Effect of Ni-Doping on the Optical, Structural, and Electrochemical Properties of Ag Nanoclusters.

Atomically precise metal nanoclusters (NCs) can be compositionally controlled at the single-atom level, but understanding structure-property correlations is required for tailoring specific optical properties. Here, the impact of Ni atom doping on the optical, structural, and electrochemical properties of atomically precise 1,3-benzene dithiol (BDT) protected Ag NCs is studied. The Ni-doped Ag (NiAg(BDT)) NCs, are synthesized using a co-reduction method and characterized using electrospray ionization mass spectrometry (ESI MS), ion mobility spectrometry (IMS), and X-ray photoelectron spectroscopy (XPS).

Silvery fullerene in Ag nanosaucer.

Despite the discovery of a series of fullerenes and a handful of noncarbon clusters with the typical topology of -C, the smallest fullerene with a large degree of curvature, C, and its other-element counterparts are difficult to isolate experimentally. In coinage metal nanoclusters (NCs), the first all-gold fullerene, Au, was discovered after a long-lasting pursuit, but the isolation of similar silvery fullerene structures is still challenging. Herein, we report a flying saucer-shaped 102-nuclei silver NC () with a silvery fullerene kernel of Ag, which is embraced by a robust cyclic anionic passivation layer of (KPO).

Implementation of energy and gradient for the TDDFT-approximate auxiliary function (aas) method.

In this work, we have implemented the time-dependent density functional theory approximate auxiliary s function (TDDFT-aas) method, which is an approximate TDDFT method. Instead of calculating the exact two-center electron integrals in the K coupling matrix when solving the Casida equation, we approximate the integrals, thereby reducing the computational cost. In contrast to the related TDDFT plus tight-binding (TDDFT+TB) method, a new type of gamma function is used in the coupling matrix that does not depend on the tight-binding parameters.

Effects of Nanowire Doping on Plasmon-Enhanced N Dissociation.

Doping a transition metal element into plasmonic systems can tune the optical properties of the system, which will potentially facilitate the plasmon-enhanced catalytic process. In this study, we applied the linear-response time-dependent density functional theory (LR-TDDFT) method with real-time electron dynamics and mean-field Ehrenfest dynamics methods to computationally investigate the effects of doping silver nanowires on plasmon-enhanced N dissociation. We calculated the absorption spectra for different doped systems, applied an external electric field to the system, and performed mean-field Ehrenfest dynamics to examine how plasmonic excitation will affect the N activation or dissociation.

Effects of Static Electric Fields on the Excitations of Silver Nanowire Dimers.

We theoretically studied the introduction of static electric fields to Ag nanowire dimer systems, including the effects of this field on optical absorption characteristics and the orbitals responsible for these excitations. Linear-response time-dependent density functional theory computations were performed on three distinct dimer systems: end-to-end, parallel, and 90° angle dimer systems separated by a closest interparticle distance of 7.0 Å.

Temperature-Controlled Selective Formation of Silver Nanoclusters and Their Transformation to the Same Product.

Herein, two atomically precise silver nanoclusters, Ag54 and Ag33, directed by inner anion templates (CrO and/or Cl), are initially isolated as a mixed phase from identical reactants across a wide temperature range (20-80 °C). Interestingly, fine-tuning the reaction temperature can realize pure phase synthesis of the two nanoclusters; that is, a metastable Ag54 is kinetically formed at a low temperature (20 °C), whereas such a system is steered towards a thermodynamically stable Ag33 at a relatively high temperature (80 °C). Electrospray ionization mass spectrometry illustrates that the stability of Ag33 is superior to that of Ag54, which is further supported by density functional theory calculations.

Biomimetic crystallization for long-pursued -COOH-functionalized gold nanocluster with near-infrared phosphorescence.

