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Gas‐phase investigations on acetone, under the influence of electric pulsed discharge has provided distinct insight related to its decomposition. Time‐of‐flight mass spectrometry has been utilized to identify different products generated upon dissociation/ionization of acetone, under the influence of electric discharge. In addition to molecular (C3H6O+) and protonated acetone (C3H7O+) ions, predominant ions signal corresponding to C3H4O+, C3O+ and CH3CO+ were observed in the mass spectrum. Under discharge condition, acetone undergoes soft dissociation/ionization producing C3H4O+ and C3O+ ions, which are distinctive from usual fragment ions reported upon decomposition of acetone, in the gas‐phase. Though metastable in nature, significant ion yield has been obtained for C3O+ ions. Computational studies have been carried out to understand the mechanism of acetone decomposition in gas‐phase. Based on experimental and computational findings, generation of these ions (C3O+ and C3H4O+) has been ascribed to step‐wise H2 elimination reaction originating from acetone molecule, followed by ionization of resultant fragments under the influence of electric pulsed discharge. Present studies are of relevance for plasma pyrolysis of volatile organic compounds and laboratory astrochemical investigations. [ABSTRACT FROM AUTHOR]

Actinyl chemistry is extended beyond Cm to BkO2+ and CfO2+ through transfer of an O atom from NO2 to BkO+ or CfO+ , establishing a surprisingly high lower limit of 73 kcal mol-1 for the dissociation energies, D[O-(BkO+ )] and D[O-(CfO+ )]. CCSD(T) computations are in accord with the observed reactions, and characterize the newly observed dioxide ions as linear pentavalent actinyls; these being the first Bk and Cf species with oxidation states above IV. Computations of actinide dioxide cations AnO2+ for An=Pa to Lr reveal an unexpected minimum for D[O-(CmO+ )]. For CmO2+ , and AnO2+ beyond EsO2+ , the most stable structure has side-on bonded η2 -(O2 ), as AnIII peroxides for An=Cm and Lr, and as AnII superoxides for An=Fm, Md, and No. It is predicted that the most stable structure of EsO2+ is linear [O=EsV =O]+ , einsteinyl, and that FmO2+ and MdO2+ , like CmO2+ , also have actinyl(V) structures as local energy minima. The results expand actinide oxidation state chemistry, the realm of the distinctive actinyl moiety, and the non-periodic character towards the end of the periodic table.

Abstract A gas‐phase investigation of the D‐fructose dehydration reaction in the presence of base has been performed by the joint application of mass spectrometric techniques and theoretical calculations. Protonated addition products of D‐fructose and base were generated in the gas phase by electrospray ionization using several bases of different proton affinity. The intermediates, products and decomposition channels were investigated by ion trap mass spectrometry. Electronic structure calculations allowed the identification of the ionic intermediates and products of a selected system containing NH3, helping to rationalize the observed reaction pathways. The obtained results show that the final product, the protonated 5‐hydroxymethyl‐2‐furaldheyde [5‐HMF]H+, is better formed using selected bases and only if these remain clustered until the end of the dehydration process.

A gas‐phase investigation of the D‐fructose dehydration reaction in the presence of base has been performed by the joint application of mass spectrometric techniques and theoretical calculations. Protonated addition products of D‐fructose and base were generated in the gas phase by electrospray ionization using several bases of different proton affinity. The intermediates, products and decomposition channels were investigated by ion trap mass spectrometry. Electronic structure calculations allowed the identification of the ionic intermediates and products of a selected system containing NH3, helping to rationalize the observed reaction pathways. The obtained results show that the final product, the protonated 5‐hydroxymethyl‐2‐furaldheyde [5‐HMF]H+, is better formed using selected bases and only if these remain clustered until the end of the dehydration process. [ABSTRACT FROM AUTHOR]

