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Insufficient binding selectivity of chemosensors often renders biorelevant metabolites indistinguishable by the widely used indicator displacement assay. Array-based chemosensing methods are a common workaround but require additional effort for synthesizing a chemosensor library and setting up a sensing array. Moreover, it can be very challenging to tune the inherent binding preference of macrocyclic systems such as cucurbit[n]urils (CBn) by synthetic means. Using a novel cucurbit[7]uril-dye conjugate that undergoes salt-induced adaptation, we now succeeded in distinguishing 14 bioorganic analytes from each other through the facile stepwise addition of salts. The salt-specific concentration-resolved emission provides additional information about the system at a low synthetic effort. We present a data-driven approach to translate the human-visible curve differences into intuitive pairwise difference measures. Ion mobility experiments combined with density functional theory calculations gave further insights into the binding mechanism and uncovered an unprecedented ternary complex geometry for CB7. TThis work introduces the non-selectively binding, salt-adaptive cucurbit[n]uril system for sensing applications in biofluids such as urine, saliva, and blood serum.

Electrospray ionization of THF solutions of preformed [K(18-c-6)][M(COT)

Reaction of the ethynyl compound [{HCCC(NDipp)2}2Au2] with n-BuLi followed by Cp2MCl2 (M = Ti, Zr) leads to two group IV – gold(i) heterobimetallic complexes with different photoluminescence properties.

A new class of flexible tetranuclear copper nanoclusters protected by carborane-thiols having stimuli-responsive tunable solid state phosphorescence.

We compare the intersystem crossing rate

A unique feature of the work carried out in the Collaborative Research Center 3MET continues to be its emphasis on innovative, advanced experimental methods which hyphenate mass‐selection with further analytical tools such as laser spectroscopy for the study of isolated molecular ions. This allows to probe the intrinsic properties of the species of interest free of perturbing solvent or matrix effects. This review explains these methods and uses examples from past and ongoing 3MET studies of specific classes of multicenter metal complexes to illustrate how coordination chemistry can be advanced by applying them. As a corollary, we will show how the challenges involved in providing well‐defined, for example monoisomeric, samples of the molecular ions have helped to further improve the methods themselves thus also making them applicable to many other areas of chemistry., Advances in spectroscopic and computational methodologies have made possible the illustrated threefold synergetic approach which is considerably boosting our understanding of oligonuclear TM compounds. This review describes several of the corresponding advances in spectroscopic methodologies as related to studies of charged 3MET complexes in gas‐phase.

We investigated the structural and spectroscopic properties of singly deprotonated biliverdin anions in vacuo, using a combination of cryogenic ion spectroscopy, ion mobility spectrometry, and density functional theory. The ion mobility results show that at least two conformers are populated, with the dominant conformer at 75-90% relative abundance. The vibrational NH stretching signatures are sensitive to the tetrapyrrole structure, and they indicate that the tetrapyrrole system is in a helical conformation, consistent with simulated ion mobility collision cross sections. The vibrational spectrum in the fingerprint region of this singly deprotonated species shows that the two propionate groups share the remaining acidic proton. The S1 band of the electronic spectrum in vacuo is broad, despite ion trap temperatures of 20 K during ion preparation, with a congested Franck-Condon envelope showing partially resolved vibrational features. The vertical transition exhibits a small solvatochromic red shift (-320 cm-1) in aqueous solution.

Combining phase‐dependent photoluminescence (PL) measurements and quantum chemical calculations is a powerful approach to help understand the influence of the molecular surroundings on the PL properties. Herein, a phosphine functionalized amidinate was used to synthesize a recently presented bimetallic gold complex, featuring an unusual charge separation. The latter was subsequently used as metalloligand to yield heterotetrametallic complexes with an Au‐M‐M‐Au “molecular wire” arrangement (M=Cu, Ag, Au) featuring metallophilic interactions. All compounds show bright phosphorescence in the solid state, also at ambient temperature. The effect of the molecular environment on the PL was studied in detail for these tetrametallic complexes by comparative measurements in solution, in the solid state and in the gas phase and contrasted to time‐dependent density functional theory computations., The photoluminescence of Au‐M‐M‐Au (M=Cu, Ag, Au) “molecular wire” complexes was studied in detail by comparative measurements in solution, in the solid state and in the gas phase and contrasted to time‐dependent density functional theory computations.

