Symmetrical Derivatives Research Articles

Incompatibility in quantum parameter estimation

In this paper we introduce a measure of genuine quantum incompatibility in the estimation task of multiple parameters, that has a geometric character and is backed by a clear operational interpretation. This measure is then applied to some simple systems in order to track the effect of a local depolarizing noise on the incompatibility of the estimation task. A semidefinite program is described and used to numerically compute the figure of merit when the analytical tools are not sufficient, among these we include an upper bound computable from the symmetric logarithmic derivatives only. Finally we discuss how to obtain compatible models for a general unitary encoding on a finite-dimensional probe.

Re-enter the syn-(Me,I)Bimane: A Gateway to Bimane Derivatives with Extended π-Systems

Abstract syn-α-Diiodobimane (syn-(R2,I)B) is a key intermediate for the derivatization of the bimane core in the α-positions. Here we describe an expeditious method to prepare symmetric α-bimane derivatives, such as syn-(R2,I)B, as well as unsymmetric ones. Our strategy turns the synthesis of α derivatives with extended π-systems practical and affordable. We applied this approach to the synthesis of ethynylbenzaldehyde bearing bimanes as potential selective probes for aldolase class I enzymes.

Preparation of glycosyl disulfides and sulfides via the formation of glycosyl Bunte salts as thiol surrogates

A convenient odourless reaction condition has been developed for the preparation of symmetrical glycosyl disulfide derivatives and aryl glycosyl disulfide derivatives from corresponding glycosyl iodides via in situ formation of glycosyl Bunte salts as thiol surrogates. The reaction has been further extended towards the preparation of glycosyl sulfides derivatives from corresponding Bunte salt in the presence of sodium sulphide. Most of the reactions were high yielding and suitable for scaling up.

Synthesis of C3-Symmetric Triazine-Based Derivatives: Study of their AIEE, Mechanochromic Behaviors, and Detection of Picric Acid and Uric Acid in Aqueous Medium

A smart accessible D-A with a tripod shape of triazine derivatives such as TZOME, TZSET, and TZNET was synthesized through simple Suzuki–Miyaura coupling and cyano cyclization reaction. Remarkably, TZNET has excellent optical properties compared to TZOME and TZSET. In particular, TZNET exhibits enhanced emission, induced through aggregation and mechanochromic luminescence. More interestingly, AIEE-fluorescent TZNET has a turnoff fluorescence sensor for picric acid with an LOD of 203 nM and a turn-on sensor for uric acid with an LOD of 209 nM. To the best of our knowledge, this is the first dual-coupled sensor for picric acid and uric acid in an aqueous medium.

An ethyl thioglycolate-based chemosensor: Spectrophotometric detection of Fe3+ and fluorometric detection of Hg2+ with high selectivity

A novel symmetric bianthracene derivative (D2) containing one benzene ring and two ethyl thioglycolates connecting to the benzene ring on both sides of the bianthracene unit was designed and synthesized. D2 can detect Fe3+ and Hg2+ in acetonitrile/water (6:4, v/v) solution via different changes of absorbance and fluorescence in the pH range from 3 to 10. D2 exhibits high colorimetric sensitivity for Fe3+ with low detection limit (1.87 × 10−5 mol/L). The absorbance intensity of D2 in acetonitrile/water solution show a linear response to Fe3+ in the wide concentration range of 0 –1000 μM, which is beneficial for quantitative analysis. D2 also displays highly selective fluorescent sensing for Hg2+ with a low detection limit of 1.07 µM over other metal ions and can accurately detect the existence of Hg2+ in water samples.

