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This article aims to present the evolution and further perspectives of the external action by the European Union Agency for Law Enforcement Training (CEPOL). By analysing the legal background in light of the subsequent mandates of the Agency and against various policy documents, the authors demonstrate the impressive evolution of the past 20 years, both in terms of volume and quality, that has made CEPOL a key player in the European Union’s internal-external security nexus. The Agency has managed to engage nearly all countries in the EU’s proximity on the one hand by concluding cooperation instruments, on the other hand by managing dedicated capacity-building projects. Via all these means, the European law enforcement culture is spread among partner countries’ law enforcement communities. CEPOL is thus actively contributing to the high level of internal security of the European Union, serving its primary customers, i.e. the EU Member States, and well beyond the borders of the Union.

Two allyl-palladium(II) complexes bearing the Trost standard ligand (1), i.e., [(C3H5)Pd(S,S-1)]+CF3SO3−and [(c-C6H9)Pd(S,S-1)]+BArF−(BArF−= [B((3,5-(CF3)2)C6H3)4]−), are investigated using electrospray ionization (ESI) mass spectrometry. Both species form abundant quasi-molecular ions [(C3H5)Pd(S,S-1)]+and [(c-C6H9)Pd(S,S-1)]+, respectively. At elevated concentrations of the solutions admitted to the ESI source, significant aggregation to binuclear species is observed, which agrees with recent results from solution chemistry. Consistent with solution-phase studies, the tendency of clustering is much less pronounced for the bulky BArF−counterion compared to the smaller triflate. [ABSTRACT FROM AUTHOR]

The ion–molecule reactions of C7H7+ions with neutral toluene are investigated in an ion-trap mass spectrometer, which is shown to be suitable instrumentation for kinetic studies, although the absolute rate constant can only be derived with difficulties. The benzylium ions C6H5CH2+undergo a formal CH2+transfer with toluene to afford the corresponding xylenium ions, CH3–C6H4–CH2+, whereas the tropylium ions c-C7H7+do not react. The results for the parent compound C7H7+are complemented with data for the tert-butyl derivative generated by collision-induced dissociation of the corresponding p-(tert-butyl)benzyl pyridinium ion. For the tert-butyl substituted ion, the benzylium/tropylium dichotomy exists in a similar manner in that reactive and non-reactive fractions are observed, of which the former is assigned to the benzylium structure on the basis of infrared-multiphoton dissociation spectra. [ABSTRACT FROM AUTHOR]

The collision-induced fragmentation behavior of cationic [Pt(CX3)(L)]+complexes (X = H, D; L = 1,10-phenanthroline (phen), 2,2′-bipyrimidine (bipyrm), 2,2′-bipyridine (bipy), and (o,o′-Cl2C6H3)NC(CH3)−C(CH3)N(o,o′-Cl2C6H3) (MeDABDCP)) and their thermal reactions with C6H6, [1,2,3]-C6H3D3, [1,3,5]-C6H3D3, and C6D6were probed in gas-phase experiments. Collision-induced dissociations of the phen and bipyrm complexes result in preferential eliminations of neutral PtCH2to afford the protonated heterocyclic ligands LH+as ionic products; the bipy complex favors loss of methane due to a “rollover” cyclometalation process. Fragmentation of the MeDABDCPcomplex leads to the elimination of up to four HCl molecules from the ligand; neither PtCH2nor methane is liberated. In their bimolecular reactions with benzene, all platinum complexes lose methane from the initially formed adducts. The complexes with L = phen, bipyrm, and bipy react much more efficiently with benzene than the MeDABDCPcomplex, and only in the latter case is significant adduct formation observed. For the formation of methane in the ion/molecule reactions of the complexes with deuterated benzenes, a microkinetic model was applied for fitting of the observed isotope patterns, which reveals the following: (i) the C−H bond activation of benzene prior to methane elimination is reversible, (ii) while for the MeDABDCPcomplex the rate of H/D exchange is lower than that for the liberation of methane, an opposite behavior holds true for the other complexes; (iii) the overall kinetic isotope effects associated with the H/D exchange amount to ca. 1.5 for the phen, bipyrm, and bipy complexes. DFT calculations demonstrate that the popular B3LYP method fails to explain the observed H/D exchange but that the functionals mPW1k, M05-2X, and mPW1PW91 can account for the experimental findings. Nevertheless, serious discrepancies seem to exist that prevent an unambiguous distinction of mechanistic scenarios, i.e., oxidative addition/reductive elimination versus σ-CAM process. [ABSTRACT FROM AUTHOR]