We present a straightforward and generally applicable synthesis route for cofacially linked homo‐ and heterotrimetallic trisporphyin complexes. The protocol encompasses synthesising the first aryl‐based, trans‐o‐phenylene trisporphyrin starting from pyrrole and benzaldehyde with an overall yield of 3.6 %. It also allows investigating the respective cis‐isomer as the first conformationally restricted planar‐chiral trisporphyrin. The free‐base ligand was used in subsequent metalation reactions to afford the corresponding homotrimetallic Mn(III)‐, Fe(III)‐, Ni(II)‐, Cu(II)‐, Zn(II)‐ and Pd(II) complexes – additionally, a small adaptation of the protocol resulted in the defined Ni(II)Fe(III)Ni(II) complex in a total yield of 2.3 %. By monitoring Ni(II) insertion into the empty trimeric ligands, we affirmed that the outer porphyrin rings are filled before the internal ring. The molecular species were characterised by 1H NMR, UV‐Vis, photoluminescence, IR, MS, CID, and high‐resolution IMS measurements., A synthesis route for cofacially linked homo‐ and heterotrimetallic trisporphyin complexes starting from pyrrole and benzaldehyde is presented in this work. Besides the novel aryl‐based, trans‐o‐phenylene trisporphyrin, we investigated the respective cis‐isomer as the first conformationally restricted planar‐chiral trisporphyrin. The homotrimetallic Mn(III)‐, Fe(III)‐, Ni(II)‐, Cu(II)‐, Zn(II)‐ and Pd(II) complexes and the defined Ni(II)Fe(III)Ni(II) heterotrimetalic complex were synthesized, the metal ion insertion process studied and the resulting compounds investigated by e. g. UV‐Vis, photoluminescence or high‐resolution IMS measurements.

We present a novel, straightforward method to determine the enantiomeric excess (ee) of tryptophan (Trp) and

Chiral magnetic materials are proposed for applications in second‐order non‐linear optics, magneto‐chiral dichroism, among others. Recently, we have reported a set of tetra‐nuclear Fe(II) grid complex conformers with general formula C/S‐[Fe4L4]8+ (L: 2,6‐bis(6‐(pyrazol‐1‐yl)pyridin‐2‐yl)‐1,5‐dihydrobenzo[1,2‐d : 4,5‐d′]diimidazole). In the grid complexes, isomerism emerges from tautomerism and conformational isomerism of the ligand L, and the S‐type grid complex is chiral, which originates from different non‐centrosymmetric spatial organization of the trans type ligand around the Fe(II) center. However, the selective preparation of an enantiomerically pure grid complex in a controlled manner is difficult due to spontaneous self‐assembly. To achieve the pre‐synthesis programmable resolution of Fe(II) grid complexes, we designed and synthesized two novel intrinsically chiral ligands by appending chiral moieties to the parent ligand. The complexation of these chiral ligands with Fe(II) salt resulted in the formation of enantiomerically pure Fe(II) grid complexes, as unambiguously elucidated by CD and XRD studies. The enantiomeric complexes exhibited similar gradual and half‐complete thermal and photo‐induced SCO characteristics. The good agreement between the experimentally obtained and calculated CD spectra further supports the enantiomeric purity of the complexes and even the magnetic studies. The chiral resolution of Fe(II)‐ [2×2] grid complexes reported in this study, for the first time, might enable the fabrication of magneto‐chiral molecular devices., The trans ‐type ligand wrapping around the metal centers in an inter‐woven style makes the complex to be in chiral. This separation of Λ and Δ forms of spin‐crossover isomers was successfully achieved by appending the chiral moiety onto the parent ligand. The presence of spin‐crossover and chirality makes these multifunctional complexes intriguing for the study of magneto‐optical effects.

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 Ag29(BDT)12-x(DHLA)x NCs (x = 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). The DFT results from Ag29(BDT)11(DHLA) NCs were further experimentally verified through collisional cross-section (CCS) analysis using ion mobility mass spectrometry (IM MS). An excellent match in predicted CCS values and optical properties with the respective experimental data led to a likely structure of Ag29(DHLA)12 NCs consisting of an icosahedral core with an Ag16S24 shell. Combining the experimental observation with DFT structural analysis of a series of atomically precise NCs, Ag29-yAuy(BDT)12-x(DHLA)x (where y, x = 0,0; 0,1; 0,12 and 1,12; respectively), it was found that while the metal core is responsible for the origin of photoluminescence (PL), ligands play vital roles in determining their resultant PLQY.