Numerical Study of Stochastic Leontief-Type Model with Impulses

ABSTRACT In this article, a stochastic Leontief model with impulses has been studied, which is represented by a system of stochastic differential-algebraic equations, in both sides of the rectangular constant numerical matrices that form a singular pencil. The system has been considered in terms of the current velocity of the solution, which is a direct analog of the physical velocity of deterministic processes. The proposed approach in this work does not impose restrictions on the size and the form of the matrices included in the Leontief-type system. The Kroenke-Weierstrass transformation of the pencil was conducted by the coefficient matrices to the canonical form has been used to simplify the study of equations. This study also involves two methods: Firstly, using a stochastic differential equation, this was followed by using the so-called mean derivatives of Nelson random processes to describe the solutions of this equation. The distinguishing feature of the work proposed an approach based on the convergence of the theoretical results to the exact one. The findings show that explicit formulas for solutions and solvability conditions are obtained, and for a subsystem resolved with respect to the symmetric derivative. The theorem of existence of solutions for the system under consideration has been proved under certain conditions on the coefficients of the system. Conducting computational experiments on the model confirming the effectiveness of the proposed approach. Error, maximum and minimum of the singular values of matrices.

Efficient and environmentally sustainable domino protocol for the synthesis of diversified dispiroheterocycles using 1-Butyl-3-methylimidazolium bromide [bmim]Br

An environmentally benign, simple, and efficient procedure has been developed for the construct of some symmetrical dispiroheterocycles derivatives by the reaction of the variety of 6-amino-2-thiouracil/6-aminouracil /2-amino-1,3,4-thiadiazole, isatins and p-toluidine in the presence of 1-Butyl-3-methylimidazolium bromide ([bmim]Br) as a solvent as well as catalyst at room temperature. In this study, a variety of bis-spiro-indoline-chromenes, pyranopyranes, imidazo-pyridines, pyrido-pyrimidines and pyridines were obtained with excellent yields within short reaction time and without chromatographic separation. Furthermore, the green catalytic system can be recycled specific times with no decreases in yields and reaction rates.

Multitarget Diallyl Disulfides (DADS) against Aβ Aggregation: Screening through Molecular Docking with Aβ42 & ZnII‐Aβ16, ADME, DFT & Synthetic Strategy

AbstractThe Aβ42 amyloid aggregation and its stabilization by coordination metals like ZnII through chelation, are the major pathological causes behind the occurrence of Alzheimer's disease (AD). Natural compounds like curcumin and chrysamine G have depicted Aβ42 aggregation inhibition, metal chelation and anti‐oxidant properties. Likewise garlic derived diallyl disulfide (DADS) has shown metal chelation, acetylcholinesterase (AChE) inhibition and antioxidant properties. In the present study a library of thirty four unnatural symmetrical DADS derivatives with aliphatic, aryl and new heteroaryl spacer groups, has been designed on the basis of electron releasing/withdrawing substituents and N/O heteroatom. The library was screened using various theoretical tools for their molecular properties and bioactivity with different receptors, to filter eleven potentially active derivatives. Further, Molecular docking study with Aβ42 (PDB ID: 1IYT) and ZnII‐Aβ16 (PDB ID: 1ZE9) displayed significant binding of heteroaryl DADS derivatives with highest binding energies and zinc binding ability. DFT calculations helped to predict their binding ability with free ZnII ion through disulfide linkage. MEP studies specified their reactive sites of binding. Finally, a synthetic protocol using less toxic reagents has been designed for their synthesis and an in vitro antioxidant activity has been evaluated.

Investigation of Triple Symmetric Non-halogen Benzene Derivative Solvent for Spray-Coated Polymer Solar Cells.

The performance of spray-coated polymer solar cells could be largely improved via morphologies and phase optimization by solvent engineering. However, there is still a lack of fundamental knowledge and know-how in controlling blend morphology by using various solvents. Here, the effect of adding low polar benzene and non-halogen benzene derivatives with triple symmetric molecular has been systematically investigated and discussed. It is found that the triple symmetric non-halogen benzene could promote the formation of preferential face-on molecule orientation for PBDB-T-2Cl:IT4F films by grazing incidence wide-angle X-ray scattering. The X-ray photoelectron spectroscopy shows that PBDB-T-2Cl could be transported to the surface of the blend film during drying process. A 3D opt-digital microscope shows that triple symmetric non-halogen benzene could also improve the morphologies of active layers by reducing the coffee ring or other micro-defects. Due to the appropriate vapor pressures, devices with mixing 20% benzene or the triple symmetric non-halogen in spray solution could significantly improve the device performance. Device prepared using 20% 1,3,5-trimethylbenzene (TMB) and 80% chlorobenzene (CB) mixture solvent has the best morphology and phase structure, and the power conversion efficiency (PCE) of the device was increased nearly 60 to 10.21% compared with the device using CB as the only solvent.

