Study of sulfur adlayers on Au(1 1 1) from basic hydrolysis of piperazine bis(dithiocarbamate) sodium salt

Martínez, Jorge Hernández; Valenzuela, Juliana González; Hernandez-Tamargo, Carlos E.; Cao‐Milán, Roberto; Herrera, J.; Dı́az, José A.; Farı́as, M.H.; Mikosch, Hans; Hernández-Hernández, Miguel A.

doi:10.1016/j.apsusc.2015.03.163

Cited by 8 publications

(11 citation statements)

References 51 publications

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“…Finally, the estimated S/Au signal ratio results in a total S coverage ∼0.32, i.e., the corresponding coverage results θ Smon ∼ 0.18, θ Spoly ∼ 0.11, θ Sfree ∼ 0.03. In a previous work 14 it has been considered that the bright square-shaped patterns correspond to polysulfides adsorbed on a first layer of diluted monomeric sulfur. However, the proportion of free sulfur species (S not bonded to the Au substrate) in the XPS spectra (Figure 3a, green component) is too small compared to the total amount of sulfur present on the surface.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Role of Gold Adatoms in the Adsorption of Sulfide Species on the Gold(001)-hex Surface

et al. 2018

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We have studied the adsorption of reduced sulfur species on the Au(001)-hex surface from diluted ethanolic sulfide solutions by STM, XPS, electrochemical techniques and DFT calculations. Our results reveal the absence of S multilayers because all S species are bonded to Au surface atoms. Monomeric S adsorbs at hollow sites forming a (2×2) lattice, while S 2 species either capture the gold adatoms (Au ad) that result from the hex lifting or remove Au ad from the substrate forming well-ordered S 8-like structures. These are formed by four S 2 species coordinated by a central Au ad , with AuSS interatomic distances closely resembling those of a metal disulfide. Our results explain not only the predominant surface structures on the gold surface but also topographic features, like Au ad islands and Au vacancy islands, and also the chemical nature of adsorbed species from XPS S 2p spectra. In contrast to the S heads of small aromatic thiols, which exhibit a low affinity for Au ad , strongly reactive sulfide species react with the metal adatoms leading to well-ordered complexes.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Role of Gold Adatoms in the Adsorption of Sulfide Species on the Gold(001)-hex Surface

et al. 2018

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“…The spectrum (Figure b) was curve-fitted by a set of two doublets with 2p3/2 binding energies at 160.4 and 162.8 eV. The first doublet was corresponding to monatomic sulfur adsorbed on the Au NPs surface, while the second doublet was attributed to the presence of polymeric sulfur species . The spectrum of S 2p did not show any other components in the 163–164 eV energy range, where sulfur multilayer commonly appeared .…”

Section: Resultsmentioning

confidence: 99%

“…The first doublet was corresponding to monatomic sulfur adsorbed on the Au NPs surface, while the second doublet was attributed to the presence of polymeric sulfur species. 35 The spectrum of S 2p did not show any other components in the 163−164 eV energy range, where sulfur multilayer commonly appeared. 37 This covalent interaction between thiol group in QCS-SH and Au NPs could also be determined by Raman spectroscopy (Figure S4).…”

Section: Acs Biomaterials Science and Engineeringmentioning

confidence: 89%

“…The analysis of the Au 4f and S 2p spectra showed a very broad signal, similar to that previously reported adsorption of sulfur on gold. 35,36 Thereinto, two main peaks were observed for the Au 4f signal (Figure 2a). The first peak located at ∼84.0 eV was corresponding to Au 4f 7/2 , and a second doublet for Au 4f 5/2 component was also observed at ∼87.6 eV, which indicated the existence of the Au− S bond in the surface of Au NPs.…”

Section: Acs Biomaterials Science and Engineeringmentioning

confidence: 96%

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Porphyrin Derivative Conjugated with Gold Nanoparticles for Dual-Modality Photodynamic and Photothermal Therapies In Vitro

Zeng

Yang

Shi

et al. 2018

ACS Biomater. Sci. Eng.

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Gold nanoparticles (Au NPs) have been confirmed to show excellent photothermal conversion property for tumor theranostic applications. To improve the antitumor efficacy, a novel nanoplatform system composed of porphyrin derivative and Au NPs was fabricated to study the dual-modality photodynamic and photothermal therapy with laser irradiation. Modified chitosan was coated on the Au NPs surface via ligand exchange between thiol groups and Au. The chitosan-coated Au NPs (QCS-SH/Au NPs) were further conjugated with meso-tetrakis(4-sulphonatophenyl)porphyrin (TPPS) via electrostatic interaction to obtain the porphyrin-conjugated Au hybrid nanoparticles (TPPS/QCS-SH/Au NPs). Size, morphology, and properties of the prepared nanoparticles were confirmed by Zeta potential, nanoparticle size analyzer, transmission electron microscopy (TEM), and UV–vis spectroscopy. Moreover, both photothermal therapy (PTT) and photodynamic therapy (PDT) were investigated. Compared with alone Au NPs or TPPS, the hybrid TPPS/QCS-SH/Au NPs with lower cytotoxicity showed durable elevated temperature to around 56 °C and large amount of singlet oxygen (1O2) produced from TPPS. Thus, the hybrid nanoparticles showed a more significant synergistic therapy effect of hyperthermia from PTT as well as 1O2 from PDT, which has potential applications in the tumor therapy fields.

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“…A standard method was used in the synthesis of dithiocarbamte compounds [13], it was used with a slight modifications to prepare the free ligand Sodium 2-(3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl)methyl)sulfinyl)-1H-benzoimidazole-1-carbodithioate (NaL). Mixed equimolar amounts from reactors in following; (1 g, 2.70mmol) of (RS)-2-([3-methyl-4-(2,2,2-trifluoroethoxy)pyridin-2-yl] methylsulfinyl)-1H benzoimidazole was dissolved in 20ml of absolute methanol in a round bottom flask, then was added (0.10g, 2.70mmol) of sodium hydroxide dissolved in 2ml of double distilled water.…”

Section: Synthesis Of Free Ligandmentioning

confidence: 99%

Synthesis, Characterization and Biological Evaluation of New Dithiocarbamate Ligand and Its Complexes with some Metal Ions

Numan¹,

Ibraheem²,

Ibrahim³

2017

IHJPAS

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New bidentate dithiocarbamate ligand (NaL) namely . To characterize the ligand and its complexes, used different analyses methods such FTIR, UV-Vis, elemental microanalysis, atomic absoreption, magnetic susceptibility, conductance, melting points, 1 H-13 C-NMR spectroscopy, thermal analysis and mass spectrum. These studies indicated the formation of DTC complexes which their geometries about metal centers are octahedral; except Pd-complex is square planer. The bacterial activity evaluation against investigated bacterial species indicated that the metal complexes are more active than the free ligand when compared them.

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Study of sulfur adlayers on Au(1 1 1) from basic hydrolysis of piperazine bis(dithiocarbamate) sodium salt

Cited by 8 publications

References 51 publications

Role of Gold Adatoms in the Adsorption of Sulfide Species on the Gold(001)-hex Surface

Role of Gold Adatoms in the Adsorption of Sulfide Species on the Gold(001)-hex Surface

Porphyrin Derivative Conjugated with Gold Nanoparticles for Dual-Modality Photodynamic and Photothermal Therapies In Vitro

Synthesis, Characterization and Biological Evaluation of New Dithiocarbamate Ligand and Its Complexes with some Metal Ions

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