The kinetics of intercluster metal atom exchange reactions between solvated [Ag25(DMBT)18]- and [Au25(PET)18]- (DMBT and PET are 2,4-dimethylbenzenethiol and 2-phenylethanethiol, respectively, both C8H10S) were probed by electrospray ionization mass spectrometry and computer-based modeling. Anion mass spectra and collision induced dissociation (CID) measurements show that both cluster monomers and dimers are involved in the reactions. We have modeled the corresponding kinetics assuming a reaction mechanism in which metal atom exchange occurs through transient dimers. Our kinetic model contains three types of generic reactions: dimerization of monomers, metal atom exchange in the transient dimers, and dissociation of the dimers to monomers. There are correspondingly 377 discrete species connected by in total 1302 reactions (i.e., dimerization, dissociation and atom exchange reactions) leading to the entire series of monomeric and dimeric products [AgmAu25-m]- (m = 1-24) and [AgmAu50-m]2- (m = 0-50), respectively. The rate constants of the corresponding reactions were fitted to the experimental data, and good agreement was obtained with exchange rate constants which scale with the probability of finding a silver or gold atom in the respective monomeric subunit of the dimer, i.e., reflecting an entropic driving force for alloying. Allowing the dimerization rate constant to scale with increasing gold composition of the respective reactants improves the agreement further. The rate constants obtained are physically plausible, thus strongly supporting dimer-mediated metal atom exchange in this intercluster reaction system.

Among the solution-based purification methods of as-produced single-walled carbon nanotubes (SWCNTs), conjugated polymer sorting is one of the most promising approaches to obtain semiconducting SWCNTs (s-SWCNTs) with high purity. In order to meet the demand for pure polymer-free s-SWCNTs after polymer wrapping, we synthesized several degradable fluorene- and carbazole-based copolymers for selective extraction of s-SWCNTs. The copolymers are interlinked by imine bonds, and thus, the cleavage can be easily accomplished by acid treatment. The polymer/SWCNT complex dispersions were prepared with as-produced HiPco SWCNTs in toluene and characterized with absorption, photoluminescence excitation and emission mapping, and Raman spectroscopy. Among the synthesized polyimines, fluorene-carbazole copolymers show extremely high separation yield toward s-SWCNTs and high separation purity, while the fluorene–fluorene and fluorene-p-phenylene copolymers show lower yield but higher selectivity to s-SWCNT with specific pairs of (n,m) indices. Quantitative removal of the polymer after acid-triggered degradation was confirmed by X-ray photoelectron spectroscopy. Moreover, the released dispersant-free s-SWCNTs can be further rewrapped by different polymers. Our results pave the way toward the use of dispersant-free semiconducting carbon nanotubes (CNTs) to develop the next generation of CNT devices.

We have used a surface-science-based, ion-beam-soft-landing approach to study the heterogeneous oxidation of a series of large polycyclic aromatic hydrocarbons (PAHs) deposited onto highly oriented pyrolytic graphite (HOPG). The reactivities of well-defined thin films of hexabenzocoronene (C42H18), pentacene (C22H14), fullerene precursor (C60H30), and rubrene (C42H28) with effusive beams of oxygen atoms were compared to the reaction outcome upon depositing a monolayer of the same PAHs onto a preoxidized graphite surface. In both cases, sublimable oxidized derivatives of PAHs were observed using mass-resolved temperature-programmed desorption (with compositions assigned using oxygen isotope labeling where necessary). For all PAHs investigated, the on-top oxidation of multilayers leads to epoxides. By contrast, the products of the oxidation of (sub)monolayers are seen to depend on the molecular structure of the PAH. While the flatly adsorbing planar PAHs react to form lactones and quinones, the highly nonplanar rubrene does not show analogous surface-mediated chemistry, instead forming epoxides exclusively. These observations when taken together with our previous study of coronene oxidation are of potential interest for sp2-nanocarbon-based oxidation catalysis. Furthermore, we have demonstrated a ultra high vacuum (UHV)-based route to sublimable oxides ranging in size up to C60H30O5, which may be useful for nanotechnological applications.

