Ab initio investigation on the mechanism of SO activation by P/B intermolecular frustrated Lewis pairs.

Context: In silico study investigates the activation of sulfur dioxide by newly designed frustrated Lewis pairs, i.e., [P(Bu)…B(CNBSHF)], where the Lewis acid part is a super Lewis acid.

In Silico Investigation of the Mechanism of Disulfide Bond Dissociation by New Frustrated Lewis Pairs.

Understanding the mechanism of disulfide bond cleavage is important in various scientific disciplines including organic synthesis, catalysis, and biochemistry. In this study, an in silico investigation has been carried out for the dissociation of disulfide bonds using newly designed frustrated Lewis pairs (FLPs). The study revealed that the cleavage of the disulfide bond by the FLP P(Bu)/B(CNBSHF) can also be used like the conventional FLP (Bu)P/B(CF).

Insights into the catalytic activity of boron-doped thiazoles in the Diels-Alder reaction.

The role of boron-doped thiazoles as a Lewis acid catalyst in [4+2] cycloaddition reaction between 1,3-butadiene and acrolein has been addressed. Three different organic heterocycles were designed to study their catalytic activity. It has been observed that these heterocycles efficiently work as catalysts than the well-known Lewis acid BF.

Concept-Driven Chemoselective O/N-Derivatization of Prolinol: A Bee-Line Approach to Access Organocatalysts.

An investigation into the sensitivity of reaction conditions to a highly utilized protocol has been reported, wherein the mono-Boc functionalization of prolinol could be controlled for the exclusive synthesis of either -Boc, -Boc, or oxazolidinone derivatives. Mechanistic investigation revealed that the elementary steps could possibly be controlled by (a) a requisite base to recognize the differently acidic sites (NH and OH) for the formation of the conjugate base, which reacts with the electrophile, and (b) the difference in nucleophilicity of the conjugate basic sites. Herein, a successful chemoselective functionalization of the nucleophilic sites of prolinol by employing a suitable base is reported.

Functionalized nona-silicide [SiR] Zintl clusters: a new class of superhalogens.

Superatoms, due to their various applications in redox and materials chemistry, have been a major topic of study in cluster science. Superhalogens constitute a special class of superatoms that mimic the chemistry of halogens and serve as building blocks of novel materials such as super and hyper salts, perovskite-based solar cells, solid-state electrolytes, and ferroelectric materials. These applications have led to a constant search for new class of superhalogens.

Role of Size and Composition on the Design of Superalkalis.

Superalkalis and superhalogens are atomic clusters that mimic the chemistry of alkali and halogen atoms, respectively; the ionization energies of the superalkalis are less than those of alkali atoms, while the electron affinities of superhalogens are larger than those of the halogen atoms. These superions can serve as the building blocks of a new class of supersalts with applications in solar cells, metal-ion batteries, multiferroic materials, and so on. While considerable progress has been made in the design and synthesis of superhalogens, a similar understanding of superalkalis is lacking.

Zintl Lewis Superacids: Al(GeL) (L = H, CH, CHO, CN).

In quest of a Zintl ion-based Lewis superacids, Al(GeL) {L= H, CH, CHO and CN} compounds have been designed and their properties have been studied within the framework of conceptual density functional theory-based reactivity descriptors. Superacid property has been identified for these complexes as per the fluoride ion affinity (FIA) values. Studies reveal that Al[Ge(CN)] and Al[Ge(CH)] behave like superacids as their FIA exceeds the value of SbF, which is considered as the strongest Lewis acid.

Active Bromoaniline-Aldehyde Conjugate Systems and Their Complexes as Versatile Sensors of Multiple Cations with Logic Formulation and Efficient DNA/HSA-Binding Efficacy: Combined Experimental and Theoretical Approach.

