Synthesis Of Thiol Research Articles

Synthesis of Thiol Functionalized MOF-808 and its Efficiency for Mercury Removal.

A thiol-functionalized MOF-808 was produced and used to remove mercury by post-synthetic modification using 6-mercaponicotinic acid (6mna). Parent MOF-808 was impregnated for varied periods of time in the 6mna solution to create modified MOF-808 materials, known as MOF-808-6mna-x, where x refers to the impregnation time. Diffraction and several spectroscopic techniques were employed to quantify and confirm the coordination of 6mna into MOF-808 framework. The amount of grafted 6man and the ability for adsorption of mercury (Hg) were shown to be linearly associated; the functionalized MOF-808-6mna-36 demonstrated improved Hg(II) removal, with an adsorption capacity of 250 mg/g.

Synthesis and structural characterization of picolinamide and thiol chelated Pt(II) complexes: Their kinetics & mechanism and theoretical approach

Picolinamide is a versatile chelating ligand and it reveals peculiar behaviour for metal chelation, particularly for its amide group. The bonding mode of N & O donor centres of an amide group depends on the metal ion, their associated charge and the other associated ligands in metal complexes. Picolinamide (pica) based Pt(II) complex C1 to C4 were synthesized and their bonding mode with Pt(II) was established by different spectroscopic analyses and theoretical approaches for their structural importance and potential anticancer activity. The complex [Pt(pica)Cl2]; C1 was synthesized and its hydrolyzed product [Pt(pica)(OH2)2](ClO4)2; C2 was obtained from hydrolysis of complex C1. The kinetic and mechanistic study for the interaction of complex C2 with l-cysteine (l-cys) and N-acetyl-l-cysteine (N-ac-l-cys) was performed in pseudo-first-order reaction condition to evaluate the rate constants, rate equation, enthalpy of activation (ΔHǂ) and entropy of activation (ΔSǂ). Sulfur chelated complex [Pt(pica)(l-cys)]+; C3 and [Pt(pica)(N-ac-l-cys)]; C4 were obtained when a 1:1 M ratio of C2 and thiol are mixed separately. Theoretical investigation on drug likeness property was evaluated by PASS prediction software. The theoretical approach on structural properties like; structural optimization, HOMO-LUMO energy, TD-DFT simulation, MEP and reactivity descriptors of the complexes were executed and analyzed with the Gaussian09 software package. Molecular docking of the complexes was executed with DNA and BSA.

Synthesis of peripheral thiol functionalized (NiII) phthalocyanine and its attachment on Au electrode for electrochemical determination of L-DOPA

This paper presents the synthesis, characterization, and electrocatalytic behavior of peripheral thiol-functionalized nickel(II) phthalocyanine (4β-NiIITTPc). The complex was synthesized and characterized using MALDI-TOF mass spectra, UV–visible, and FT-IR spectroscopies. Upon self-assembly on the Au surface from dimethylformamide solution, 4β-NiIITTPc forms via the formation of an Au-S bond. The attachment onto the Au surface was verified through Raman spectroscopy and cyclic voltammetry, with characteristic bands at 2572 and 250 cm−1 corresponding to -SH and Au-S stretching vibrations, respectively. Notably, the -SH stretching indicates that not all four -SH groups of 4β-NiIITTPc are involved in chemisorption. The resulting self-assembled film on the Au electrode exhibits well-defined oxidation peaks at +0.34 V and +0.56 V, corresponding to NiIII/NiII and NiIIPc−1/NiIIPc−2, respectively. The surface coverage was estimated from the charge associated with NiII/NiIII oxidation, yielding 1.01 × 10−10 mol cm−2. Finally, the electrocatalytic activity of the self-assembled monolayer (SAM) of 4β-NiIITTPc on Au electrodes was assessed by studying the oxidation of 3,4-dihydroxy-1-phenylalanine (L-dopa) as a probe. The SAM-modified electrode not only shifts the oxidation potential of L-dopa to a less positive potential but also enhances the oxidation current and mitigates electrode surface fouling compared to the bare Au electrode.

Synthesis and Crystallization of Waterborne Thiol-ene Polymers: Toward Innovative Oxygen Barrier Coatings.