We present a study of the structural evolution of tantalum cluster anions Tan-, 6 ≤ n ≤ 13 using a combination of trapped ion electron diffraction (TIED) experiments with a variety of electronic structure methods. A genetic algorithm has been employed to establish a set of likely structures for each cluster, their geometries and energetics have been studied by density functional theory (DFT), random phase approximation, and two-component (2C) DFT methods, which include spin-orbit coupling. We find octahedral structures for Ta6- and Ta8- as well as structures based on the pentagonal bipyramid (Ta7- and Ta9-). Ta10--Ta12- are defective icosahedral structures and Ta13- is a distorted icosahedron. For most clusters, we find a good agreement between the theoretically predicted ground-state structures, especially those determined by the 2C method and the TIED results.

Helical wrapping by conjugated polymer has been demonstrated as a powerful tool for the sorting of single-walled carbon nanotubes (SWCNTs) according to their electronic type, chiral index, and even handedness. However, a method of one-step extraction of left-handed (

The crown-ether coordination compounds ZnX$_{2}$(18-crown-6), EuX$_{2}$(18-crown-6) (X: Cl, Br, I), MnI$_{2}$(18-crown-6), Mn$_{3}$Cl$_{6}$(18-crown-6)2, Mn$_{3}$I$_{6}$(18-crown-6)$_{2}$, and Mn$_{2}$I$_{4}$(18-crown-6) are obtained by ionic-liquid-based synthesis. Whereas MX$_{2}$(18-crown-6) (M: Zn, Eu) show conventional structural motives, Mn$_{3}$Cl$_{6}$(18-crown-6)$_{2}$, Mn$_{3}$I$_{6}$(18-crown-6)$_{2}$, and Mn$_{2}$I$_{4}$(18-crown-6) exhibit unusual single MnX$_{4}$ tetrahedra coordinated to the crown-ether complex. Surprisingly, some compounds show outstanding photoluminescence. Thus, rare Zn$^{2+}$-based luminescence is observed and unexpectedly efficient for ZnI$_{2}$(18-crown-6) with a quantum yield of 54%. Unprecedented quantum yields are also observed for Mn$_{3}$I$_{6}$(18-crown-6)$_{2}$, EuBr$_{2}$(18-crown-6), and EuI$_{2}$(18-crown-6) with values of 98, 72, and 82%, respectively, which can be rationalized based on the specific structural features. Most remarkable, however, is Mn$_{2}$I$_{4}$(18-crown-6). Its specific structural features with finite sensitizer–activator couples result in an extremely strong emission with an outstanding quantum yield of 100%. Consistent with its structural features, moreover, anisotropic angle-dependent emission under polarized light and nonlinear optical (NLO) effects occur, including second-harmonic generation (SHG). The title compounds and their optical properties are characterized by single-crystal structure analysis, X-ray powder diffraction, chemical analysis, density functional theory (DFT) calculations, and advanced spectroscopic methods.

A selective synthesis of bi- and trinuclear complexes featuring a tetradentate monoanionic PNNP ligand is presented. The binuclear coinage metal complexes show a typical fourfold coordination for Cu and Ag, which changes to a bifold coordination for Au. The latter is accompanied by an unusual charge separation. Optical properties are investigated using photoluminescence spectroscopy and complemented by time-dependent density-functional-theory calculations. All compounds demonstrate clearly distinguished features dependent on the metals chosen and differences in the complex scaffold.

We present a straightforward and generally applicable synthesis route for cofacially linked homo‐ and heterobimetallic porphyrin complexes. The protocol allows the synthesis of unsymmetrical aryl‐based meso‐meso as well as β‐meso‐linked porphyrins. Our method significantly increases the overall yield for the published compound known as o‐phenylene‐bisporphyrin (OBBP) by a factor of 6.8. Besides the synthesis of 16 novel homobimetallic complexes containing MnIII, FeIII, NiII, CuII, ZnII, and PdII, we achieved the first single‐crystal X‐ray structure of an unsymmetrical cofacial benzene‐linked porphyrin dimer containing both planar‐chiral enantiomers of a NiII 2 complex. Additionally, this new methodology allows access to heterobimetallic complexes such as the FeIII‐NiII containing carbon monoxide dehydrogenase active site analogue. The isolated species were investigated by various techniques, including ion mobility spectrometry, DFT calculations, and UV/Vis spectroscopy. This allowed us to probe the influence of interplane distance on Soret band splitting., Simple route to dimeric complexes: Three different types of covalently linked metalloporphyrin dimers were synthesized. The monomers were synthesized sequentially and can be filled with metals before linking. As a result, different heterobimetallic systems can be made. Depending on the metals M1 and M2 used (M=Mn, Fe, Ni, Cu, Zn, Pd), a wide range of potentially catalytically active species can be prepared, such as analogues of carbon monoxide dehydrogenase.

