Nature and Strength of M−S Bonds (M = Au, Ag, and Cu) in Binary Alloy Gold Clusters

Abstract

The interactions of pure (Au(k), Ag(k), and Cu(k); k = 1-3) and binary alloy (Au(n)Ag(m) and Au(n)Cu(m); m + n = k <or= 3) metal clusters with hydrogen sulfide (H(2)S) have been investigated by using density functional theory (BP86, B3LYP, and CAM-B3LYP) and ab initio methods (MP2 and CCSD(T)), with a focus on the nature of metal-sulfur bonds. Binding energy calculations indicate that for pure metal clusters, the tendency of metal to interact with H(2)S has the order of Au > Cu > Ag. In binary alloy clusters, alloying Au(k) with copper and silver decreases the attraction of Au toward H(2)S, while alloying Ag(k) and Cu(k) by gold increases the attraction of Ag and Cu toward H(2)S, significantly. Dissociation energy values for isolated metal clusters specify the more favorable formation of binary alloy clusters (Au(n)Ag(m) and Au(n)Cu(m)) over pure ones. The nature of M-S bonds (M = Au, Ag, and Cu) is also interpreted by means of the quantum theory of atoms in molecules (QTAIM), natural bond orbital (NBO), and energy decomposition analysis (EDA). According to these theories, the M-S bonds are found to be partially electrostatic and partially covalent. EDA results identify that these bonds have less than 35% covalent character and more than 65% electrostatic, and the covalent character increases in different metals in the order Au > Cu > Ag.

Three-Dimensional Silver(I)-Thiodiglycolate Coordination Polymer with Weak Ag–Ag Bond

“…The Ag-O bond lengths range from 2.2363(3) to 2.470(2) Å ( Table 2) and are in accordance with reported values [19]. Similarly, the Ag-S distance of 2.5679 Å (Ag1-S3 4 ) and 2.5841 (9) Å are also in agreement with the previously reported Ag-S bond distance [20,21]. A closure look at 1 reveals a novel coordination mode of the tdga 2- (Fig.…”

The solubility of copper in high-temperature magmatic vapors: A quest for the significance of various chloride and sulfide complexes

“…Thermochemical data for the solvated species were obtained only on B3LYP level of theory as its performance to predict the binding energies of Cu complexes have been shown to be superior to the MP2 method by several authors (Ignaczak and Gomes, 1996;Luna et al, 2000;Pakiari and Jamshidi, 2010). Indeed, some authors pointed out that the B3LYP theory performs nearly as well or even better on Cu complexes than the computationally much more demanding CCSD(T) level of theory (Luna et al, 2000;Pakiari and Jamshidi, 2010), which almost fully accounts for electron correlation energies. To test the robustness of our results, we conducted CCSD(T)/6-311++G(d,p) level single point energy calculations on the B3LYP/6-311++G(d,p) optimized geometries within the PCM.…”

Aggregation kinetics and cluster structure of amino-PEG covered gold nanoparticles

“…23 Poly(ethylene glycol) derivatives are often used as stabilizers for gold nanoparticles because of their biocompatibility, stealth action, their potential multiple chemical functionality (upon modification) and their ease of grafting due to the high affinity of thiol or amino groups to the gold surface. [24][25][26][27][28] We have recently demonstrated that PEG chains can also be used as a thermoresponsive surface coating at sufficiently high ionic strengths to trigger the clustering of gold particles. 23 In this paper we show how this process can be fine-tuned by adjusting two easily controlled environmental parameters (temperature and ion concentration) that affect the clustering process (kinetics and NPC structure) through modulating colloidal interactions (see Scheme 1).…”