Unexpectedly, the 5‐dehydroquinoline radical cation was formed in the gas phase from the 5‐iodo‐8‐nitroquinolinium cation upon ion‐trap collision‐activated dissociation. This reaction involves the cleavage of a nitro group to generate an intermediate monoradical, namely, the 8‐dehydro‐5‐iodoquinolinium cation, followed by rearrangement through abstraction of a hydrogen atom from the protonated nitrogen atom by the radical site. Dissociation of the rearranged radical cation through elimination of an iodine atom generates the 5‐dehydroquinoline radical cation. The mechanism was probed by studying isomeric biradicals and performing quantum chemical calculations. The 5‐dehydroquinoline radical cation showed greater gas‐phase reactivity toward dimethyl disulfide, cyclohexane, and allyl iodide than the isomeric 5,8‐didehydroquinolinium cation, which is more reactive than the isomeric 5,8‐didehydroisoquinolinium cation studied previously. All three isomers have a 1,4‐biradical topology. The order of reactivity is rationalized by the vertical electron affinities of the radical sites of these biradicals instead of their widely differing singlet–triplet splittings. [ABSTRACT FROM AUTHOR]

3‐Bromopyruvic acid (3BP) is a potential anti‐cancer drug, the action of which on cellular metabolism is not yet entirely clear. The presence of a bromine atom suggests that it is also reactive towards low‐energy electrons, which are produced in large quantities during tumour radiation therapy. Detailed knowledge of the interaction of 3BP with secondary electrons is a prerequisite to gain a complete picture of the effects of 3BP in different forms of cancer therapy. Herein, dissociative electron attachment (DEA) to 3BP in the gas phase has been studied both experimentally by using a crossed‐beam setup and theoretically through scattering and quantum chemical calculations. These results are complemented by a vacuum ultraviolet absorption spectrum. The main fragmentation channel is the formation of Br− close to 0 eV and within several resonant features at 1.9 and 3–8 eV. At low electron energies, Br− formation proceeds through σ* and π* shape resonances, and at higher energies through core‐excited resonances. It is found that the electron‐capture cross‐section is clearly increased compared with that of non‐brominated pyruvic acid, but, at the same time, fragmentation reactions through DEA are significantly altered as well. The 3BP transient negative ion is subject to a lower number of fragmentation reactions than those of pyruvic acid, which indicates that 3BP could indeed act by modifying the electron‐transport chains within oxidative phosphorylation. It could also act as a radio‐sensitiser. Deeper dissociation: The brominated analogue of pyruvic acid, which is the main product of glycolysis, 3‐bromopyruvic acid (3BP), is a potential anti‐cancer and strongly alkylating agent. Herein, dissociative electron attachment to 3BP in the gas phase has been studied experimentally and theoretically to reveal that 3BP could indeed act by modifying the electron‐transport chains within oxidative phosphorylation (see figure). [ABSTRACT FROM AUTHOR]

Abstract: Translating a homogenous catalyst into a heterogeneous catalyst requires a fundamental understanding of how the catalyst “fits” into the zeolite and how the reaction is influenced. Previous studies of bimetallic catalyst design identified a potent copper homobinuclear catalyst, [(L)Cu2(H)]+ for the selective decomposition of formic acid. Here, a close interplay between theory and experiment shows how to preserve this selective reactivity within zeolites. Gas‐phase experiments and DFT calculations showed that switching from 1,1‐bis(diphenylphosphino)‐methane ligand to the 1,8‐naphthyridine ligand produced an equally potent catalyst. DFT calculations show that this new catalyst neatly fits into a zeolite which does not perturb reactivity, thus providing a unique example on how “heterogenization” of a homogenous catalyst for the selective catalysed extrusion of carbon dioxide from formic acid can be achieved, with important application in hydrogen storage and in situ generation of H2. [ABSTRACT FROM AUTHOR]

