ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation, characterization, and photophysics of the quantum dot well system cadmium sulfide/mercury sulfide/cadmium sulfideA. Mews, A. Eychmueller, M. Giersig, D. Schooss, H. WellerCite this: J. Phys. Chem. 1994, 98, 3, 934–941Publication Date (Print):January 1, 1994Publication History Published online1 May 2002Published inissue 1 January 1994https://pubs.acs.org/doi/10.1021/j100054a032https://doi.org/10.1021/j100054a032research-articleACS...

An extended theoretical approach for calculating the 1s-1s electronic transition in spherically layered semiconductor quantum dots is presented. The extension over common effective-mass approximation includes implementation of Coulomb interaction and finite potential wells at particle boundaries. calculations are carried out quantum-dot well CdS/HgS/CdS compared to recently available experimental results. wave functions electrons holes spreading entire structure probabilities presence...

Small gold cluster anions ${{\mathrm{Au}}_{n}}^{\ensuremath{-}}$ are known for their unusual two-dimensional (2D) structures, giving rise to properties very different from those of bulk gold. Previous experiments and calculations disagree about the number atoms ${n}_{c}$ where transition 3D structures occurs. We combine trapped ion electron diffraction state art electronic structure resolve this puzzle establish ${n}_{c}=12$. It is shown that theoretical studies using traditional generalized...

Gold prospecting: Trapped-ion electron diffraction, photoelectron spectroscopy, and density functional theory are used to establish the structure of free gold cluster ion Au34−. The results suggest a chiral with an internal trigonal pyramid C3 point symmetry.

We report the experimental structure determination of cold, mass selected Ag(55)(+/-) cluster ions using recently developed technique trapped ion electron diffraction. By comparison and theoretical molecular scattering functions consideration computed total energies, we show that Ag(55)(+) constitutes an ideal Mackay icosahedron, whereas Ag(55)(-) is a weakly Jahn-Teller distorted icosahedron. Isomers other structural types, for example, decahedral or close-packed, could be ruled out. The...

Ligand-free metal clusters can be prepared over a wide size range, but only in comparatively small amounts. Determining their size-dependent properties has therefore required the development of experimental methods that allow characterization sample sizes comprising few thousand mass-selected particles under well-defined collision-free conditions. In this review, we describe application these to geometric structural determination Au(n)(+) and Au(n)(-) with n = 3-20. Geometries were assigned...

Structural, electronic, and magnetic properties of the golden cage doped with a transition-metal atom, $M{\text{Au}}_{16}^{\ensuremath{-}}$ ($M=\text{Fe}$,Co,Ni), are investigated using trapped ion electron diffraction, photoelectron spectroscopy, density-functional theory. The best agreement to experiment is obtained for endohedral $M@{\text{Au}}_{16}^{\ensuremath{-}}$ structures but considerable distortions parent ${\text{Au}}_{16}^{\ensuremath{-}}$ cage....

The structures of mass-selected gold cluster anions Au14−–Au19− have been reinvestigated using an improved low temperature trapped ion electron diffraction experiment. Structures were assigned by comparing experimental with simulated scattering functions model obtained density functional calculations. Flat three-dimensional are found for Au14− and Au15−, hollow cages Au16−–Au18− a tetrahedral structure is Au19−. For several clusters in this series, our assignments differ distinctly from...

Correlation of cluster and bulk structure: Electron-diffraction measurements homonuclear 55-atom transition-metal anions covering essentially all 3d 4d elements show only four main structure families. Elements with the same lattice morphology generally have a common type. The types differ in maximum atomic coordination numbers analogy to corresponding lattices. As service our authors readers, this journal provides supporting information supplied by authors. Such materials are peer reviewed...

Electronic (one-photon) photodepletion spectra were recorded for gold cluster anions complexed with one xenon atom over the photon energy range 2.1-3.4 eV. Clusters generated by pulsed laser vaporization and probed under collisionless molecular beam conditions. The obtained are highly structured narrowest features--assigned to individual electronic transitions--having bandwidths of less than 40 meV. Time-dependent density functional theory predictions optically allowed transitions most...

The structures of mass selected silver cluster cations Ag19 +, Ag38 Ag55 Ag59 Ag75 and Ag79 + have been probed at a temperature 100 K by trapped ion electron diffraction. structure assignment is carried out comparison the experimental scattering intensity with theoretical functions calculated candidate obtained density functional theory. For sizes studied resulting data are invariably best described based on icosahedral motif, while closed packed can be ruled out.

The structures and energetics of small tin cluster Snn− anions up to n=15 were determined by a combination density-functional theory three different experimental methods: Ion mobility spectrometry, trapped ion electron diffraction, collision induced dissociation. We find compact, quasispherical n=12. Sn12− is slightly distorted hollow icosahedron while Sn13− Sn15− have prolate structures, consisting merged, hollow, in part incomplete, deltahedral subunits: consists face-sharing pentagonal...

We have studied the gas-phase laser-induced fluorescence of an ensemble buffer gas-cooled Rhodamine 6G cations (R6G(+)) stored in a quadrupole ion trap at 90 K. The resulting from excitation with continuous-wave 488 nm radiation was observed to disappear almost completely on time scale seconds, dependent detail laser fluence. Such decay can be explained by accumulation R6G(+) dark triplet state. This turn facilitates first lifetime determination lowest state free direct ground-state recovery...

