Gas-phase photoelectron spectroscopy( PES) was conducted on [XAg 24 (SPhMe 2 ) 18 ] À (X = Ag, Au) and [YAg 24 -(SPhMe 2 ) 18 ] 2À (Y = Pd, Pt), which have aformal superatomic core (X@Ag 12 ) 5+ or (Y@Ag 12 ) 4+ with icosahedral symmetry. PES results show that superatomic orbitals in the (Au@Ag 12 ) 5+ core remain unshifted with respect to those in the (Ag@Ag 12 ) 5+ core,whereas the orbitals in the (Y@Ag 12 ) 4+ (Y = Pd, Pt) core shift up in energy by about 1.4 eV.T he remarkable doping effect of asingle Yatom (Y = Pd, Pt) on the electronic structure of the chemically modified (Ag@Ag 12 ) 5+ superatom was reproduced by theoretical calculations on simplified model systems and was ascribed to 1) the weaker binding of valence electrons in Y@(Ag + ) 12 compared to Ag + @(Ag + ) 12 due to the reduction in formal charge of the core potential, and 2) the upward shift of the apparent vacuum level due to the presence of ar epulsive Coulomb barrier between [YAg 24 (SPhMe 2 ) 18 ] À and electron.Thiolate (RS)-or dithiolate (RS 2 )-protected silver clusters, such as [Ag 25 (SR) 18 ] À , [1] [Ag 29 (S 2 R) 12 ] 3À , [2] and [Ag 44 -(SR) 30 ] 4À , [3][4][5] are an emerging class of nanomaterials.S inglecrystal X-ray diffraction (SCXRD) analysis showed that [Ag 25 (SR) 18 ] À and [Ag 29 (S 2 R) 12 ] 3À have an icosahedral Ag 13 core (Scheme 1), [1,2] whereas [Ag 44 (SR) 30 ] 4À has at wo-shell Keplerate Ag 32 core. [5] TheA g 13 and Ag 32 cores form the closed-shell electronic configurations (1S) 2 (1P) 6 and (1S) 2 -(1P) 6 (1D) 10 ,r espectively:1 S, 1P,a nd 1D represent superatomic orbitals with angular momenta of 0, 1, and 2, respectively. [6] Structural similarities to gold analogues indicate that the thiolate-protected Ag clusters represent another family of chemically modified superatoms. [7][8][9] Thiolate-protected Ag clusters have attracted researchers due to specific properties such as photoluminescence [10] although they are generally less stable than the gold analogues.Doping with heteroatoms is apromising approach to enhance the stability and further improve the properties of the Ag clusters.S tate-of-the-art synthesis based on coreduction [11,12] and galvanic replacement [13,14] allowed us to precisely define the number, element, and location of the heteroatom(s) introduced into the Ag clusters.F or example, as ingle Ma tom (M = Au,P d, Pt) can be integrated exclusively at the central position of an icosahedral Ag 13 core of [Ag 25 (SPhMe 2 ) 18 ] À[1] to form M@Ag 12 cores in [AuAg 24 (SPhMe 2 ) 18 ] À[13] and [MAg 24 (SPhCl 2 ) 18 ] 2À (M = Pd, Pt) [11] (Scheme 1). Both the undoped Ag 13 and doped M@Ag 12 cores form ac losed electron configuration, (1S) 2 -(1P) 6 .These atomically defined bimetallic clusters provide an ideal platform to study the effect of single-atom doping on their properties.O ptical spectroscopy (Figure 1a)a nd voltammetry [15] showed that the doping slightly modulates the HOMO-LUMO gap of [Ag 25 (SPhMe 2 ) 18 ] À .T he stability [13,15] and photoluminescence quantum yield (PLQY) [10] of [A...

This perspective summarizes our recent efforts in the application of gas-phase characterization methods to ligand-protected Au/Ag clusters chemically synthesized with atomic precision.

Photoelectron (PE) spectra of thiolate-protected coinage metal clusters [Au25(SC2H4Ph)18]− and [Ag25(SPhMe2)18]− isolated in vacuum were recorded at 355 and 266 nm. Their adiabatic electron affinities were determined to be 2.36 ± 0.01 and 2.02 ± 0.02 eV, respectively, from the onsets of the PE spectra recorded at 355 nm. Upon irradiation with a 266 nm light, the emission of slow electrons was observed as the major process, while suppressing the direct electron detachment and dissociation into anionic fragments. Curve fitting analysis of the PE spectra at 266 nm suggests that the slow electron emission is assigned to thermionic emission (TE) from the vibrationally hot M13 core in [M25(SR)18]− (M = Au, Ag). The novel photoinduced TE observed here is ascribed to the selective transition to an electronically excited state [M25(SR)18]−* embedded in the electron detachment continuum followed by quick internal conversion to a vibrationally excited state in the electronically ground state.

“Patchy particles”, where the surface is anisotropically patterned through variation in the surface composition, can assemble into different colloidal crystal structures as well as act as interface stabilizers, heterogeneous reaction catalysts, and targeted drug delivery agents. Patchy nanoparticles (NPs) can be formed by adsorbing two chemically different polymer chains that will spontaneously phase separate. Although there is growing interest in polymer-based patchy nanoparticles, the majority of the studies have been theoretical rather than experimental due to difficulties in preparing significant quantities of nanoparticles with controlled polymer ratios. Likewise, characterization of the phase separation on the nanoparticle surface is challenging. Here we simultaneously overcome the synthesis and characterization hurdles by developing a facile, versatile protocol to produce sufficient quantities of patchy NPs for quantitative solid-state NMR measurements of the patch fractions, degree of phase separation, and morphology. Monodisperse 3.5 nm ZrO2 nanocrystals with polystyrene (PS) and poly­(ethylene oxide) (PEO) ligands, covering the entire possible composition range, were reproducibly prepared through a simple exchange process. This approach has the advantage of well-defined polymer molecular weights and NP sizes, allowing experimental validation of theoretical predictions for nanophase separation in NPs with mixed homopolymer brushes. Upon exposure to a nonselective solvent, the nanoparticles assemble into different morphologies, namely micelles and vesicles, as a function of the PEO:PS ratios.