Abstract: The structure sensitivity of Pt nanoparticles (PtN) for gas‐phase acrolein (AC) hydrogenation was probed for PtN on BaxSr1−xTiO3 nanocuboid supports with (0 0 1) facets in a combined theoretical and experimental study. The in situ selectivity for allyl alcohol increased with the increase of the Sr concentration in the support, which corresponds to modifications in the stable Winterbottom shape and lattice strain of the Pt nanoparticles as a result of the interfacial energy between Pt and the BaxSr1−xTiO3 supports. “Local model” nanofacets of the Pt surface, edge, and corner morphologies were developed as compact representations of adsorption and reaction sites. DFT was used as the primary modeling tool for the equilibrium adsorption states. We argue that adsorption on edge sites is critically important for the overall allyl alcohol selectivity of PtN catalysts. A simple model was developed to represent PtN strain effects caused by its interaction with the substrate. Bader topological atom, spherical volume averaging charge, and modified bond valence sum analyses were used to understand the bonding structure. Density of states analysis was performed for the structures of PtN, adsorbed AC, and intermediate products to examine adsorbate–particle interactions. The simulated hydrogenation of AC on PtN nanofacets was compared to the in situ hydrogenation of AC by PtN on BaxSr1−xTiO3 to examine the effects of facet, edge, and corner sites on the overall selectivity. [ABSTRACT FROM AUTHOR]

Low-energy electrons effectively decompose the isomers 2-nitroimidazole and 4(5)-nitroimidazole by dissociative electron attachment (DEA) into a variety of fragment anions and radicals. The present study shows that a distinct selectivity for the two isomers occurs in the DEA reactions. Several new decay channels are observed for 2-nitroimidazole, including a dominant one leading to the loss of molecular H2O by attachment of a low-energy electron. In contrast, the loss of a single hydrogen atom is a much more efficient reaction in DEA to 4(5)-nitroimidazole. Quantum chemical calculations were carried out to explain the pronounced isomer effect found in the DEA experiment. Although the free energies of the reactions are similar for the different isomers, the very different natures of the dipole-bound states and valence-bound anions lead to preference for or hindrance of a particular dissociation channel. Nitroimidazolic compounds are considered as radiosensitizing compounds in tumor radiation therapy. The enhanced formation of fragments, including the highly reactive hydroxyl radical, in DEA to 2-nitroimidazole suggests that it may be a more efficient radiosensitizing agent than 4(5)-nitroimidazoles. [ABSTRACT FROM AUTHOR]

Molecular mechanisms for the gas-phase degradation of levoglucosan, the major intermediate in cellulose gasification, were studied by kinetic analysis at 550–700 °C (residence time: 0.11–0.45 s), and a mixed mechanism including heterolysis and radical chain reactions is suggested. Density functional theory calculations indicated that one of the cyclic Grob reactions can proceed ( E a 57.4 kcal mol −1 ), which is supported by the selective formation of acrolein and glyoxal at 500 °C. Nevertheless, contributions of these heterolytic reactions were suggested to be smaller than radical chain reactions, which would proceed via the C- and O-centered radicals. Influences of the bicyclic ring and the hydrocarbon/oxygenated gas selectivity are also discussed. These results provide insights into the upgrading of the gasification processes of cellulosic biomass. [ABSTRACT FROM AUTHOR]

Aminophosphine [Mo3S4X3(edpp)3]+ cluster complexes, 1+ (X = Cl) and 2+ (X = Br) {edpp = (2-aminoethyl)diphenylphosphine} have been quantitatively prepared by treating the [Mo3S7X6]2- anion with the edpp ligand in a one-pot synthetic procedure. Alternatively, complexes 1+ and 2+ can be synthesized using polymeric {Mo3S7X4} n phases as metal precursors. Their crystal structures show the incomplete cubane-type Mo3S4 cluster core as well as the formation of a unique isomer in which the nitrogen atoms of the amino group and the halide atoms are located above the trimetallic plane. Gas-phase reactivity studies on complexes 1+ and 2+ show the subsequent elimination of neutral HX (X = Cl, Br) molecules under collision induced dissociation (CID) conditions. The fragmentation pattern of 1+ and 2+ in combination with gas-phase DFT calculations are contrary to the general ideas involving the hemilabile character of the aminophosphine ligands and give support to the formation of unsaturated molybdenum/imine Mo=NH species. On the basis of DFT calculations, two competitive mechanisms involving a proton transfer from the amino group to a halide ligand attached to the geminal or to the vicinal molybdenum center are proposed. The first mechanism, which is a proton transfer within the nitrogen and halogen atoms bound to the same metal atom, is energetically favored from a theoretical point of view. [ABSTRACT FROM AUTHOR]