The synthesis of waterborne thiol-ene polymer dispersions is challenging due to the high reactivity of thiol monomers and the premature thiol-ene polymerization that leads to high irreproducibility. By turning this challenge into an advantage, a synthesis approach of high solid content film-forming waterborne poly(thioether) prepolymers is reported based on initiator-free step growth sonopolymerization. Copolymerization of bifunctional thiol and ene monomers diallyl terephthalate, glycol dimercaptoacetate, glycol dimercaptopropionate, and 2,2-(ethylenedioxy)diethanethiol gave rise to linear poly(thioether) functional chains with molar mass ranging between 7 and 23 kDa when synthesized at 30% solid content and between 1 and 9 kDa at increased solid content of 50%. To further increase the polymers' molar mass, an additional photopolymerization step was performed in the presence of a water-soluble photoinitiator, i.e., lithium phenyl-2,4,6-trimethylbenzoylphosphinate, leading to high molar mass chains of up to 200 kDa, the highest reported so far for step grown poly(thioethers). The polymer dispersions presented good film-forming ability at room temperature, yielding semicrystalline films with a high potential for barrier coating applications. Nevertheless, affected by the polymer chemical repeating structure, which includes an aromatic ring, these thiol-ene chains can only crystallize very slowly from the molten state. Herein, for the first time, we present the successful implementation of a self-nucleation (SN) procedure for these types of poly(thioethers), which effectively accelerates their crystallization kinetics.

Novel [18F]-labeled thiol for the labeling of Dha- or maleimide-containing biomolecules

BackgroundProsthetic approach for the radiolabeling of biologics with fluorine-18 is a robust strategy and has been employed for many years. It requires fast, biocompatible and selective reactions suited to these fragile molecules. Michael addition of a nucleophilic thiol moiety on α,β-unsaturated carbonyl entities is an interesting compromise between simplicity of preparation of the prosthetic reagent and control of the selectivity of the addition. The α,β-unsaturated carbonyl entity of the biologic can easily be generated by addition of a maleimide function using adequate heterobifunctional linkers or generated by selective modification of a cysteine residue leading to a dehydroalanine moiety. We report here the design, synthesis and radiosynthesis of a new fluoropyridine-based thiol [18F]FPySH and its conjugation via Michael addition on model dehydroalanine- or maleimide-containing biologics.ResultsThe preparation of cold reference and labeling precursor of [18F]FPySH was achieved and its radiosynthesis was fully automated, enabling production of the thiol prosthetic group with a 7 ± 2.1% radiochemical yield after two steps. The conjugation of [18F]FPySH to two model Dha-containing molecules was then carried out in reducing conditions, yielding the corresponding adducts in 30–45 min reaction time. Furthermore, [18F]FPySH was employed to radiolabel the maleimide-modified c(RGDfK) peptide, affording the radiofluorinated analogue in 15 min.ConclusionWe have developed an original [18F]-labeled thiol for site-selective conjugation and radiolabeling of Dha or maleimide-containing biomolecules of interest. Labeling of three model compounds was successfully carried out and gave the expected radiofluorinated adducts in less than 45 min, thus compatible with fluorine-18 half-life.

Functional Alkyl‐Ferrocene Grafted Hydroxyl Terminated Polybutadiene

AbstractGrafting of functional ferrocene molecules in the backbone of hydroxyl terminated polybutadiene (HTPB) without altering physical characteristics such as viscosity, hydroxyl value, molecular weight of the pristine HTPB remains as an important challenge owing to the difficulty in synthesizing appropriate functional ferrocene molecules and the suitable grafting methodology. The present report describes a facile and cost‐effective process for the synthesis of thiol, silyl and halogen derivatives of alkyl‐ferrocene. This process delineates the use of cyclic anhydrides as precursor for functionalizing ferrocene with terminal carboxylic acid in order to purify via acid‐base workup. The synthetic process includes moderate reaction conditions with good to excellent yields. The ferrocene‐alkyl‐silane and ferrocene‐alkyl‐thiol are grafted covalently to the pendent vinylic groups of HTPB with unaltered physical characteristic in order to prepare polymeric binders with enhanced burn rate for the use in composite solid propellant for aerospace applications.

Synthesis and characterization of thiol modified beta cyclodextrin, its biocompatible analysis and application as a modified release carrier of ticagrelor

Thiol modification of beta cyclodextrin (β-CD) was carried out using thiourea, which served as a thiol donor. The chemical reaction was mediated using HCl. Polymer prepared via thiolation was further subjected to physicochemical and biocompatible analysis. Acute oral toxicity and compatibility was determined in albino rats. Furthermore, compressed tablets of ticagrelor (TCG) were prepared using modified and unmodified polymers and evaluated via various quality control tests. Thiolation was successfully achieved and confirmed by the FTIR scan, as a significant corresponding peak was observed at 2692 cm−1 wavenumber, demonstrating the attachment of –SH group. In vivo analysis has confirmed the safe use of β-CD, as none of the vital organs showed any kind of toxic effects. Dissolution studies revealed that Tβ-CD was able to release 96.62% of the drug within 1 h of the study, hence providing an immediate release. Conclusively, a thiol moiety was successfully attached to the polymeric backbone and was found safe to be used as a pharmaceutical excipient.

