Detaching Thiolates from Copper and Gold Clusters:  Which Bonds to Break?

Konôpka, Martin; Rousseau, Roger; Štich, Ivan; Marx, Dominik

doi:10.1021/ja047946j

Cited by 80 publications

(97 citation statements)

References 61 publications

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“…For the reduced gold surface, the force histogram indicates a most probable rupture force of 0.62±0.18 nN. Previous studies 5,27,[30][31][32]34,43,44 strongly indicated that the breakage takes place at the Au-Au bond around the Au-S binding sites, which was the weakest among the covalent bonds (that is, Si-O, Si-C, C-N, C-C, C-O, Au-S and Au-Au) in the linkage, leaving one or more gold atoms at the terminal of the tethered linker. Control experiments, in which the thiolterminated PEG was replaced with sulphur-free methoxylterminated PEG, were performed to confirm that the rupture force obtained above originated from the interaction between the sulphydryl group and gold surfaces.…”

Section: Resultsmentioning

confidence: 76%

Quantifying thiol–gold interactions towards the efficient strength control

et al. 2014

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The strength of the thiol-gold interactions provides the basis to fabricate robust self-assembled monolayers for diverse applications. Investigation on the stability of thiol-gold interactions has thus become a hot topic. Here we use atomic force microscopy to quantify the stability of individual thiol-gold contacts formed both by isolated single thiols and in self-assembled monolayers on gold surface. Our results show that the oxidized gold surface can enhance greatly the stability of gold-thiol contacts. In addition, the shift of binding modes from a coordinate bond to a covalent bond with the change in environmental pH and interaction time has been observed experimentally. Furthermore, isolated thiol-gold contact is found to be more stable than that in self-assembled monolayers. Our findings revealed mechanisms to control the strength of thiol-gold contacts and will help guide the design of thiol-gold contacts for a variety of practical applications.

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Section: Resultsmentioning

confidence: 76%

Quantifying thiol–gold interactions towards the efficient strength control

et al. 2014

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“…In chemical compounds and in molecular materials, Au(I)-thiolate species are well established (1)(2)(3)(4)(5). Bond polarizations can be both measured (27)(28)(29)(30)(31)(32)(33)(34)(35)(36) and calculated (19,29,31,32,(37)(38)(39)(40)(41)(42)(43), leading to the conclusion that the charge on S is of order −0.2 e (1-3). Although such quantities cannot be uniquely defined by either experimental measurement or computational evaluation, the broad range of methods that have been applied yield a recognizable consensus.…”

Section: Bond Polarization Data Indicates That Only Structures 1b Andmentioning

confidence: 99%

Gold surfaces and nanoparticles are protected by Au(0)–thiyl species and are destroyed when Au(I)–thiolates form

Reimers

Ford

Halder

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

126

163

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The synthetic chemistry and spectroscopy of sulfur-protected gold surfaces and nanoparticles is analyzed, indicating that the electronic structure of the interface is Au(0)-thiyl, with Au(I)-thiolates identified as high-energy excited surface states. Density-functional theory indicates that it is the noble character of gold and nanoparticle surfaces that destabilizes Au(I)-thiolates. Bonding results from large van der Waals forces, influenced by covalent bonding induced through s-d hybridization and charge polarization effects that perturbatively mix in some Au(I)-thiolate character. A simple method for quantifying these contributions is presented, revealing that a driving force for nanoparticle growth is nobleization, minimizing Au(I)-thiolate involvement. Predictions that Brust-Schiffrin reactions involve thiolate anion intermediates are verified spectroscopically, establishing a key feature needed to understand nanoparticle growth. Mixing of preprepared Au(I) and thiolate reactants always produces Au(I)-thiolate thin films or compounds rather than monolayers. Smooth links to O, Se, Te, C, and N linker chemistry are established.gold-sulfur bonding | synthesis | mechanism | electronic structure | nanoparticle G old self-assembled monolayers (SAMs) and monolayerprotected gold nanoparticles form important classes of systems relevant for modern nanotechnological and sensing applications (1-5). Understanding the chemical nature of these interfaces is critical to the design of new synthesis techniques, the design of new spectroscopic methods to investigate them, and to developing system properties or device applications. Over the last 10 y, great progress has been made in understanding the atomic structures of gold-sulfur interfaces (6). Most discussion (7) has focused on the identification of adatom-bound motifs of the form RS-Au-SR (where R is typically a linear alkyl chain or phenyl group) sitting above a regular Au(111) surface (8-10) or on top of a nanoparticle core of regular geometry (11), Other variant structures have also been either observed, such as polymeric chains such as the trimer RS-Au-SR-Au-SR) (10, 11), or proposed (8,12,13). By considering the four isomers of butanethiol (14), we have shown that alternative structures can also be produced in which RS groups bind directly to an Au(111) surface without gold adatoms. This occurs whenever steric interactions across the adatoms are too strong or steric intermolecular packing forces allow for very high surface coverages if both adatom and directly bound motifs coexist in the same regular SAM (15). The cross-adatom steric effect has also been demonstrated for gold nanoparticles (16), and we have shown that Coulombic interactions between charged tail groups can also inhibit adatom formation (17). SAMs involving adatoms have poor longrange order owing to the surface pitting that is required to deliver gold adatoms, while directly bound motifs lead to regular surfaces (18).There is clearly a delicate balance between the forces that direct these different in...