High-level electronic structure calculations, in combination with Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometric studies, permit the mechanism by which closed-shell, 'naked' [TaO2]+ brings about C−H bond activation of methane to be revealed. These studies also help to understand why the lighter congeners of [MO2]+ (M=V, Nb) are unreactive under ambient conditions. [ABSTRACT FROM AUTHOR]

The formation and investigation of sulfur-based cysteine radicals cationized by a group 1A metal ion or Ag+ in the gas phase are reported. Gas-phase ion-molecule reactions (IMR) and infrared multiple-photon dissociation (IRMPD) spectroscopy revealed that the Li+, Na+, and K+ adducts of the cysteine radical remain S-based radicals as initially formed. Theoretical calculations for the three alkali metal ions found that the lowest-energy isomers are Cα-based radicals, but they are not observed experimentally owing to the barriers associated with the hydrogen-atom transfer. A mechanism for the S-to-Cα radical rearrangement in the metal ion complexes was proposed, and the relative energies of the associated energy barriers were found to be Li+>Na+>K+ at all levels of theory. Relative to the B3LYP functional, other levels of calculation gave significantly higher barriers (by 35-40 kJ mol−1 at MP2 and 44-47 kJ mol−1 at the CCSD level) using the same basis set. Unlike the alkali metal adducts, the cysteine radical/Ag+ complex rearranged from the S-based radical to an unreactive species as indicated by IMRs and IRMPD spectroscopy. This is consistent with the Ag+/cysteine radical complex having a lower S-to-Cα radical conversion barrier, as predicted by the MP2 and CCSD levels of theory. [ABSTRACT FROM AUTHOR]

Levoglucosan, the major intermediate in wood gasification, is decomposed selectively to C1/C2 fragments at 550-600 °C. Kinetic analyses suggest that radical chain mechanisms with the involvement of short-lived carbonyl intermediates explain the lower production of larger fragments. To address this hypothesis, the gas-phase reactivities of glyceraldehyde (Gald), 1,3-dihydroxyacetone (DHA), and glycerol, as simple C3 model compounds, were compared at 400-800 °C under N2 flow at residence times of 0.9-1.4 s. Retro-aldol fragmentation and dehydration proceeded for the pyrolysis of Gald/DHA at 400 °C, far below the 600 °C decomposition point of glycerol. Pyrolysis of Gald/DHA generated exclusively syngas (CO and H2). On the basis of the results of theoretical calculations, the effects of carbonyl intermediates on reactivity were explained by postulating uni- and bimolecular reactions, although the bimolecular reactions became less effective at elevated temperatures. [ABSTRACT FROM AUTHOR]

The thermal reaction of [Ho(CH2S)]+ with toluene giving rise to [C6H5CHSHo]+ and CH4 has been investigated using Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry complemented by density functional theory (DFT) calculations. The high reactivity of [Ho(CH2S)]+ which is in distinct contrast with the non-reactivity of 'bare' Ho+ has its origin in the presence of a carbon-centered radical; the latter initiates hydrogen-atom abstraction from the methyl group of toluene as the first step of a sequence of hydrogen and sulfur transfer mediated by cationic holmium. [ABSTRACT FROM AUTHOR]

The thermal reaction of [Ho(CH2S)]+ with toluene giving rise to [C6H5CHSHo]+ and CH4 has been investigated using Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry complemented by density functional theory (DFT) calculations. The high reactivity of [Ho(CH2S)]+ which is in distinct contrast with the non-reactivity of 'bare' Ho+ has its origin in the presence of a carbon-centered radical; the latter initiates hydrogen-atom abstraction from the methyl group of toluene as the first step of a sequence of hydrogen and sulfur transfer mediated by cationic holmium. [ABSTRACT FROM AUTHOR]