As an interdisciplinary product, water-soluble gold nanoclusters (AuNCs) stabilized by ligands containing carboxyl (-COOH) group have garnered significant attention from synthetic chemists and biologists due to their immense potential for biomedical applications. However, revealing the crystallographic structures of -COOH-functionalized AuNCs remains a bottleneck. Herein, we successfully applied the salting-out method to obtain a series of high-quality single crystals of -COOH-functionalized Au nanoclusters and revealed their crystallographic structures.

Understanding the Ligand-Dependent Photoluminescent Mechanism in Small Alkynyl-Protected Gold Nanoclusters.

Alkynyl-protected gold clusters have recently gained attention because they are more structurally versatile than their thiolate-protected counterparts. Despite their flexibility, however, a higher photoluminescent quantum yield (PLQY) has been observed experimentally compared to that of organically soluble thiolate-protected clusters. Previous experiments have shown that changing the organic ligand, or R group, in these clusters does not affect the geometric or electronic properties of the core, leading to a similar absorption profile.

Chiral and Achiral Crystal Structures of Au (PET) Reveal Effects of Ligand Rotational Isomerization on Optoelectronic Properties.

The crystal structures of 4 ligand-rotational isomers of Au (PET) are presented. Two new ligand-rotational isomers are revealed, and two higher-quality structures (allowing complete solution of the ligand shell) of previously solved Au (PET) clusters are also presented. One of the structures lacks an inversion center, making it the first chiral Au (SR) structure solved.

Effects of Field Strength and Silver Nanowire Size on Plasmon-Enhanced N Dissociation.

Dissociation of the nitrogen molecule via plasmon-enhanced catalysis using noble metal nanoparticles has been investigated both experimentally and computationally in recent years. However, the mechanism of plasmon-enhanced nitrogen dissociation is still not very clear. In this work, we apply theoretical approaches to examine the dissociation of a nitrogen molecule on atomically thin Ag nanowires ( = 6, 8, 10, 12) and a Ag nanorod.

Analytical excited state gradients for time-dependent density functional theory plus tight binding (TDDFT + TB).

Understanding photoluminescent mechanisms has become essential for photocatalytic, biological, and electronic applications. Unfortunately, analyzing excited state potential energy surfaces (PESs) in large systems is computationally expensive, and hence limited with electronic structure methods such as time-dependent density functional theory (TDDFT). Inspired by the sTDDFT and sTDA methods, time-dependent density functional theory plus tight binding (TDDFT + TB) has been shown to reproduce linear response TDDFT results much faster than TDDFT, particularly in large nanoparticles.

A first glance into mixed phosphine-stibine moieties as protecting ligands for gold clusters.

Atomically precise gold clusters have attracted considerable research interest as their tunable structure-property relationships have resulted in widespread applications, from sensing and biomedicine to energetic materials and catalysis. In this article, the synthesis and optical properties of a novel [Au(SbP)][PF] cluster are reported. Despite the lack of spherical symmetry in the core, the cluster shows exceptional thermal and chemical stability.

Theoretical Investigations on the Plasmon-Mediated Dissociation of Small Molecules in the Presence of Silver Atomic Wires.

Plasmonic nanoparticles can promote bond activation in adsorbed molecules under relatively benign conditions via excitation of the nanoparticle's plasmon resonance. As the plasmon resonance often falls within the visible light region, plasmonic nanomaterials are a promising class of catalysts. However, the exact mechanisms through which plasmonic nanoparticles activate the bonds of nearby molecules are still unclear.

Effects of Diglyme on Au Nanocluster Formation: Mechanism, H NMR, and Bonding.

Recently, diglyme was applied as a solvent in the synthesis of a luminescent gold-thiolate nanocluster. However, the interactions between the diglyme and the gold nanocluster and the intrinsic mechanism of the diglyme-assisted nanocluster growth have not been examined. In this work, we use density functional theory (DFT) to propose a plausible pathway for diglyme-assisted Au(I)-thiolate synthesis; the reaction energies are found to be negative in every step.

Characterization of Pt-doping effects on nanoparticle emission: a theoretical look at AuPt(SH) and AuPt(SCH).