Synthesis, Electrochemistry, and Optical Properties of Highly Conjugated Alkynyl-Ferrocenes and -Biferrocenes

Sonogashira reactions are utilized herein to react iodo-ferrocenes and -biferrocenes with terminal alkyne ligands, functionalized with both pyridine and thioanisole groups. High-yielding reactions generate both monoalkynyl and dialkynyl derivatives, the ratio of which can be altered through changes in the reaction stoichiometry. This methodology allowed us to synthesize a large family of derivatives, comprising four symmetrical derivatives (3xx, where x represents a phenyl-substituted terminal alkyne) and six less-studied asymmetrical derivatives (3xy, where x and y represent two different phenyl-substituted terminal alkynes), as well as a number of their biferrocenyl analogues (6x, 7xx, and 7xy), including the first known examples of asymmetrically disubstituted biferrocenes. We examined the electrochemical behavior of all the systems in solution through the use of cyclic voltammetry and demonstrate that these highly conjugated alkynyl ligands exert delicate redox control over the central ferrocene motif. We also note that these substituents display some control over the mixed-valence character present in biferrocene monocations, with thioanisole substituents imparting almost an order of magnitude higher Kc than their pyridyl analogues, and asymmetric systems displaying rare characteristic properties of mixed-valence isomers. The electronic structure of these systems was further elucidated through a combination of UV/vis spectroscopy and density functional theory calculations. Our methodology provides a facile and adaptable route toward the isolation of a number of novel ferrocene and biferrocene derivatives. From our perspective, the asymmetric nature of these systems, along with the delicate and predictable redox control that these ligands exert on the central ferrocene unit(s), could lead to applications in molecular electronics, where these properties have previously shown promise in the fabrication of diodes and rectifiers, as well as in the synthesis of donor-π-acceptor systems.

Influence of terminally attached branched alkyloxy chains on the mesophase behaviour of calamitic liquid crystals

ABSTRACT Three sets of new rod-shaped liquid crystals with one terminal fixed branched alkyl chain, other terminal with varying normal alkyl chain, and central naphthalene with terminal branched chain derived symmetric molecules were synthesized and characterized. Chemical structures were confirmed by standard analytical methods. Liquid crystal properties were evaluated with the help of differential scanning calorimetry, polarized optical microscopy and X-ray studies. All the compounds favoured to exhibit highly birefringent smectic and nematic mesophase textures. Further, symmetric naphthalene derivatives preferably exhibited nematic mesophase with elevated transition temperatures.

Synthesis and Investigation of the Antibacterial Activity of New Tris-Thiourea Derivatives

An efficient procedure for the preparation of symmetrical tris-thiourea derivatives (5a – 5h) by means of one-pot condensation reaction between available benzoyl chlorides (1a –1h) with potassium thiocyanate (2) and melamine (4) under reflux conditions is presented. All the synthesized tris-thioureas were evaluated for their biological activities against a group of Gram-positive (Staphylococcus aureus and Bacillus cereus) and Gram-negative (Escherichia coli) bacteria. The synthesized compounds showed no activity against P. aeruginosa. All compounds exhibited excellent antibacterial activity against indicated bacterial strains. The new products were characterized using FT-IR, 1H and 13C NMR spectra, and elemental analysis.