The structures of bismuth cluster cations in the range between 4 and 14 atoms have been assigned by a combination gas phase ion mobility trapped electron diffraction measurements together with density functional theory calculations. We find that above 8 clusters adopt prolate coordination numbers 3 highly directional bonds. These open are more like those seen for semiconducting-in-bulk elements (such as silicon) rather than resembling compact typical metallic-in-bulk elements. An accurate...

We have investigated the gas phase triplet state lifetimes and dispersed fluorescence spectra of several types rhodamine cations confined in a quadrupole ion trap thermalized to 85 K. The measured Rh6G(+), Rh575(+), RhB(+), Rh101(+) are found be on order seconds, orders magnitude longer than those typically observed for same dyes optical condensed measurements. In addition emission at K been measured. experimental results as well solution measurements compared density functional calculations...

We report experimental and theoretical studies of the electronic absorption spectra mass selected Au4+⋅Arn (n=0–4) clusters in photon energy range 2.14–3.35 eV. Photodissociation were recorded by monitoring ion depletion upon absorption, yielding absolute photodissociation cross sections. The interpreted comparing them with calculations optical response framework time-dependent density functional theory using cluster structures calculated both (B3-LYP functional) ab initio at RI-MP2 level.

We report an investigation of (CsI)(n)Cs (+) cluster structures (n = 30-39) studied using the recently developed technique trapped ion electron diffraction. Contributions to diffraction from both rock salt (NaCl) and cesium chloride lattice (CsCl) derived isomeric are observed at size n 32. This can form a closed shell rhombic dodecahedron corresponding CsI bulk structure. All other sizes, not equal32, dominated by NaCl Density functional calculations molecular dynamic simulations identify...

We present a comparative study on the structural properties of coinage metal icosamers Cu(20)(+/-), Ag(20)(+/-), and Au(20)(+/-). Using trapped ion electron diffraction measurements in combination with density functional structure calculations we find distinct differences depending cluster material charge state: Cu(20)(-), Cu(20)(+), as well Ag(20)(+) prefer icosahedral structures. Ag(20)(-) adopts rearranged, distorted structure. While Au(20)(-) is tetrahedral, Au(20)(+) cannot be described...

The gas phase structures of tin cluster anions Snn− have been studied by a combination trapped ion electron diffraction and density functional theory calculations. In the size range n=18–25 these clusters comprise dimers stable subunits. particular Sn18− Sn20− are homodimers Sn9 Sn10 subunits, respectively. Sn23− two units linked three additional bridging atoms Sn25− is heterodimer Sn15 This rather unexpected growth mode rationalized extraordinary stability building blocks Sn9, Sn10, Sn15.

The effect of hydrogenation on the structure Ru19– has been studied using a combination trapped ion electron diffraction and density functional computations. While bare cluster closed-shell octahedral geometry, changes type ruthenium core toward an icosahedral motif. experiments show gradual structural transition depending number adsorbed hydrogen atoms. Density theory computations reveal driving force behind this process to be larger adsorption energies for bi-icosahedral predict...

A dual mass gate is described which allows for high resolution separation of ions under realistic laser desorption/ionization and matrix assisted time flight spectrometry conditions at 10 kV kinetic energy. The device consists two interleaved comb units sequentially positioned in the ion beam path. This significant improvement relative to one unit by “low pass” “high functions. Principal limits as given mechanical dimensions electrical properties switches are also discussed.

The structures of ruthenium cluster anions have been investigated using a combination trapped ion electron diffraction and density functional theory computations in the size range from eight to twenty atoms. In this range, three different structural motifs are found: Ru8(-)-Ru12(-) simple cubic structures, Ru13(-)-Ru16(-) form double layered hexagonal larger clusters close packed motifs. For Ru17(-), we find stacking, whereas octahedral occur for Ru18(-)-Ru20(-). Our calculations also...

The photophysics of chromophores is strongly influenced by their environment. Solvation, charge state, and adduct formation significantly affect ground excited state energetics dynamics. present study reports on fluorescence emission rhodamine B cations (RhBH+) derivatives in the gas phase. Substitution acidic proton RhBH+ alkali metal cations, M+, ranging from lithium to cesium leads significant systematic blue shifts emission. gas-phase structures singlet transition energies RhBM+, M = Li,...

Abstract Combining phase‐dependent photoluminescence (PL) measurements and quantum chemical calculations is a powerful approach to help understand the influence of molecular surroundings on PL properties. Herein, phosphine functionalized amidinate was used synthesize recently presented bimetallic gold complex, featuring an unusual charge separation. The latter subsequently as metalloligand yield heterotetrametallic complexes with Au‐M‐M‐Au “molecular wire” arrangement (M=Cu, Ag, Au)...

The structures of platinum cluster anions Pt6--Pt13- have been investigated by trapped ion electron diffraction. Structures were assigned comparing experimental and simulated scattering functions using candidate obtained density functional theory computations, including spin-orbit coupling. We find a structural evolution from planar (Pt6-, Pt7-) amorphous-like (Pt7--Pt9-) to based on distorted tetrahedra (Pt9--Pt11-). Finally, Pt12- Pt13- are hcp fragments. While the parameters well...