Synthesis of Thiol modified magMCM-41 nanoparticles with rice husk ash as a robust, high effective, and recycling magnetic sorbent for the removal of herbicides

The presence of agricultural herbicides in the aquatic environment is one of the most important problems of water resource ecosystems. The present study was performed to remove 2,4-Dichlorophenoxyacetic acid and glyphosate herbicides from aqueous solutions by Thiol modified the magnetic mesoporous silica (magMCM-41) nanoparticles using extracted silica from rice husk ash, and the modification was performed by the 3-Mercaptopropyltrimethoxysilane (Thiol) functional group. The properties of the synthesized nanoparticles were investigated using XRD, FT-IR, TGA, VSM, pHZPC and TEM analyzes. The efficiency of the synthesized adsorbent was also studied by investigating the effect of pH, time, adsorbent dose, and initial concentrations of contaminants. The results of this study showed that the highest rate of elimination of 2,4-Dichlorophenoxyacetic acid and glyphosate was observed at herbicides the concentrations of 20 mg L−1, adsorbent dose of 0.2 gL−1, the contact time of 30 and 60 min and pH of 6 and 5 respectively. Under optimum conditions, 83.44 % and 79.38 % were removed for 2,4-Dichlorophenoxyacetic acid and glyphosate, respectively. Also, the adsorption capacity of SH-mgMCM-41 for 2,4-Dichlorophenoxyacetic acid and glyphosate is 120.36 and 108.53 mg/g, respectively. The results of the adsorption isotherms showed that the Langmuir model had a little better fit for 2,4-Dichlorophenoxyacetic acid and glyphosate with a correlation coefficient of 0.99 and 0.98, respectively. The thermodynamic results showed that the adsorption process is endothermic and spontaneous. After 5 consecutive adsorption-resorption cycles for 2,4-Dichlorophenoxyacetic acid and glyphosate, the removal efficiency was 72 % and 65 %, respectively. SH-magMCM-41 nano-adsorbent can be an effective adsorbent for the removal of 2,4-Dichlorophenoxyacetic acid and glyphosate herbicides.

Different strategies for lead detoxification in dwarf bamboo tissues.

Dwarf bamboo Sasa argenteostriata (Regel) E.G. Camus is considered as potential plants for metal phytoremediation in previous filed observations. However, the mechanisms of lead (Pb) detoxification has not been described. The objective of this study was to explore the difference strategies or mechanisms of Pb detoxification in plant tissues. In this regard, four Pb treatments with hydroponics including 0 (control), 300, 600, and 900mgL-1 were conducted to examine subcellular compartmentalization, Pb accumulation/species and antioxidant-assisted chelation. Our findings showed the retention of Pb by the whip-root system is one of its detoxification mechanisms to avoid damage the shoots. In addition, the cell wall retention is the dominant detoxification strategy of whips, new roots, old roots and new/old stems, while vacuolar compartmentalization is for new/old leaves. Interestingly, four low-mobility/-toxicity Pb species (i.e., FNaCl, FHAc, FHCl and FR) are distributed in roots, whips and stems, while two high-mobility/-toxicity Pb species (FE and FW) in leaves. The conversion of Pb to low-toxicity/-migration is a Pb-detoxification strategy in roots, whips and stems but not in leaves. Besides, the new/old roots and leaves can alleviate Pb damage through the synthesis of non-protein thiol, glutathione and phytochelatins. Among these, phytochelatins play a leading role in the detoxification in new/old roots, while glutathione is in new/old leaves. This study provides the first comprehensive evidence regarding the different strategies for Pb detoxification in dwarf bamboo tissues from physiological to cellular level, supporting that this plant could be rehabilitated for phytoremediation in Pb-contaminated media.

Synthesis and properties of amino and thiol functionalized graphene oxide

Graphite, an allotrope of carbon, has been extensively researched in varied fields of science due to its typical structure and properties. Many researchers have transformed graphene from graphite in many ways. Functionalized graphene have immense importance because of advancement of properties for technological applications. =N– and –S– fabricated graphene oxide composite was prepared. The amino and thiol functionalized graphene oxide with improved properties is expected to adsorb heavy and toxic metals like Pb, Cd, Hg, and Ag from aqueous solutions. The synthesized composite was confirmed and characterized by various characterization techniques like FTIR, SEM, TEM and XRD.