Two fluorescence active bromoaniline-based Schiff base chemosensors, namely, ()-4-bromo-2-(((4-bromophenyl)imino)methyl)phenol ( ) and ()-2-(((4-bromophenyl)imino)methyl)phenol ( ), have been employed for the selective and notable detection of Cu and Zn ions, respectively, with the simultaneous formation of two new metal complexes [Cu(L)] and [Zn(L)] . X-ray single crystal analyses indicate that complexes and are tetra-coordinated systems with substantial CH..

Unraveling the origin of interactions of hydroxychloroquine with the receptor-binding domain of SARS-CoV-2 in aqueous medium.

Interactions of hydroxychloroquin (HCQ) with the receptor binding domain (RBD) of SARS-CoV-2 were studied from atomistic simulation and ONIOM techniques. The key-residues of RBD responsible for the human transmission are recognized to be blocked in a heterogeneous manner with the favorable formation of key-residue:HCQ (1:1) complex. Such heterogeneity in binding was identified to be governed by the differential life-time of the hydrogen bonded water network anchoring HCQ and the key-residues.

Density Functional Treatment on Alkylation of a Functionalized Deltahedral Zintl Cluster.

Density functional theory (DFT) is one of the popular methods to understand the electronic structure of molecular systems based on electronic density. On the basis of this theory, several conceptual DFT descriptors have been developed which can deal with the stability, reactivity, and several other physicochemical properties of molecules. Here, we have taken a nine-atom-functionalized deltahedral Zintl cluster of germanium (Ge) to examine the alkylation reaction mechanism.

Cycloaddition Reactions between HC = CHR (R = H, CN, CH) and a Cyclic P/B Frustrated Lewis Pair: A DFT Study.

The cycloaddition of ethylene, cyanoethylene, and propylene to a five-membered P/B frustrated Lewis pair (FLP) is shown to be highly favorable under normal conditions, as confirmed by the computed thermodynamic and kinetic data. All of these cycloaddition reactions are concerted as highlighted by the intrinsic reaction coordinate (IRC) and Wiberg bond index calculations. Almost 70% of the reaction force is required for structural orientation to initiate electronic activity.

Oxidation-Induced Differentially Selective Turn-On Fluorescence via Photoinduced Electron Transfer Based on a Ferrocene-Appended Coumarin-Quinoline Platform: Application in Cascaded Molecular Logic.

Differentially selective molecular sensors that exhibit differential response toward multiple analytes are cost-effective and in high demand for various practical applications. A novel, highly differentially selective electrochemical and fluorescent chemosensor, , based on a ferrocene-appended coumarin-quinoline platform has been designed and synthesized. Our designed probe is very specific toward Fe via a reversible redox process, whereas it detects Cu via irreversible oxidation.

Cationic Organic Nanoaggregates as AIE Luminogens for Wash-Free Imaging of Bacteria and Broad-Spectrum Antimicrobial Application.

The increase in the use of bactericides is a matter of grave concern and a serious threat to human health. The present situation demands rapid and efficient detection and elimination of antibiotic-resistant microbes. Herein, we report the synthesis of a simple -symmetric molecular system (TGP) with an intrinsic positive charge through a single-step Schiff base condensation.

Designing aromatic heterocyclic superacids in terms of Brønsted and Lewis perspectives.

The unexplored area of organic superacids was investigated in terms of both Brønsted and Lewis concepts of acids and bases. The primary requirement of a superacid-high affinity for electron/fluoride ions was fulfilled using two strategies: (i) using the superhalogen-type heterocyclic framework and (ii) selecting systems that have an electron count one short of attaining (4n + 2) Hückel aromaticity. With these in mind, eleven systems were considered throughout the study, expected to cross the target of 100% HSO acidity and/or the fluoride affinity of SbF.

Insights into the activation process of CO through Dihydrogenation reaction.

Based on first principle calculation, activation of CO has been analyzed thoroughly by using different conceptual density functional theory based descriptors like reaction force, reaction force constant, reaction electronic flux, dual descriptor, etc. via dihydrogenation reaction of BN, H and CO. The total reaction is a two-step reaction where initially BNH is formed from the reaction between BN and H and in the second step HCOOH is form due to the reaction of CO by BNH.