Reaction of the PNNP ligand system N,N���-bis[(2-diphenylphosphino)phenyl]formamidinate (dpfam) featuring different coordination compartments with [AuCl(tht)], [CuMes]$_{5}$, [AgMes]$_{4}$, or [AuC$_{6}$F$_{5}$(tht)] (tht = tetrahydrothiophene) resulted in tetranuclear homo- and heterometallic coinage metal complexes, as well as a hexanuclear gold complex. All of them feature a metal string conformation. Photophysical investigation revealed a significant dependence of the photoluminescence properties on the metal composition. Below 100 K, the PL efficiency of three compounds approaches nearly 100%.

There are only a few examples of atomically precise, ligand protected, bimetallic coinage metal clusters in which molecular structure remains essentially unchanged over a wide composition range starting from the corresponding homometallic species. Such model systems are particularly useful to study the dynamics of alloy formation on the nanoscale. Here we demonstrate the unusual reactivity of solvated metalloid-superatom Ag29(BDT)12(PPh3)4 (BDT = 1,3 benzenedithiol) clusters toward semiconducting Cu12S6(DPPPT)4 (DPPPT = bis(diphenylphosphino)pentane) clusters as an efficient way to exchange multiple copper atoms into the atomically precise silver clusters without changing overall the structure type. Concentration-dependent UV-vis absorption and online mass spectrometry shows that 14 Cu atoms can be exchanged into the silver cluster. Beyond the 14 Cu atom exchange, the cluster degrades to smaller thiolates. Information on cluster structures is obtained from high-resolution ion mobility mass spectrometry, which shows a linear decrease in collision cross section (CCS) with each Ag/Cu exchanged. Several isomeric structures are calculated by density functional theory (DFT), and their calculated collision cross sections are used to identify the most stable isomers for each Ag/Cu exchange product. Ag/Cu exchange is essentially limited to the cluster surface/shell. The core appears not to be involved.

We present a study of the structural effects of hydrogen adsorption on Ru14– investigated by a combination of trapped ion electron diffraction and density functional computations. While the bare Ru...

The photophysics of the isolated trianion Ag29(BDT)123– (BDT = benzenedithiolate), a ligand-protected cluster comprising BDT-based ligands, terminating a shell of silver thiolates and a core of sil...

We report the first vibrationally well-resolved absorption and laser-induced fluorescence spectra of the radical cations of free-base phthalocyanine (H

Probing electrofluorochromism (EFC) at the molecular level remains challenging. Here we study the strongly charge state-dependent photoluminescence of vanadyl phthalocyanine. We report vibrationally resolved absorption and laser-induced fluorescence (LIF) spectra of samples comprising both the mass-selected neutral molecule (VOPc⋅, a stable radical) and its cation produced upon electron ionization (EI) isolated in 5 K neon matrices. Ionization of the essentially non-emissive VOPc⋅ forms a high-spin diradical cation (VOPc

Single-walled carbon nanotubes as emerging quantum-light sources may fill a technological gap in silicon photonics due to their potential use as near-infrared, electrically driven, classical or nonclassical emitters. Unlike in photoluminescence, where nanotubes are excited with light, electrical excitation of single tubes is challenging and heavily influenced by device fabrication, architecture, and biasing conditions. Here we present electroluminescence spectroscopy data of ultra-short-channel devices made from (9,8) carbon nanotubes emitting in the telecom band. Emissions are stable under current biasing, and no enhanced suppression is observed down to 10 nm gap size. Low-temperature electroluminescence spectroscopy data also reported exhibit cold emission and line widths down to 2 meV at 4 K. Electroluminescence excitation maps give evidence that carrier recombination is the mechanism for light generation in short channels. Excitonic and trionic emissions can be switched on and off by gate voltage, and corresponding emission efficiency maps were compiled. Insights are gained into the influence of acoustic phonons on the line width, absence of intensity saturation and exciton-exciton annihilation, environmental effects such as dielectric screening and strain on the emission wavelength, and conditions to suppress hysteresis and establish optimum operation conditions.

Although single-crystal X-ray diffraction is a proven technique to determine the structure of monolayer-protected coinage metal clusters in solid state, it is not readily applicable to the characte...

A new imino-pyridine-NHC (NHC = N-heterocyclic carbene) hybrid ligand was accessed through a multistep synthesis, and its coordination chemistry was examined among coinage metals. Mononuclear coppe...