Mass spectrometric experiments are used to examine the size-dependent interactions of bare vanadium cluster cations Vn+(n= 1−7) with methanol. The reactivity patterns exhibit enormous size effects throughout the range of clusters investigated. For example, dehydrogenation of methanol to produce VnOC+is only brought about by clusters with n≥ 3. Atomic vanadium cation V+also is reactive, but instead of dehydrogenation of the alcohol, expulsions of either methane or a methyl radical take place. In marked contrast, the reaction efficiency of the dinuclear cluster V2+is extremely low. For the cluster cations Vn+(n= 3−7), complete and efficient dehydrogenation of methanol to produce VnOC+and two hydrogen molecules prevails. DFT calculations shed light on the mechanism of the dehydrogenation of methanol by the smallest reactive cluster cation V3+and propose the occurrence of chemisorption concomitant with C−O bond cleavage rather than adsorption of an intact carbon monoxide molecule by the cluster. [ABSTRACT FROM AUTHOR]

Using doubly ionized acetylene as a superelectrophilic reagent, the new rare-gas compounds HCCAr2+and HCCKr2+have been prepared for the first time in hyperthermal collisions of mass-selected C2H22+with neutral rare gases (Rg). However, electron transfer from the rare gas to the acetylene dication as well as proton transfer from C2H22+to the rare gas efficiently compete with formation of HCCRg2+. The computational investigations show that the formation of HCCRg2+from acetylene dication is endothermic with Rg = He, Ne, Ar and Kr and only weakly exothermic with Xe. These energetic factors, as well as the pronounced competition with the other reactive channels help to explain why HCCRg2+is only observed with Rg = Ar and Kr. [ABSTRACT FROM AUTHOR]

Mechanistic details for the formation of methane from the title compound as well as the combined elimination of CH32SCH4are derived from various massspectrometric experiments including deuteriumlabeling studies and DFT calculations. For the first process, i.e., methane formation, we have identified three competing pathways in which the intact, Ptbonded methyl group combines with a Hatom that originates from a phenyl substituent ca.7, the dimethyl sulfide ligand ca.41, and a methyl group of the diazabutadiene backbone ca.52. In contrast, in the combined CH32SCH4elimination, the methane is specifically formed from the Ptbound CH3group and a Hatom provided by one of the phenyl groups ‘cyclometalation’. [ABSTRACT FROM AUTHOR]

The bimolecular reactivity of the CO22+ dication with neutral CO2 is investigated using triple quadrupole and ion–ion coincidence mass spectrometry. Crucial for product analysis is the use of appropriate isotope labelling in the quadrupole experiments in order to distinguish the different reactive pathways. The main reaction corresponds to single-electron transfer from the neutral reagent to the dication, i.e. CO22+ + CO2 → 2CO2+; this process is exothermic by almost 10 eV, if ground state monocations are formed. Interestingly, the results indicate that the CO2+ ion formed when the dication accepts an electron dissociates far more readily than the CO2+ ion formed from the neutral CO2 molecule. This differentiation of the two CO2+ products is rationalized by showing that the population of the key dissociative states of the CO2+ monocation will be favoured from the CO22+ dication rather than from neutral CO2. In addition, two bond-forming reactions are observed as minor channels, one of which leads to CO+ and O2+ as ionic products and the other affords a long-lived C2O32+ dication. [ABSTRACT FROM AUTHOR]

Electrospray ionization of a methanolic solution of Michler's hydrol blue, bis(4-(N,N-dimethylamino)phenyl)methyl tetrafluoroborate, 1BF4-, produces the formal methanol adduct 1·CH3OH, which shows an unusual gas-phase chemistry. Tandem mass-spectrometry experiments and complementary theoretical studies indicate that this adduct corresponds to the methyl ether of Michler's hydrol protonated at one of the dimethylamino groups, cation 3. Collision-induced dissociation of mass-selected 3leads to two sequential expulsions of open-shell species, resulting in a formal loss of C2H6O, whereas no expulsion of methanol is observed. In contrast, interaction of gaseous 3with a single molecule of a suitable base triggers an exoergic loss of methanol via proton-shuttle catalysis within the collision complex. The occurrence of this exothermic proton transfer also prevents the application of the otherwise successful kinetic method for the determination of the gas-phase proton affinity of the methyl ether of Michler's hydrol. [ABSTRACT FROM AUTHOR]

The bimolecular reactivity of molecular dications in the gas phase is reviewed from an experimental point of view. Recent research has demonstrated that in addition to the ubiquitous occurrence of electron transfer in the reactions of gaseous dications with neutral molecules, bond-forming reactions play a much larger role than anticipated before. Thus, quite a number of hydrogen-containing dications show proton transfer to neutral reagents as an abundant or even as the major pathway, and also the nature of the neutral reagent itself is decisive for the amount of proton transfer which takes place. Further, several hydrocarbon dications CmHn2+ of medium size (m = 6–14, n = 6–10) undergo bond-forming reactions with unsaturated hydrocarbons such as acetylene or benzene, thereby offering new routes for the formation of larger aromatic compounds under extreme conditions such as interstellar environments. Likewise, recent results on the bimolecular reactivity of multiply charged metal ions have revealed the occurrence of a number of new bond-forming reactions which open promising prospects for further research. [ABSTRACT FROM AUTHOR]