Mechanistic aspects of an unusual reaction of [HoC6H4S]+ with CH3X (X=Cl, Br, I) have been investigated using Fourier-transform ion cyclotron resonance mass spectrometry combined with density functional theory (DFT) calculations. In this thermal process, all four bonds of the methyl halides are cleaved. [ABSTRACT FROM AUTHOR]

The gas-phase reactions of chlorobenzene with all atomic lanthanide cations Ln+ (except Pm+) have been investigated by using Fourier transform ion cyclotron resonance mass spectrometry in conjunction with density functional theory calculations. According to the latter, a direct chlorine transfer to the lanthanide cation, which has been observed previously for fluorine abstraction from fluorobenzene, is not operative for the C6H5Cl/Ln+ couples; rather, chlorine transfer proceeds through an initial coordination of the lanthanide cation to the aromatic ring of the substrate. Both, the product distribution and the chlorine abstraction efficiencies are affected by the bond dissociation energy (BDE(Ln+Cl)) as well as the promotion energies of Ln+ to attain a 4f n 5d1 6s1 configuration. In addition, mechanistic aspects of some CH and CC bond activations are presented. Where appropriate, comparison with the previously studied C6H5F/Ln+ systems is made. [ABSTRACT FROM AUTHOR]

The mechanism of the Pauson-Khand reaction has been studied by mass spectrometry and it has been found, through ion-molecule reaction with 13CO, that the carbon monoxide incorporated into the product cyclopentenone is one that has been retained within the complex. Theoretical and kinetic calculations support this finding, which provides a complementary explanation for the effect of Pauson-Khand promoters. [ABSTRACT FROM AUTHOR]

Molybdenum(IV) hydroxo [Mo3S4(dmpe)3(OH)3]+ ( 1+) and hydrosulfido [Mo3S4(dmpe)3(SH)3]+ ( 2+) [dmpe = 1,2-bis(dimethylphosphanyl)ethane] trimetallic cuboidal cluster complexes have been isolated in high yields by treating their chloride precursors with sodium hydroxide or sodium hydrosulfide, respectively. The crystal structures of [ 1]BPh4 and [ 2]PF6 confirm that -QH (Q = O, S) groups are coordinated to metal centers. Both hydroxo and hydrosulfido Mo3S4 cluster complexes are fully characterized by spectroscopic, mass spectrometric, and X-ray techniques. A comparative study of the gas-phase dissociation of 1+ and 2+ cations using ESI tandem mass spectrometry is presented, and the results are compared with those already reported for the hydroxo tungsten analogue. The gas-phase reactivity of 1+ and 2+ species towards ethanol and 1-penthanethiol have been explored. The gas-phase-generated [Mo3S4(dmpe)2(O)(OH)]+ cation activates ethanol molecules through a similar mechanism to that proposed for its tungsten congener. The main differences in aldehyde elimination under collision-induced dissociation (CID) conditions between molybdenum and tungsten cluster sulfides are discussed. [ABSTRACT FROM AUTHOR]