Developments in nanotechnology have made the creation of functionalized materials with atomic precision possible. Thiolate-protected gold nanoclusters, in particular, have become the focus of study in literature as they possess high stability and have tunable structure-property relationships. In addition to adjustments in properties due to differences in size and shape, heteroatom doping has become an exciting way to tune the properties of these systems by mixing different atomic d characters from transition metal atoms.

Sulfide Boosting Near-Unity Photoluminescence Quantum Yield of Silver Nanocluster.

Silver nanoclusters have emerged as promising candidates for optoelectronic applications, but their room-temperature photoluminescence quantum yield (PLQY) is far from ideal to access cutting-edge device performance. Herein, two supertetrahedral silver nanoclusters with high PLQY in non-degassed solution at room temperature were constructed by interiorly supporting the core with multiple VO and E anions as structure-directing agents and exteriorly protecting the core with a rigid ligand shell of PhC≡C and PhPE (E = S, ; E = Se, ). Both clusters have similar outer Ag tetrahedral cages and [AgE@(VO)] cores, forming a pair of comparable clusters to decrypt the origin of such a high PLQY, particularly in , where the PLQY reached up to 97%.

An ultrastable thiolate/diglyme ligated cluster: Au(PET)(DG).

The synthesis and characterization of an Au(PET)(DG) (PET = phenylethane thiol; DG = diglyme) cluster is reported. Mass spectrometry reveals this as the first diglyme ligated cluster where diglyme ligands survive ionization into the gas phase. Thermal analysis shows the cluster degrades at 156 °C, whereas the similar Au(PET) cluster degrades at 125 °C, representing markedly increased thermal stability.

An Ultrastable 155-Nuclei Silver Nanocluster Protected by Thiacalix[4]arene and Cyclohexanethiol for Photothermal Conversion.

Thiacalix[4]arenes have emerged as a family of macrocyclic ligands to protect metal nanoparticles, but it remains a great challenge to solve the mystery of their structures at the atomic level, especially for those larger than 2 nm. Here, we report the largest known mixed-valence silver nanocluster [Ag (CyS) (TC4A) Cl ] (Ag155) protected by deprotonated cyclohexanethiol (CySH) and macrocyclic ligand p-tert-butylthiacalix[4]arene (H TC4A). Its single-crystal structure consists of a metallic core of four concentric shells, Ag @Ag @Ag @Ag , lined with a organic skin of 40CyS and 5TC4A and 2Cl .

Plasmon-induced excitation energy transfer in silver nanoparticle dimers: A real-time TDDFTB investigation.

Using real-time quantum dynamics calculations, we perform theoretical investigations of light-induced interactions and electronic excitation transfer in a silver nanoparticle dimer. Real-time time-dependent density functional tight-binding (RT-TDDFTB) calculations provide details of the quantum dynamical processes at an electronic/atomistic level with attosecond resolution. The computational efficiency of RT-TDDFTB allows us to examine electronic dynamics up to picosecond time scales.

Time-dependent density functional theory study of the optical properties of tetrahedral aluminum nanoparticles.

The plasmonic properties of tetrahedral aluminum nanoparticles have been investigated using time-dependent functional theory (TDDFT) calculations. The excitation energies are calculated for tetrahedral aluminum nanoparticles (Al , n = 10-120) with different charge states. The BP86/DZ model is used to perform geometric optimization calculations for these clusters.

Crystal Structure and Optical Properties of a Chiral Mixed Thiolate/Stibine-Protected Au Cluster.

We report the first example of a chiral mixed thiolate/stibine-protected gold cluster, formulated as Au(S-Adm)(SbPh)Br (where S-Adm = 1-adamantanethiolate). Single crystal X-ray crystallography reveals the origin of chirality in the cluster to be the introduction of the rotating arrangement of Au(S-Adm) and Au(S-Adm) staple motifs on an achiral Au core and the subsequent capping of the remaining gold atoms by SbPh and Br ligands. Interestingly, the structure and properties of this new Au cluster are found to be different from other reported achiral Au clusters and the only other stibine-protected [Au(SbPh)Cl] cluster.