A series of cationic molecular fragments (Cn+, n = 11, 12, 15, 16, 18, and 21), produced by electron-impact ionization of C60 in the gas phase, were each mass-selected and accumulated in cryogenic Ne matrices. Optical absorption measurements in the UV–vis and IR spectral ranges reveal linear carbon chain structures. In particular, we have observed the known electronic transitions of linear C11, C15, and C21. The NIR transitions of linear C15–, C16–, and C18– have also been detected, indicating that soft-landing of the corresponding cations can also involve charge-changing. Newly observed electronic absorptions at 410.3 and 429.9 nm have been assigned to linear C18 absorptions at 438.2, 443.5, 422.3, and 433.7 nm, to linear C15+, and absorption at 395.5 nm, to linear C16. Increasing deposition energy leads to fragmentation upon impact. This is indicated by absorptions of C10 (313, 316.3 nm), when depositing Cn+ (n = 11, 15, 16) as well as C12 (332 nm) or C14 (347.4, 356.6 nm), when depositing C15+ or C16+,...

Bis(acetylido) aurates(I) and thallium(I) trifluoromethylsulfonates were used to synthesize AuI -TlI metallopolymers, displaying novel and unusual structural motifs of the metal-metal backbones in the solid state: a discrete molecular cluster, 1D chains of interconnected dimers, tetramers, or dodecamers of Au-Tl units, and a 2D-plane network, consisting of alternating edge-linked (AuTl)6 and (AuTl)4 cycles. The formation of the different architectures was primarily controlled by the steric demand of the acetylide-substituent groups. Thus, the bulkiest 2,6-diisopropylphenyl derivative yielded a molecular cluster [Tl2 Au3 ]. Most compounds showed bright visible photoluminescence with quantum yields of up to 25 % at ambient temperature. The color of the emitted light significantly differs with the network structure. Furthermore, theoretical studies of singlet excitations in the molecular cluster, as well as NMR and mass-spectrometric investigations of the fragmentation of the metallopolymers in solution are described in detail.

The length of a carbon nanotube is an important dimension that has to be adjusted to the requirements of an experiment or application, e.g., through sorting methods. So far, atomic force microscopy (AFM) has been the method of choice for measuring length distributions, despite being an ex situ method with apparent shortcomings. In this work, we explore analytical ultracentrifugation (AUC) as an in situ method for measuring the length distribution of polymer-wrapped (7, 5) single-walled carbon nanotubes dispersed in toluene. This is an AUC study of nanotubes in nonaqueous media, the preferred media for nanotubes used in device fabrication. In AUC, the temporally and spatially dependent change in optical absorption of a sample is measured under centrifugation. The resulting sedimentation curves can be deconvoluted with a standard data processing procedure (SEDFIT), to yield the sedimentation coefficient distribution. However, the conversion of the sedimentation coefficient distribution into a length distribution is nontrivial and requires finding a suitable model for the nanotube friction coefficient. Also, since AUC is based on optical absorption, it yields a volume distribution and not a number distribution as obtained from AFM reference data. By meeting these challenges and finding a surprisingly simple empirical flexible-chain-like model to describe the sedimentation behavior of one specific chiral structure, we suggest AUC as a viable method for measuring in situ nanotube length distributions of nonaqueous dispersions.

Low energy ion beam deposition of mass-selected fullerene ions was used to generate thin films of non-IPR fullerenes, C2n (2n = 48–58 and 52–68) on graphite under UHV. These were probed by mass-resolved thermal desorption spectroscopy. We observe the emission of dimers in addition to dominant monomer desorption for 2n = 58–68, while for 2n = 48–56 no dimer desorption was detected. Dimer signals were typically at