The relative gas-phase acidities of 25 ring-substituted benzoic and phenylacetic acids were theoretically determined with proton-transfer reactions. The energies and geometries of the acids and their corresponding anions, which were involved in the reactions, were calculated at the B3LYP/6-311+G(2d,p) level of theory. The obtained substituent effects were compared with each other and those of phenols. The acidities of the benzoic and phenylacetic acids were governed by three kinds of electronic effects (inductive, resonance, and saturation effects), which confirmed that the acidities were reflected in the nature of the benzoate and phenylacetate anions, respectively. Substituent effect analyses with an extended Yukawa-Tsuno equation, ${ - {\rm{\Delta }}E_X = \rho \left( {\sigma ^0 + r^ - {\rm{\Delta }}\bar \sigma _{\rm{R}}^ - + s{\rm{\Delta }}\bar \sigma _{\rm{S}} } \right)}$, gave excellent linear correlations for both anionic systems. The degrees of through-resonance and saturation effects in the phenylacetate anion, as reflected by the resultant r− and s values, were unexpectedly larger than those in the benzoate anion, which were mainly attributed to hyperconjugation and through-space interactions between the anionic moiety and the benzene π-electron system, respectively. The acidities of the benzoic acids (or stabilities of the benzoate anions) constituted a better system than the acidities of phenylacetic acids (or stabilities of the phenylacetate anions) for a standard of the normal substituent constants ( σ0) for anions in the gas phase, in contrast to solution-phase results. [ABSTRACT FROM AUTHOR]

The activation of C-halogen bonds by the SO .+ radical cation is investigated in the gas phase. The CCl bond of CH2Cl2 is activated by fast and effective chloride-ion transfer, whereas the CF bond of CH2F2 is activated by a very slow fluoride-ion transfer. In both cases, thermodynamic and kinetic factors account for the type of process and the observed selectivity, that is, carbon-halogen versus carbon-hydrogen activation, mainly owing to the presence of the sulfur atom. The cleavage of the CCl bond of CH2Cl2 by SO .+ is a rare example of a very effective and selective chloride-ion abstraction by a metal-free, sulfur-centred radical cation. [ABSTRACT FROM AUTHOR]

The gas-phase interactions between Ca2+ and cysteine (Cys) have been investigated through the use of electrospray ionization/mass spectrometry techniques and B3LYP/6-311++G(3df,2p)//B3LYP/6-311+G(d,p) density functional theory computations. The unimolecular collision-activated decomposition of [Ca(Cys)]2+ is dominated by the loss of ammonia, a Coulomb explosion yielding NH4+ and [CaC3H3O2S]+, and the loss of H2S. The detection of lighter [C3H3OS]+ monocations indicates that the [CaC3H4O2S]2+ doubly charged species produced by the loss of ammonia undergo a subsequent Coulomb explosion yielding [C3H3OS]++CaOH+. This [C3H3OS]+ cation finally decomposes into [C2H3S]++CO. Alternatively, the aforementioned [CaC3H4O2S]2+ dications may also lead to lighter [CaCO2]2+ and [CaC2H4S]2+ dications by the loss of C2H4S and CO2, respectively. A detailed theoretical exploration of the Ca2+/Cys potential-energy surface indicates that the salt-bridge structures, in which the metal dication interacts with the carboxylate group of the zwitterionic form of cysteine, are at the origin of the different reaction pathways leading to the observed product ions, even though they lie higher in energy than the charge-solvated adduct in which the metal interacts simultaneously with the carbonyl oxygen, the amino, and the SH group of its canonical form. The interaction between the metal cation and the base is essentially electrostatic, with a calculated binding energy of 560 kJ mol−1. [ABSTRACT FROM AUTHOR]

The H.-atom transfer (HAT) reaction is investigated in the gas phase, starting from two different entrance channels, O2.+/CH2X2 and CH2X2.+/O2 (X=F, Cl), that correspond to a step of hydride transfer and to HAT, respectively. Analysis of the spin and charge along the reaction pathway shows that HAT occurs through the same reacting configuration, irrespective of whether the reactants are formed within the complex or are free isolated species. [ABSTRACT FROM AUTHOR]

The H.-atom transfer (HAT) reaction is investigated in the gas phase, starting from two different entrance channels, O2.+/CH2X2 and CH2X2.+/O2 (X=F, Cl), that correspond to a step of hydride transfer and to HAT, respectively. Analysis of the spin and charge along the reaction pathway shows that HAT occurs through the same reacting configuration, irrespective of whether the reactants are formed within the complex or are free isolated species. [ABSTRACT FROM AUTHOR]