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“…[3] As such, there has been an intense effort on the part of the atomistic-simulations community to model the structures, energetics and spectroscopic properties of these materials. [4][5][6][7][8][9][10][11][12] However, there is still much debate in the literature regarding the nature of the thiolatemetal interaction [13] as well as the nature of the adsorption sites of the thiols [14,15] and possible low-temperature superstructures.[16] With the notable exception of ref.[17], where ab initio molecular dynamics (AIMD) simulations have been performed to model the pulling of a single thiolate from a Au surface, there has been little attention paid to the role of finitetemperature effects in these materials by the ab initio electronic-structure community. This is despite the fact that gold is known to be a very dynamical element that exhibits exceptional diffusivity and mobility.…”

mentioning

confidence: 99%

An Effective Pseudopotential for Modeling Gold Surface Slabs for Ab Initio Simulations

Rousseau¹,

Mazzarello²,

Scandolo³

2005

ChemPhysChem

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Dedicated to Professor Michele Parrinello on the occasion of his 60th birthday.Self-assembled monolayers (SAMs) of sulfur-containing organic molecules on bulk gold surfaces are among some of the currently most-studied molecule/metal interfaces, with potential applications ranging from nanolithography [1] and molecular electronics [2] to biosensors. [3] As such, there has been an intense effort on the part of the atomistic-simulations community to model the structures, energetics and spectroscopic properties of these materials. [4][5][6][7][8][9][10][11][12] However, there is still much debate in the literature regarding the nature of the thiolatemetal interaction [13] as well as the nature of the adsorption sites of the thiols [14,15] and possible low-temperature superstructures.[16] With the notable exception of ref.[17], where ab initio molecular dynamics (AIMD) simulations have been performed to model the pulling of a single thiolate from a Au surface, there has been little attention paid to the role of finitetemperature effects in these materials by the ab initio electronic-structure community. This is despite the fact that gold is known to be a very dynamical element that exhibits exceptional diffusivity and mobility. Though it is possible to model the dynamical behavior of Au via effective interatomic potentials, [18] there currently is no reliable interatomic potential to model the molecule-metal interaction. In principle, AIMD would be a valuable tool to address these issues, but its applicability is severely limited by its computational cost, both in terms of the required large system sizes [7] and simulation times. Specifically, the modeling of a bulk Au surface requires slab models of 4-6 atomic layers in thickness [9] with each Au atom having a minimal number of 11 e À . As a result even a simple calculation providing the equivalent surface area to adsorb only four thiolate molecules requires around 600-1000 valence electrons. The current article is aimed at addressing this issue by employing an effective 1 e À valence-electron pseudopotential to emulate the behavior of the bulk gold substrate. The idea follows from the consideration that d electrons [a] Prof.

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Detaching Thiolates from Copper and Gold Clusters: Which Bonds to Break?

Cited by 80 publications

References 61 publications

Quantifying thiol–gold interactions towards the efficient strength control

Quantifying thiol–gold interactions towards the efficient strength control

Gold surfaces and nanoparticles are protected by Au(0)–thiyl species and are destroyed when Au(I)–thiolates form

An Effective Pseudopotential for Modeling Gold Surface Slabs for Ab Initio Simulations

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