthesized, characterized and applied a live cell-imaging probe. Its cellular uptake dynamics at low temperature (4 °C) using MDA-MB-237 were investigated. Confocal bioimages revealed that the new bioprobe capable of easily transposing cell-membrane temperatures also BTD-AO over time. had high affinity for vesicles (lipid droplets) its subcellular location precisely...

Abstract We performed an ab initio molecular dynamics study with a nitrogen atom in the 1/2 spin state, which corresponds to excited electronic contrast ground state 3/2 state. This N was encapsulated H 2 molecule C70 fullerene, as “nanoflask” for experimentation. approach initially proposed by Morinaka and colleagues (Angew. Chem. Int. Ed. 2017, 56, 6488–6491), where they demonstrated, using spectroscopy, that N( 4 S ) atom, does not react molecule. By analyzing trajectory from...

Thermodynamic stability of nanoparticles necessitates the use stabilizing agents to provide steric and electronic protection. Nevertheless, their activity selectivity remain suboptimal under moderate reaction conditions. In this study,...

Among four-atom processes, the reaction OH + HBr → H2O Br is one of most studied experimentally: its kinetics has manifested an unusual anti-Arrhenius behavior, namely, a marked decrease rate constant as temperature increases, which intrigued theoreticians for long time. Recently, salient features potential energy surface have been characterized and kinetic aspects can be considered satisfactorily reproduced by classical trajectory simulations. Motivation work reported in this paper...

In the present manuscript, a novel fluorescent chalcone derivative is synthesized and its photophysical properties are fully characterized. The designed fluorophore applied as probe to study protein-dye interactions with bovine serum albumin. Circular dichroism gave interesting results on thermodynamics of interaction. NMR spectroscopy, especially relaxation measurements, revealed atoms in that interacts protein upon binding. Molecular docking calculations indicate most favourable binding...

The current article describes the synthesis, characterization, and application of a designed hybrid fluorescent BTD-coumarin (2,1,3-benzothiadiazole-coumarin) derivative (named BTD-Lip). use BTD-Lip for live-cells staining showed excellent results, lipid droplets (LDs) could be selectively stained. When compared with commercially available dye (BODIPY) LD staining, it was noted that fluorescence capable considerable larger number LDs in both live fixed cells (ca. 40% more). new also tested...

Novel designed 2,1,3-benzothiadiazole fluorescent probes were synthesized, characterized and applied as live cell fluorescence imaging probe staining only mitochondria in mammalian cancer lines (MCF-7). The efficiency of these new was found to be much superior that the commercially available MitoTracker® Red. Cellular vitro experiments allowed better understanding relationship between planned molecular architecture dyes observed cellular selectivity.

The OH + HCl → H 2 O Cl reaction is one of the most studied four‐body systems, extensively investigated by both experimental and theoretical approaches. Here, as a continuation our previous work on HBr HI reactions, which manifest an anti ‐Arrhenius behavior that was explained stereodynamic roaming effects, we extend strategy to understand transition sub occurring for case. As previously, perform first‐principles on‐the‐fly Born–Oppenheimer molecular dynamics calculations, thermalized at...

Well-defined structure-property relationships offer a conceptual basis to afford priori design principles develop novel π-conjugated molecular and polymer materials for nonlinear optical (NLO) applications. Here, we introduce the bond ellipticity alternation (BEA) as robust parameter assess NLO characteristics of organic chromophores illustrate its effectiveness in case streptocyanines. BEA is based on symmetry electron density, physical observable that can be determined from experimental...