The reactivities of the adamantane-like heteronuclear vanadium-phosphorus oxygen cluster ions [V xP4− xO10].+ ( x=0, 2-4) towards hydrocarbons strongly depend on the V/P ratio of the clusters. Possible mechanisms for the gas-phase reactions of these heteronuclear cations with ethene and ethane have been elucidated by means of DFT-based calculations; homolytic CH bond activation constitutes the initial step, and for all systems the PO. unit of the clusters serves as the reactive site. More complex oxidation processes, such as oxygen-atom transfer to, or oxidative dehydrogenation of the hydrocarbons require the presence of a vanadium atom to provide the electronic prerequisites which are necessary to bring about the 2e− reduction of the cationic clusters. [ABSTRACT FROM AUTHOR]

Fragmentation of the γ-aminobutyric acid molecule (GABA, NH2(CH2)3COOH) following collisions with slow O6+ ions ( v≈0.3 a.u.) was studied in the gas phase by a combined experimental and theoretical approach. In the experiments, a multicoincidence detection method was used to deduce the charge state of the GABA molecule before fragmentation. This is essential to unambiguously unravel the different fragmentation pathways. It was found that the molecular cations resulting from the collisions hardly survive the interaction and that the main dissociation channels correspond to formation of NH2CH2+, HCNH+, CH2CH2+, and COOH+ fragments. State-of-the-art quantum chemistry calculations allow different fragmentation mechanisms to be proposed from analysis of the relevant minima and transition states on the computed potential-energy surface. For example, the weak contribution at [ M−18]+, where M is the mass of the parent ion, can be interpreted as resulting from H2O loss that follows molecular folding of the long carbon chain of the amino acid. [ABSTRACT FROM AUTHOR]

Hydrogen-atom transfer (HAT), as one of the fundamental reactions in chemistry, is investigated with state-of-the-art gas-phase experiments in conjunction with computational studies. The focus of this Minireview concerns the role that the intrinsic properties of gaseous oxo-clusters play to permit HAT reactivity from saturated hydrocarbons at ambient conditions. In addition, mechanistic implications are discussed which pertain to heterogeneous catalysis. From these combined experimental/computational studies, the crucial role of unpaired spin density at the abstracting atom becomes clear, in distinct contrast to recent conclusions derived from solution-phase experiments. [ABSTRACT FROM AUTHOR]

Mechanistic aspects of an unusual gas-phase reaction of [LaCH2]+ with halobenzenes have been investigated using Fourier-transform ion cyclotron resonance (FTICR) mass spectrometry combined with density functional theory (DFT) calculations. In this thermal process a carbon-atom from the benzene ring, most likely the ipso-position, and the carbene ligand are coupled to form C2H2. [ABSTRACT FROM AUTHOR]

Gas‐Phase Reactions The thermal reaction of [Ho(CH2S)]+ with toluene giving rise to [C6H5CHSHo]+ and CH4 was investigated using Fourier‐transform ion cyclotron resonance (FT‐ICR) mass spectrometry complemented by DFT calculations. The relatively low capability of “bare” Ho+ to activate C−H bonds has been attributed to the relatively high promotion energy necessary for Ho+ to attain a 4f105d16s1 configuration as well as the low BDEs(Ho+−H). In their Communication on page 4336 ff., H. Schwarz and co‐workers provide an alternative strategy in which Ho+ does function in the activation of toluene. [ABSTRACT FROM AUTHOR]

Gas‐Phase Reactions The thermal reaction of [Ho(CH2S)]+ with toluene giving rise to [C6H5CHSHo]+ and CH4 was investigated using Fourier‐transform ion cyclotron resonance (FT‐ICR) mass spectrometry complemented by DFT calculations. The relatively low capability of “bare” Ho+ to activate C−H bonds has been attributed to the relatively high promotion energy necessary for Ho+ to attain a 4f105d16s1 configuration as well as the low BDEs(Ho+−H). In their Communication on page 4336 ff., H. Schwarz and co‐workers provide an alternative strategy in which Ho+ does function in the activation of toluene. [ABSTRACT FROM AUTHOR]