We report the binding geometries of the isomers that are formed when the hydrogen oxalate ((CO2)2H=HOx) anion attaches to dinuclear coinage metal phosphine complexes of the form [M1M2dcpm2(HOx)]+ with M=Cu, Ag and dcpm=bis(dicyclohexylphosphino)methane, abbreviated [MM]+ . These structures are established by comparison of isomer‐selective experimental vibrational band patterns displayed by the cryogenically cooled and N2‐tagged cations with DFT calculations of the predicted spectra for various local minima. Two isomeric classes are identified that feature either attachment of the carboxylate oxygen atoms to the two metal centers (end‐on docking) or attachment of oxygen atoms on different carbon atoms asymmetrically to the metal ions (side‐on docking). Within each class, there are additional isomeric variations according to the orientation of the OH group. This behavior indicates that HOx undergoes strong and directional coordination to [CuCu]+ but adopts a more flexible coordination to [AgAg]+ . Infrared spectra of the bare ions, fragmentation thresholds and ion mobility measurements are reported to explore the behaviors of the complexes at ambient temperature., To characterize the binding motifs of hydrogen oxalate (HOx) onto copper (Cu) and silver (Ag) phosphine complexes, we have invastigated [M1M2dcpm2(HOx)]+ (M=Cu, Ag; dcpm=bis(dicyclohexylphosphino)methane; abbreviated [CuCu]+ and [AgAg]+ ) in isolation. The 40 K N2 tagged IR‐PD spectra gives evidence for two isomers of [CuCu]+ and three isomers of [AgAg]+ , supported by DFT calculations. Two color IR‐IR hole burning experiments indicate some minor amount of isomeric interconversions in [AgAg]+ , whereas [CuCu]+ reveals a stiffer HOx coordination.

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

The synthesis of copper and zinc complexes of four variably substituted iminophosphonamide ligands is presented. While the copper complexes form ligand‐bridged dimers, the zinc compounds are monomeric. Due to different steric demand of the ligand the arrangement of the ligands within the dimeric complexes varies. Similar to the structurally related iminophosphonamide complexes of alkali metals and calcium, the steady‐state and time‐resolved photoluminescence (PL) of four of the seven compounds studied here as solids in a temperature range of 5–295 K can be described within the scheme of thermally activated delayed fluorescence (TADF). Accordingly, they exhibit bright blue‐green phosphorescence at low temperatures (, To glow or not to glow: Chiral iminophosphonamide copper and zinc complexes are presented. Some steady‐state and time‐resolved photoluminescence (PL) features studied at low temperatures can be described within the thermally activated delayed fluorescence (TADF) scheme. However, unusually, the fluorescence is nearly absent in two complexes and the low‐lying triplet state quenches PL. Some excited states were further investigated by time‐resolved FTIR spectroscopy and quantum chemical calculations.

The original article has been corrected.

The modular synthesis of Au(I)/Ru(II) decorated mono‐ and heterobimetallic complexes with π‐conjugated [2.2]paracyclophane is described. [2.2]Paracyclophane serves as a rigid spacer which holds the metal centers in precise spatial orientations and allows metal‐to‐metal distance modulation. A broad set of architectural arrangements of pseudo ‐geminal, ‐ortho, ‐meta, and ‐para substitution patterns were employed. Metal‐to‐metal distance modulation of Au(I)/Ru(II) heterobimetallic complexes and the innate transannular π‐communication of the cyclophanyl scaffold provides a promising platform for the investigations of structure‐activity relationship and cooperative effects. The Au(I)/Ru(II) heterobimetallic cyclophanyl complexes are stable, easily accessible, and exhibit promising catalytic activity in the visible‐light promoted arylative Meyer‐Schuster rearrangement., M‐to‐M Distance Modulation: Au(I)/Ru(II) decorated mono‐ and distance‐modulated heterobimetallic complexes featuring co‐facially stacked π‐conjugated [2.2]paracyclophanes as rigid spacer are synthesized. Employing a broad set of architectural arrangements of cyclophanyl‐derived pseudo‐geminal, ‐ortho, ‐meta, and ‐para substitution patterns, enables metal‐to‐metal distance modulation with defined spatial orientation of the Au(I)/Ru(II) metal centers. The Au(I)/Ru(II) heterobimetallic complexes with varying metal‐to‐metal distances provide a promising platform for the investigation of structure, property, and reactivity relation in cooperative effects.

The synthesis of calcium complexes ligated by three different chiral iminophosphonamide ligands, L‐H (L=[Ph2P{N(R)CH(CH3)Ph}2]), L′‐H (L′=[Ph2P{NDipp}{N(R)CH(CH3)Ph}]), (Dipp=2,6‐iPr2C6H3), and L′′‐H (L′′=[Ph2P{N(R)CH(CH3)naph}2]), (naph=naphthyl) is presented. The resulting structures [L 2Ca], [L′ 2Ca], and [L′′ 2Ca] represent the first examples of enantiopure homoleptic calcium complexes based on this type of ligands. The calcium complexes show blue–green photoluminescence (PL) in the solid state, which is especially bright at low temperatures. Whereas the emission of [L′′ 2Ca] is assigned to the fluorescence of naphthyl groups, the PL of [L 2Ca] and [L′ 2Ca] is contributed by long‐lived phosphorescence and thermally activated delayed fluorescence (TADF), with a strong variation of the PL lifetimes over the temperature range of 5–295 K. Furthermore, an excellent catalytic activity was found for these complexes in hydroboration of ketones at room temperature, although no enantioselectivity was achieved., Glowing bones: Enantiopure homoleptic iminophosphonamide calcium complexes have been prepared. These show rich photoluminescence properties and catalytic activity in the hydroboration of ketones.

