The total structure determination of thiol-protected Au clusters has long been a major issue in cluster research. Herein, we report an unusual single crystal 25-gold-atom (1.27 nm diameter, surface-to-surface distance) protected by eighteen phenylethanethiol ligands. Au25 features centered icosahedral Au13 core capped twelve gold atoms that are situated six pairs around the three mutually perpendicular 2-fold axes icosahedron. thiolate ligands bind to exclusive bridging mode. This highly...

We report reversible switching of paramagnetism in a well-defined gold nanoparticle system consisting atomically monodisperse nanoparticles containing 25 atoms protected by 18 thiolates [abbreviated as Au25(SR)18]. The magnetism these can be switched on or off precisely controlling the charge state nanoparticle, that is, magnetic Au25(SR)18 is charge-neutral while nonmagnetic an anionic form particle. Electron paramagnetic resonance (EPR) spectroscopy measurements establish possess one...

Structural, electronic, and optical properties of the thiolate-protected Au38(SR)24 cluster are studied by density-functional theory computations (R = CH3 R C6H13) powder X-ray crystallography C12H25). A low-energy structure which can be written as Au23@(Au(SR)2)3(Au2(SR)3)6 having a bi-icosahedral core chiral arrangement protecting gold−thiolate Au x (SR) y units yields an excellent match between computed (for measured C12H25) diffraction function. We interpret in detail electronic Au23...

Gold and silver nanoclusters have unique molecule-like electronic structure a nonzero HOMO-LUMO gap. Recent advances in X-ray crystal determination led to new understanding of the geometric gold nanoparticles, with significant implications for structure. The superatom model has been effectively employed explain properties such as one- two-photon optical absorption, circular dichroism, EPR spectra, effects introduced by nanoparticle doping. Future investigations may also lead an luminescence,...

Ligand-protected noble metal nanoclusters are of interest for their potential applications in areas such as bioimaging, catalysis, photocatalysis, and solar energy harvesting. These can be prepared with atomic precision, which means that stoichiometries ascertained; the properties these vary significantly depending on exact stoichiometry geometric structure system. This leads to important questions as: What general principles underlie physical nanoclusters? Do hold all systems? "tuned" by...

The atomic arrangement of Au and Ag atoms in Au25-xAgx(SR)18 was determined by X-ray crystallography. were selectively incorporated the 12 vertices icosahedral core. central atom metal six [-SR-Au-SR-Au-SR-] units exclusively gold, with 100% occupancy. composition crystals crystallography Au18.3Ag6.7(SCH2CH2Ph)18. This is reasonable agreement Au18.8Ag6.2(SCH2CH2Ph)18 measured electrospray mass spectrometry. structure can be described terms shells as Au1@Au5.3Ag6.7@6×[-SR-Au-SR-Au-SR-]....

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

The elaborate selection of capping ligands is great importance in the synthesis atomically precise metal nanoclusters. Organic thiolates, alkynyls, phosphines, and/or their combinations are most widely utilized to protect nanoclusters, while inorganic oxo anions have been almost neglected this field. Herein, first CrO42-/ tBuC≡C- co-capped Ag48 nanocluster (SD/Ag48, SD = SunDi) was synthesized and structurally characterized by single-crystal X-ray diffraction. pseudo-5-fold symmetric...

Because of the typical instability copper nanoclusters, atom-precise structural elucidation these nanoclusters has remained elusive. Herein, we report an air- and moisture-stable 23-copper nanocluster (SD/Cu23a or SD/Cu23b) isolated from reaction Cu(CF3COO)2, tBuC≡CH, Cu powder, Ph2SiH2 using a gradient reduction (CuII → CuI Cu0) strategy (GRS), which is competent for controlling kinetics reaction, thus avoiding formation pure complexes large Cu0 nanoparticles. The solid-state structure Cu23...

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 with high PLQY in non-degassed solution at room temperature were constructed by interiorly supporting the core multiple VO43- and E2- anions structure-directing agents exteriorly protecting a rigid ligand shell of PhC≡C- Ph2PE2- (E = S,...

Time-dependent density functional theory calculations are employed to calculate the optical absorption spectra of silver tetrahedral Ag n ( = 10, 20, 35, 56, 84, 120) clusters with emphasis on neutral and ion that correspond shell closings. For 20 cluster, convergence properties respect basis set examined, most accurate results found be in good agreement experimental data. The evolve from molecular-like plasmon-like increasing n, this we able extrapolate plasmon energy width large particle...

A simple one-pot method produces silver nanoparticles coated with aryl thiols that show intense, broad nonplasmonic optical properties. The synthesis works many aryl-thiol capping ligands, including water-soluble 4-mercaptobenzoic acid. produced linear absorption is broader, stronger, and more structured than most conventional organic inorganic dyes. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents peer-reviewed, but not copy-edited...