Regioselective thiocyanation of corroles and the synthesis of gold nanoparticle-corrole assemblies.

Herein we demonstrate a synthetic protocol for the regioselective thiocyanation of corroles. To the best of our knowledge, thiocyanato appended corrole has never been reported earlier. The resulting thiocyanato appended corrole turned out to be a good corrole based precursor for the facile synthesis of thiol protected gold nanoparticles (Au NPs). The ligand system acts as a good bidentate framework and passivates the gold surface. A strong electronic interaction between the corrole and the gold nanoparticles is manifested by their unique photo physical properties and it also confirms that the binding through β-substitutions has a more pronounced effect even though the corrole rings are face-off to the gold surface.

Design and development of thiolated graphene oxide nanosheets for brain tumor targeting

The present investigation emphasizes on synthesis and characterization of thiol functionalized reduced graphene oxide (TrGO) as a novel platform for loading of anticancer drug methotrexate (TrGO-MTX), through amide bonding. Thiolation of graphene oxide (GO) was achieved by transesterification process. The introduction of sulfur containing chemical groups and the partial reduction of GO to TrGO were proven by analytical techniques. Thiol content was found to be 6.98 mM by Ellman’s method in a quantitative manner. Furthermore, antineoplastic action of TrGO-MTX against human glioblastoma astrocytom U-373 MG cell line was studied, wherein TrGO-MTX demonstrated significant inhibition rate as compared with pure MTX.

One pot synthesis of stable water soluble thiol capped CdTe nanoparticles: Effect of precursor ratio, refluxing time and capping group on the optical property

Highly crystalline, monodispersed and stable water soluble thiol capped cadmium telluride nanoparticles (CdTe NPs) were synthesized via an environmental friendly, simple one-pot method in the absence of an inert atmosphere at constant pH. The effect of varying the precursor ratio and capping agent while keeping all other parameters constant, on the optical and structural properties of the as-synthesized nanocrystals was investigated. The optical and structural properties of the as-synthesized CdTe NPs was explored by using UV–visible (UV–Vis) absorption and photoluminescence (PL) spectroscopy, Fourier transform infra-red spectroscopy (FTIR) and transmission electron microscopy (TEM). Optical analysis shows that all the as-synthesized CdTe NPs possesses good optical properties with 1:0.8 ratio showing the highest absorbance and emission wavelength at different reaction time. The thiol capped water soluble CdTe NPs were optically stable at ambient conditions for several months.

基于巯基功能化聚(3,4-乙撑二氧噻吩)/Au纳米复合材料的合成及其在葡萄糖检测中的应用

基于巯基功能化聚(3,4-乙撑二氧噻吩)/Au纳米复合材料的合成及其在葡萄糖检测中的应用

Synthesis and properties of multifunctional thiol crosslinked gels containing disulfide bond in the network structure

ABSTRACTJoint crosslinked gels containing disulfide linkage have been synthesized by oxidation reaction of multi‐functional thiol monomers, trimethylolpropane tris(3‐mercaptopropionate), tris‐[3‐mercaptopropionyloxy‐ethyl]‐isocyanurate, pentaerythritol tetrakis (3‐mercaptopropionate), and dipenta‐erythritol hexakis (3‐mercaptopropionate) in dimethyl sulfoxide (DMSO). Both the oxidation reactions with DMSO at 85 °C and Albright‐Goldman oxidation in the presence of acetic anhydride at 50 °C yielded the corresponding gels. The oxidation reaction with DMSO showed higher reaction conversion than that with Albright‐Goldman oxidation. Network structure of the gels was quantitatively characterized by means of a scanning microscopic light scattering. The reactions formed homogeneous network structure with about 0.5 nm of mesh in the gels. Mechanical properties of the obtained gels were investigated by compression test. Increasing of the crosslinking density with increasing of the monomer concentration, number of thiol group of the monomer or reaction conversion, raised Young's modulus, and breaking stress of the gels. Cogelation of the tri‐, tetra‐, of hexa‐thiol monomer and dithiol monomers yielded soft and flexible gels. Reduction of the disulfide bonds in the gels by dithiothreitol turned the gel into solution. Heating of the resulting solution induced the regelation by reforming of the disulfide bonds. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3749–3756

High-performance waterborne UV-curable polyurethane dispersion based on thiol–acrylate/thiol–epoxy hybrid networks