Dual solvent-catalyst role of deep eutectic solvents in Hantzsch dihydropyridine synthesis

Deep eutectic solvents are a class of new generation green solvents formed from two or more components, which furnish a new homogeneous liquid phase with lower melting point than the individual components. Here, for the first time, dual role of DES as catalyst and reaction medium was studied for the synthesis of symmetric dihydropyridine derivatives from aldehyde, ethyl acetoacetate and ammonium acetate. The present article reports the suitability of six DESs for Hantzsch dihydropyridine synthesis at room temperature. Among this, DES 2 (ZrOCl2.8H2O and ethylene glycol at 1:2 ratio) was found to be the catalyst of choice with excellent recyclability. The role of DES in the present protocol was to activate the reactants through strong hydrogen bonding interaction and provide suitable medium for the reaction. The major advantages of DESs for the titled reaction are the easy preparation, low cost, non-volatility, biodegradability, simple catalytic process, excellent conversion and the reusability.

Synthesis of Acridinium Photocatalysts via Site-Selective C–H Alkylation

Acridinium dyes have been broadly used as photocatalysts, but it remains synthetically challenging to fine-tune their catalytic performance by functionalization of their structural cores. Acridiniu...

Obtaining symmetric and asymmetric bisphosphoramidates and bisphosphoramidothioates by a single step multicomponent reaction

We present a new single-step multicomponent reaction strategy for the synthesis of symmetric and (novel) asymmetric bisphosphoramidate and bisphosphoramidothioate derivatives. Reactions proceed under routine experimental conditions, do not require the aid of any catalyst, and provide moderate yields after a short time. We synthesized 18 different compounds, 10 of them for the first time. The cytotoxic activity of our adducts was assessed by measuring their inhibitory capacity (IC50) against two different cell lines, the A549 (lung cancer cells) and the SW1353 (chondrosarcoma cells).

Symmetrical Derivative of Anthrone as a Novel Receptor for Mercury Ions: Enhanced Performance of Modified Screen-Printed Electrode

Voltammetric sensor using a symmetrical derivative of anthrone3 (1,7-diamino-3,9-dibutyl benzo[1,2,3-de:4,5,6-d’e’]diquinoline-2,8(3H,9H)-dione) (SPE-A) has been developed as a probe for Hg(II) ions. Performance of the probe as screen-printed electrode modified with the receptor (SPE-A) has been compared with anthrone3 in solution phase, using 1:1 water-acetonitrile solvent system. Anthrone3 displayed an electrochemically quasi-reversible nature in voltammograms with both the systems and is presented as a novel disposable voltammetric sensor for mercury ions. Upon interaction with cations, both the electrode systems showed sensitivity towards Hg2+ ions with a lower detection limit of 0.61 µM. The magnitude of the voltammetric current with the SPE-A exhibited three times the current obtained with a bare glassy carbon electrode (GC). Kinetic performance of the SPE-A electrode is better than the GC electrode. The morphological studies indicate reusability of the electrodes.

Characterizing Peano and Symmetric Derivatives and the GGR Conjecture’s Solution

Abstract We provide three characterizations of the $n$th symmetric (Peano) derivative $f_{(n)}^{s}(x)$ in terms of symmetric generalized Riemann derivatives of a function $f$ at $x$ and a characterization of the $n$th Peano derivative $f_{(n)}(x)$ in terms of generalized Riemann derivatives of $f$ at $x$. The latter has been a conjecture by Ginchev, Guerragio, and Rocca since 1998.

A series of asymmetric and symmetric porphyrin derivatives: one-pot synthesis, nonlinear optical and optical limiting properties

In this work, a series of asymmetric and symmetric porphyrin derivatives (structure types: A4, A3B1, trans-A2B2, cis-A2B2, A1B3, and B4) have been synthesized via a one-pot method and characterized to identify their structures and properties.

Spacer group-controlled luminescence and response of C3-symmetric triphenylamine derivatives towards force stimuli

Spacer groups have the ability to regulate the responses of two C3-symmetric triphenylamine derivatives. Double bonds induced larger spectral shifts compared to that of single bonds.

Symmetrical and unsymmetrical thiazole-based ESIPT derivatives: the highly selective fluorescence sensing of Cu2+ and structure-controlled reversible mechanofluorochromism

Excited state intramolecular proton transfer (ESIPT) process-based organic fluorophores provide an opportunity to develop large Stokes-shifted multifunctional fluorescence systems for light emitting, chemosensing and bioimaging applications.