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.

Toward quantitative electronic structure in small gold nanoclusters.

Ligand-protected gold nanoclusters (AuNCs) feature a dense but finite electronic structure that can be rationalized using qualitative descriptions such as the well-known superatomic model and predicted using quantum chemical calculations. However, the lack of well-resolved experimental probes of a AuNC electronic structure has made the task of evaluating the accuracy of electronic structure descriptions challenging. We compare electronic absorption spectra computed using time-dependent density functional theory to recently collected high resolution experimental spectra of Au(PPh) and Au(PPh) AuNCs with strikingly similar features.

Impact of Ligands on Structural and Optical Properties of Ag Nanoclusters.

A ligand exchange strategy has been employed to understand the role of ligands on the structural and optical properties of atomically precise 29 atom silver nanoclusters (NCs). By ligand optimization, ∼44-fold quantum yield (QY) enhancement of Ag(BDT)(DHLA) NCs ( = 1-6) was achieved, where BDT and DHLA refer to 1,3-benzene-dithiol and dihydrolipoic acid, respectively. High-resolution mass spectrometry was used to monitor ligand exchange, and structures of the different NCs were obtained through density functional theory (DFT).

Luminescence and Electron Dynamics in Atomically Precise Nanoclusters with Eight Superatomic Electrons.

The [Au(SR)] and [Au(dppe)Cl] [dppe = 1,2-bis(diphenylphosphino)ethane] nanoclusters both possess a 13-atom icosahedral core with 8 delocalized superatomic electrons (8e), but their emission properties and time-resolved electron dynamics differ significantly. In this work, experimental photoluminescence and photoluminescence decay measurements are combined with time-dependent density functional theory calculations of radiative and nonradiative decay properties and lifetimes to elucidate the similarities and differences in the emission of these two nanoclusters with similar cores. In this work, the photodynamic properties of [Au(dppe)Cl] are elucidated theoretically for the first time.

Theoretical Investigation of Water Oxidation Mechanism on Pure Manganese and Ca-Doped Bimetal Oxide Complexes.

Understanding the role of Ca ion in the oxygen-evolving complex of photosystem II is essential to design commercially viable and efficient water oxidation catalysts. To this end, small pure manganese oxide and calcium-doped manganese oxide model complexes saturated with water-derived ligands are investigated in this work. Density functional theory calculations are performed to investigate the water oxidation process on Mn(μ-OH)(μ-O)(HO)(OH) (MnO·6HO) and CaMnO(μ-OH)(HO)(OH) (CaMnO·7HO) complexes.

Connections Between Theory and Experiment for Gold and Silver Nanoclusters.

Ligand-stabilized gold and silver nanoparticles are of tremendous current interest in sensing, catalysis, and energy applications. Experimental and theoretical studies have closely interacted to elucidate properties such as the geometric and electronic structures of these fascinating systems. In this review, the interplay between theory and experiment is described; areas such as optical absorption and doping, where the theory-experiment connections are well established, are discussed in detail; and the current status of these connections in newer fields of study, such as luminescence, transient absorption, and the effects of solvent and the surrounding environment, are highlighted.

Theoretical Insights into the Origin of Photoluminescence of Au25(SR)18(-) Nanoparticles.

Understanding fundamental behavior of luminescent nanomaterials upon photoexcitation is necessary to expand photocatalytic and biological imaging applications. Despite the significant amount of experimental work into the luminescence of Au25(SR)18(-) clusters, the origin of photoluminescence in these clusters still remains unclear. In this study, the geometric and electronic structural changes of the Au25(SR)18(-) (R = H, CH3, CH2CH3, CH2CH2CH3) nanoclusters upon photoexcitation are discussed using time-dependent density functional theory (TD-DFT) methods.

Strong Tunable Visible Absorption Predicted for Polysilo-acenes Using TDDFT Calculations.

The optical properties of polysilo-acenes with two to six fused rings are studied using time-dependent density functional theory. We show that there are three spectral features in the absorption spectra analogous to α, β, and p-band peaks known for carbon-based acenes. The β peak is the most prominent feature in each spectrum, which appears in the visible region.