Synthesis, characterization, and film performance of waterborne thiol–acrylate/thiol–epoxy hybrid coatings are highlighted in this article. A dimer acid-modified epoxy (DME) polyol, containing both hydroxyl and epoxy functional groups, was prepared by reacting epoxy resin (EEW = 190 g/equi) with dimer fatty acid at 2:1 molar ratio. Further, a base UV-curable polyurethane acrylate dispersion (UV-PUD), with a pendant epoxy functional group, was prepared by reacting polyol (DME), isophorone diisocyanate, and dimethylol propionic acid and end-capped with hydroxyethyl methacrylate with subsequent dispersion in water. Prepared intermediates were characterized for the parameters relevant to the study by physical, spectroscopic, and chemical methods. UV-curable thiol–acrylate/thiol–epoxy hybrid coatings were prepared by blending UV-PUD with trimethylolpropane tris(3-mercaptopropionate) (TMPMP) at four different thiol ratios (0, 0.3, 0.6, and 1.0) with respect to acrylate/epoxy groups. Cured films of the hybrid coating were identified by FTIR spectroscopy. The impact of thiol ratio on film performance was evaluated in terms of mechanical, chemical, thermal, and coating properties. The gel content measurements confirm that the addition of TMPMP increased the double bond conversion along with the epoxy group. Evaluation of cured samples shows the significant improvement in storage modulus, glass transition temperature, tensile strength, and hardness with increase in thiol ratio. The cured films possessed excellent water and acid resistance (<4%) even after 28 days of immersion. Moreover, the notable improvement was alkali resistance of cured films, i.e., as thiol ratio was increased from 0 to 1, weight loss in alkaline environment deceased from 49.5 to 4.5% after 28 days. Better properties of the thiol–acrylate/thiol–epoxy hybrid films will allow it as a potential application in low-volatile high-performance coatings.

The significance of bromide in the Brust-Schiffrin synthesis of thiol protected gold nanoparticles.

The mechanism of the two-phase Brust-Schiffrin synthesis of alkane thiol protected metal nanoparticles is known to be highly sensitive to the precursor species and reactant conditions. In this work X-ray absorption spectroscopy is used in conjunction with liquid/liquid electrochemistry to highlight the significance of Br- in the reaction mechanism. The species [AuBr4]- is shown to be a preferable precursor in the Brust-Schiffrin method as it is more resistant to the formation of Au(i) thiolate species than [AuCl4]-. Previous literature has demonstrated that avoidance of the Au(i) thiolate is critical to achieving a good yield of nanoparticles, as [Au(i)X2]- species are more readily reduced by NaBH4. We propose that the observed behavior of [AuBr4]- species described herein explains the discrepancies in reported behavior present in the literature to date. This new mechanistic understanding should enable nanoparticle synthesis with a higher yield and reduce particle size polydispersity.

New alternative to liquid thiokol in commercial sealants

The main types of polysulfide oligomers are described. The strong and weak points of liquid thiokols are considered. The synthesis of polyester urethane thiol (AR polymer) is described. AR polymer sealants are shown to have several advantages compared with thiokol sealants. The main developments by OOO Polymix Kazan in the area of synthesized new types of thiol oligomers and derived sealants are presented.

Synthesis and Characterization of Thiol- and Carboxyl-Functionalized Mesoporous Silica Nanoparticles

The purpose of this article is to synthesize the thiol-and carboxyl-bifunctionalized mesoporous silica nanoparticles (CMS-SH-COOH). CMS-SH-COOH was successfully synthesized by co-condensation and post-grafting methods. Moreover, the particle size and structural properties of CMS-SH-COOH were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The obtained results indicated that the CMS-SH-COOH presented a uniform spherical shape with a wormhole arrangement of the mesopores and a relatively narrow paticle distribition. Therefore, the CMS-SH-COOH might be a great potential carrier for the drug delivery system in the future.

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

The synthesis and physical properties of thiol–ene elastomers derived from plant-based phenolic acids were explored. Phenolic acids of varying functionality (ranging from 2 to 4 hydroxyl and carboxyl groups per molecule) and relative placement of functional groups (ortho, meta, para) were allylated and subsequently reacted with a multifunctional thiol using a photoinitiator. The thermal and mechanical behaviors of the resulting elastomers were characterized. The networks derived from difunctional allylated phenolic acids exhibited narrow glass transitions (indicating a high degree of network homogeneity) and glass transition temperatures (Tg) which correlated with their cross-link density. The para placement of allyl groups on the allylated phenolic acid produced a network with the highest cross-link density, Tg, modulus, tensile strength, and elongation at break (followed by ortho and then meta). As the functionality of the allylated monomer increased (to 3–4 allyl groups per molecule), the cross-link de...