We report the development of a new high-flux electrospray ionization-based instrument for soft landing of mass-selected fragment ions onto surfaces. Collision-induced dissociation is performed in a collision cell positioned after the dual electrodynamic ion funnel assembly. The high duty cycle of the instrument enables high-coverage deposition of mass-selected fragment ions onto surfaces at a defined kinetic energy. This capability facilitates the investigation of the reactivity of gaseous fragment ions in the condensed phase. We demonstrate that the observed reactions of deposited fragment ions are dependent on the structure of the ion and the composition of either ionic or neutral species codeposited onto a surface. The newly developed instrument provides access to high-purity ion fragments as building blocks for the preparation of unique ionic layers.

Electrophilic anions of type [B 12 X 11 ] À posses a vacant positive boron binding site within the anion. In a comparatitve experimental and theoretical study, the reactivity of [B 12 X 11 ] À with X=F, Cl, Br, I, CN is characterized towards different nucleophiles: (i) noble gases (NGs) as σ-donors and (ii) CO/N 2 as σ-donor-π-acceptors. Temperature-dependent formation of [B 12 X 11 NG] À indicates the enthalpy order (X=CN) > (X=Cl) � (X=Br) > (X=I) � (X=F) almost independent of the NG in good agreement with calculated trends. The observed order is explained by an interplay of the electron deficiency of the vacant boron site in [B 12 X 11 ] À and steric effects. The binding of CO and N 2 to [B 12 X 11 ] À is significantly stronger. The B3LYP 0 K attachment enthapies follow the order (X=F) > (X=CN) > (X=Cl) > (X=Br) > (X=I), in contrast to the NG series. The bonding motifs of [B 12 X 11 CO] À and [B 12 X 11 N 2 ] À were characterized using cryogenic ion trap vibrational spectroscopy by focusing on the CO and N 2 stretching frequencies n CO and n N 2 , respectively. Observed shifts of n CO and n N 2 are explained by an interplay between electrostatic effects (blue shift), due to the positive partial charge, and by π-backdonation (red shift). Energy decomposition analysis and analysis of natural orbitals for chemical valence support all conclusions based on the experimental results. This establishes a rational understanding of [B 12 X 11 ] À reactivety dependent on the substituent X and provides first systematic data on π-backdonation from delocalized σ-electron systems of closo-borate anions.

The highly reactive gaseous ion [B12Br11]– is a metal-free closed-shell anion which spontaneously forms covalent bonds with hydrocarbon molecules, including alkanes. Herein, we systematically investigate the reaction mechanism for binding...

Nitro-functionalized undecahalogenated closo-dodecaborates [B 12 X 11 (NO 2)] 2À were synthesized in high purities and characterized by NMR, IR, and Ramans pectroscopy, single crystal X-diffraction, mass spectrometry,a nd gasphase ion vibrational spectroscopy.T he NO 2 substituent leads to an enhanced electronic and electrochemical stability compared to the parent perhalogenated [B 12 X 12 ] 2À (X = F-I) dianions evidenced by photoelectron spectroscopy,c yclic voltammetry,a nd quantum-chemical calculations. The stabilizing effect decreasesf rom X = Ft oX= I. Thermogravimetric measurementso ft he salts indicate the loss of the nitric oxide radical(NOC). The homolytic NOC eliminationf rom the dianion under very soft collisionale xcitation in gas-phase ion experiments results in the formation of the radical [B 12 X 11 O] 2À C.T heoretical investigations suggest that the loss of NOC proceeds via the rearrangementp roduct [B 12 X 11 (ONO)] 2À .T he O-bonded nitrosooxy structure is thermodynamically more stable than the N-bonded nitro structure and its formationb yr adicalr ecombination of [B 12 X 11 O] 2À C andN OC is demonstrated.

We investigate collision-induced dissociation (CID) of [Mo6X14]2– (X = Cl, Br, I) and the reactivity of fragment ions of these precursors with background gases. Ion mobility measurements and theoretical calculations provide structural information for some of the observed ions. Sequential losses of MoX2 units dominate the dissociation pathways of [Mo6Cl14]2–. Meanwhile, loss of X radicals is the main channel for X = Br and I. Ion mobility measurements and computational investigations indicate minor structural changes in the octahedral Mo6 unit for [Mo6I m ]− (m = 6–13) fragments. We observe that mass spectra obtained using CID substantially vary among mass spectrometers: Specifically, ions with molecular formula [Mo6X m (O2) n ]− (X = Br and I) are observed as dominant species produced through reactions with O2 in several mass spectrometers, but also adduct free fragment ions were observed in other instruments, depending on the background conditions. Ion-trap fragmentation combined with theoretical investigations indicates that spontaneous losses of X radicals occur upon binding of O2 to [Mo6I m ]− fragments (m ≤ 12). Theoretical investigations indicate that both oxygen atoms are bound to the vacant sites of the Mo6 units. This study opens up a new vista to generate and study a large variety of hexanuclear Mo6X m (O2) n anions.

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The new closo‐dodecaborates [B12X11(NO2)]2− (X=halogen) were synthesized in high yields and fully characterized by structural and spectroscopic methods. The artwork illustrates its remarkable electronic and chemical stability. However, thermally it easily cleaves off an NO radical. The resulting double negatively charged radical [B12X11O]2−. is highly reactive and can recombine with NO in the gas phase to the even more stable unprecedented [B12X11(ONO)]2− anions. More information can be found in the Full Paper by C. Jenne, J. Warneke, et al. on page 14594.

The vibrational frequency of CO, which binds to different electrophilic anions [B12X11]‐ (X=F, Cl, Br, I), is determined by an interplay of blue‐shifting electrostatics (blue beam between boron and carbon) and red shifting π‐backdonation (flames). For X=Cl, Br, I, (upper half) electrostatics dominates, while for X=F (bottom) π‐backdonation dominates and binds CO exceptionally strongly. Measured spectra are shown on the right. The band of unbound CO would be found at the position of the laser beam. More information can be found in the Full Paper by M. Mayer, J. Warneke, et al. (DOI: 10.1002/chem.202100949).