Time-dependent density functional theory calculations at the SAOP/TZP level of are employed to study optical absorption spectra pure metal nanoparticles (Au25(SH)18− and Ag25(SH)18−) mixed "core-shell" systems (Au13Ag12(SH)18− Ag13Au12(SH)18−). All four exhibit discrete spectra. The splitting between LUMO LUMO+1 HOMO HOMO−1 varies markedly with used in core oligomeric thiolate ligands. not separable into ligand contributions; geometric electronic interactions two fragments responsible for complex

Microsolvation and combined microsolvation-continuum approaches are employed in order to examine the structures relative energies of nonionized (N) zwitterionic (Z) glycine clusters. Bridging predicted be global minima after 3-5 discrete water molecules included calculations. Calculations incorporating electron correlation stabilize by about 7-9 kcal/mol N regardless number considered. Continuum calculations Z structures; this effect decreases as is increased. Eight do not appear fully...

We present time dependent density functional theory (TDDFT) calculations for a tetrahedral Au20 complex interacting with pyridine the purpose of modeling absorption and surface enhanced Raman scattering, emphasis on chemical electrodynamic enhancement effects. These are done using ADF code BP86 functional, zeroth-order regular approximation resonant electronic response modeled short expression perturbed matrix, damping factor that is empirically chosen. The spectrum bare shows strong...

Density functional theory calculations are employed to calculate geometries (R = H, CH3, CH2CH3, CH2CH2Ph) and excitation energies CH2CH3) for the Au25(SR)18− nanoparticle. The splitting between first two peaks in optical absorption spectrum is known arise as a result of ligand-field superatom D orbitals, value this found be very sensitive probe gold−gold distances Au25(SH)18− nanoparticle core. LDA functionals such Xα with triple-ζ basis set predict core good agreement experiment, which...

Abstract Two pure silver nanoparticles (Ag 210 ( i PrPhS) 71 (Ph 3 P) 5 Cl and Ag 211 6 labeled as SD/Ag210 SD/Ag211 (SD=SunDi), were found to co‐crystallize in forming compound 1 . Single‐crystal X‐ray diffraction (SCXRD) revealed that they differ by only one Ag(PPh ). Their four‐shell consist of three metal shells 19 @Ag 52 45 ) shielded a silver‐organic 89 Cl[Ag(Ph P)] n outermost shell. The number Ag(Ph is five for six SD/Ag211. pseudo‐fivefold symmetric exhibit surface plasmon...

The surface plasmon resonance (SPR) of noble metal nanoparticles is reviewed in terms both classical and quantum mechanical approaches. collective oscillation the free electrons responsible for well described using electromagnetic theory large systems (from about 10 to 100 nm). In cases where effects are important, this fails first principle approaches like time-dependent density functional (TDDFT) must be used. paper, we give an account current understanding origin resonances. We provide...

Due to distinctive quantum confinement effects, ultrasmall gold nanoparticles usually exhibit interesting electronic structure and molecular-like properties. However, the lack of atomically-precise structural information makes understanding them almost impossible, such as relationships between their compositions unique Herein, by reducing a diphosphine AuI precursor (Au2(dppm)2Cl2; dppm = Ph2PCH2PPh2) with or without S2- releasing reagent, we enriched our knowledge members in families Au13...

A ligand exchange strategy has been employed to understand the role of ligands on structural and optical properties atomically precise 29 atom silver nanoclusters (NCs). By optimization, ∼44-fold quantum yield (QY) enhancement Ag29(BDT)12–x(DHLA)x NCs (x = 1–6) was achieved, where BDT DHLA refer 1,3-benzene-dithiol dihydrolipoic acid, respectively. High-resolution mass spectrometry used monitor exchange, structures different were obtained through density functional theory (DFT). The DFT...

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

Thiacalix[4]arenes have emerged as a family of macrocyclic ligands to protect metal nanoparticles, but it remains great challenge solve the mystery their structures at atomic level, especially for those larger than 2 nm. Here, we report largest known mixed-valence silver nanocluster [Ag155 (CyS)40 (TC4A)5 Cl2 ] (Ag155) protected by deprotonated cyclohexanethiol (CySH) and ligand p-tert-butylthiacalix[4]arene (H4 TC4A). Its single-crystal structure consists metallic core four concentric...

Abstract Herein, two atomically precise silver nanoclusters, Ag54 and Ag33 , directed by inner anion templates (CrO 4 2− and/or Cl − ), are initially isolated as a mixed phase from identical reactants across wide temperature range (20–80 °C). Interestingly, fine‐tuning the reaction can realize pure synthesis of nanoclusters; that is, metastable is kinetically formed at low (20 °C), whereas such system steered towards thermodynamically stable relatively high (80 Electrospray ionization mass...