Dielectrophoresis (DEP) describes the motion of suspended objects when exposed to an inhomogeneous electric field. It has been successful as a method for parallel and site-selective assembling of nanotubes from a dispersion into a sophisticated device architecture. Researchers have conducted extensive works to understand the DEP of nanotubes in aqueous ionic surfactant solutions. However, only recently, DEP was applied to polymer-wrapped single-walled carbon nanotubes (SWCNTs) in organic solvents due to the availability of ultra-pure SWCNT content. In this paper, the focus is on the difference between the DEP in aqueous and organic solutions. It starts with an introduction into the DEP of carbon nanotubes (CNT-DEP) to provide a comprehensive, in-depth theoretical background before discussing in detail the experimental procedures and conditions. For academic interests, this work focuses on the CNT-DEP deposition scheme, discusses the importance of the electrical double layer, and employs finite element simulations to optimize CNT-DEP deposition condition with respect to the experimental observation. An important outcome is an understanding of why DEP in organic solvents allows for the deposition and alignment of SWCNTs in low-frequency and even static electric fields, and why the response of semiconducting SWCNTs (s-SWCNTs) is strongly enhanced in non-conducting, weakly polarizable media. Strategies to further improve CNT-DEP for s-SWCNT-relevant applications are given as well. Overall, this work should serve as a practical guideline to select the appropriate setting for effective CNT DEPs.

We have studied the capability of He

Two-dimensional (2D) layered hybrid bromoplumbate perovskites are promising candidates for solution-processed light-emitting materials. Here, we report the synthesis and characterization of two novel layered bromoplumbates: (4BrPhMA)(2)PbBr4 (1) and (4BrPhA)(6)Pb3Br12 (2), where 4BrPhMA is (4-bromophenyl)methylammonium and 4BrPhA is (4-bromophenyl) ammonium. Despite similar optical absorption, these materials show remarkably different photoluminescence properties: 1 emits a narrow exciton band at ca. 395 nm with a very small bandwidth (particularly at low temperatures of 1550 K) and Stokes shift, while 2 exhibits a broad emission at ca. 560 nm with a large Stokes shift, both at low and ambient temperatures. However, under several kbar of hydrostatic pressure, the broad emission diminishes and a new band reversibly develops at ca. 395 nm, similar to that in 1. Our results emphasize organic layer flexibility as an important design factor for this class of perovskite-like materials featuring broadband emission.

We report the synthesis and catalytic application of a highly stable distance-defined Au/Ru heterobimetallic complex. [2.2]Paracyclophane serves as a backbone, holding the two metal centers in a spatial orientation and metal-metal fixed distance. The Au/Ru heterobimetallic complex is highly stable, easily accessible and exhibits promising catalytic activity in a visible-light mediated dual Au/Ru Meyer-Schuster rearrangement.

The enantiomerically pure ligand P,P-diphenyl-N,N′-bis((R)-1-phenylethyl)phosphinimidic amide (1; (R)-HPEPIA) was synthesized and subsequently deprotonated with alkali metal precursors to yield dimeric complexes [M2{(R)-PEPIA}2] (M = Li (2), Na (3), K (4), Rb (5)). The cesium compound [M{(R)-PEPIA}] (6) crystallized as a cocrystal composed of dimeric ([Cs2{(R)-PEPIA}2] (6d) and 1D-polymeric ([Cs{(R)-PEPIA}]n) (6p) species in a 1 : 1 ratio. The coordination polymer 6p features a unique sinus-shaped configuration of repeating –Cs–N–P–N–Cs–N–P–N– units. Unusual photoluminescence (PL) properties were found for solid 1–6: in contrast to the fluorescent ligand 1, the alkali metal complexes show phosphorescence at low temperatures (

The photophysics of the isolated trianion Ag