Ligand stabilization of manganocene dianions - in defiance of the 18-electron rule.

Manganocene [Mn(C5H5)2], a 17-electron system, is expected to have a high electron affinity, as addition of an extra electron would make it a closed-shell 18-electron system. Surprisingly, it has a very low electron affinity of only 0.28 eV.

Unique reactivity of B in B[GeY] (Y = H, CH, BO, CN): formation of a Lewis base.

Boron compounds usually exhibit Lewis acidity at the boron center due to the presence of vacant p-orbitals. We show that this chemistry can be altered by an appropriate choice of ligands to decorate the boron center. To elucidate this effect, we studied the interactions of boron with two classes of ligands, one based on penta-substituted phenyl species (CX, X = F, BO, CN) and the other based on Zintl-ion-based groups (GeY, Y = H, CH, BO, CN).

Tailoring the properties of manganocene: formation of magnetic superalkali/superhalogen.

A new magnetic superalkali/superhalogen molecule based on the sandwich complex manganocene is reported. The hydrogen atoms of the cyclopentadienyl rings are periodically substituted with electron-donating and electron-withdrawing ligands (or both) to design substituted manganocene complexes. The substituted manganocene complexes exhibit the properties of superalkali and/or superhalogen depending on the nature of the substituents.

Superhalogens as Building Blocks of Super Lewis Acids.

Lewis acids play an important role in synthetic chemistry. Using first-principle calculations on some newly designed molecules containing boron and organic heterocyclic superhalogen ligands, we show that the acid strength depends on the charge of the central atom as well as on the ligands attached to it. In particular, the strength of the Lewis acid increases with increasing electron withdrawing power of the ligand.

A New Class of Superhalogen Based Anion Receptor in Li-Ion Battery Electrolytes.

In the search for new additives (anion receptors) in Li-ion battery electrolytes especially for LiPF and LiClO, we have theoretically designed boron-based complexes by coupling with different heterocyclic ligands. The validation of the formation of modeled compounds involves reproduction of available experimentally reported absolute magnetic shielding and chemical shift values for different boron complexes. As compared to the commonly used tris(pentafluorophenyl) borane, our designed compounds suggest that the complexes like B[CHBNO(CN)], B[CHBNS(CN)], and B[CHBN(CN)] are promising additives.

Synthesis, characterization and nucleic acid binding studies of mononuclear copper(II) complexes derived from azo containing O, O donor ligands.

Azo linked salicyldehyde and a new 2-hydroxy acetophenone based ligands (HL and HL) with their copper(II) complexes [Cu(L)] (1) and [Cu(L)] (2) were synthesized and characterized by spectroscopic methods such as H, 13C NMR, UV-Vis spectroscopy and elemental analyses. Calculation based on Density Functional Theory (DFT), have been performed to obtain optimized structures. Binding studies of these copper (II) complexes with calf thymus DNA (ct-DNA) and torula yeast RNA (t-RNA) were analyzed by absorption spectra, emission spectra and Viscosity studies and Molecular Docking techniques.

Zintl superalkalis as building blocks of supersalts.

Alkali metal cations and halogen anions are common components of ionic salts. Recently, a new class of salts termed supersalts was reported, each of which contains a superalkali and a superhalogen that mimic an alkali metal cation and a halogen anion, respectively. Using three different functionals, namely B3LYP, wB97X, and M06-2X, we theoretically investigated a new subset of supersalts composed of Zintl-based superalkalis and inorganic superhalogens via computational modeling.

Deltahedral Organo-Zintl Superhalogens.

Zintl ions constitute a special type of naked anionic clusters, mainly consisting of Group 13, 14, and 15 elements of the Periodic Table. Due to the presence of multiple negative ions, the chemistry of Zintl ions is unique. They not only form Zintl phases with alkali and alkaline-earth metal cations, but also form organo-Zintl clusters with distinct properties.