A mechanistically unprecedented situation characterizes the gas-phase ion chemistry of Ni(C,H3,O)+ when reacted under thermal, single-collision conditions with ethane. A dehydrogenation channel leading to Ni(C3,H7,O)+ is to 90% preceded by a complete loss of positional identity of all nine H-atoms of the encounter complex (‘scrambling’), whereas ca. 10% of the reaction exhibit a selective C—H bond activation of the alkane. In addition, a degenerate H exchange between ethane and the (C,H3,O) unit occurs as a side reaction, the mechanistic details of which remain unknown for the time being. [ABSTRACT FROM AUTHOR]

The bimolecular reactions of several hydrocarbon dications CmHn2+ (m = 6–10, n = 4–9) with neutral benzene are investigated by tandem mass spectrometry using a multipole instrument. Not surprisingly, the major reaction of CmHn2+ with benzene corresponds to electron transfer from the neutral arene to the dication resulting in the pair of monocationic products CmHn+ + C6H6+. In addition, also dissociative electron transfer takes place, whereas proton transfer from the CmHn2+ dication to neutral benzene is almost negligible. Interestingly, the excess energy liberated upon electron transfer from the neutral arene to the CmHn2+ dication is not equally partitioned in the monocationic products in that the cations arising from the dicationic precursor have a higher internal energy content than the monocations formed from the neutral reaction partner. In addition to the reactions leading to monocationic product ions, bond-forming reactions with maintenance of the two-fold charge are observed, which lead to a condensation of the CmHn2+ dications with neutral benzene under formation of intermediate Cm+6Hn+62+ species and then undergo subsequent losses of molecular hydrogen or neutral acetylene. This reaction complements a recently proposed dicationic route for the formation of polycyclic aromatic hydrocarbons under extreme conditions such as they exist in interstellar environments. [ABSTRACT FROM AUTHOR]

The structures of C7H9ions generated by protonation of toluene are investigated by means of gas-phase infrared spectroscopy in conjunction with labeling experiments and complementary mass spectrometric studies. In full consistency with previous studies, the unimolecular as well as the multiphoton-induced dissociation of mass-selected C7H9ions lead to losses of molecular hydrogen and methane. Labeling data clearly imply the occurrence of skeletal rearrangements of protonated toluene to isomeric structures in the course of fragmentation. Complementary reactivity studies indicate, however, that the C7H7ions generated upon dehydrogenation of C7H9bear the benzylium structure, rather than that of the more stable tropylium ion. Combination of labeling data and extensive theoretical studies lead to a scheme for the fragmentation of protonated toluene, which can account for all experimental findings reasonably well. As far as infrared spectroscopy of gaseous ions is concerned, the present results confirm the structural predictions derived from theory and provide evidence for the existence of protonated cycloheptatriene but also pose some questions about the comparability of intensities in multiphoton dissociation and linear absorption spectra. [ABSTRACT FROM AUTHOR]

Bare vanadium-oxide and -hydroxide cluster cations (VmOnHo+, m = 2−4, n = 1−10, o = 0, 1) were generated by electrospray ionization in order to examine their intrinsic reactivity toward isomeric butenes and small alkanes using mass spectrometric techniques. Two of the major reactions described here concern the activation of C−H bonds of the alkene/alkane substrates resulting in the transfer of two hydrogen atoms and/or attachment of the dehydrogenated hydrocarbon to the cluster cations; these processes are classified as oxidative dehydrogenation (ODH) and dehydrogenation, respectively. For the dehydrogenation of butene, it evolved as a general trend that high-valent clusters prefer ODH resulting in the addition of two hydrogen atoms to the cluster concomitant with elimination of neutral butadiene, whereas low-valent clusters tend to add the diene with parallel loss of molecular hydrogen. Deuterium labeling experiments suggest the operation of a different reaction mechanism for V2O2+ and V4O10+ compared to the other cluster cations investigated, and these two cluster cations also are the only ones of the vanadium-oxide ions examined here that are able to dehydrogenate small alkanes. The kinetic isotope effects observed experimentally imply an electron transfer mechanism for the ion−molecule reactions of the alkanes with V4O10+. [ABSTRACT FROM AUTHOR]

Structural aspects and the unimolecular fragmentations of doubly protonated benzene are studied by means of tandem-mass spectrometry. The corresponding dications are generated by electron ionization (EI) of 1,3- and 1,4-cyclohexadienes, respectively. It is suggested that EI of 1,3-cyclohexadiene leads to the singlet state of doubly protonated benzene, whereas EI of 1,4-cyclohexadiene yields a mixture of singlet and triplet states. Unimolecular fragmentation of doubly protonated benzene exclusively proceeds via dehydrogenation leading to the benzene dication. The proton affinities (PAs) of protonated benzene amount to PA(C6H7+)meta = 1.9 ± 0.3 eV for protonation taking place at the meta-position, PA(C6H7+)ortho = 1.5 ± 0.2 eV, and PA(C6H7+)para = 0.9 ± 0.2 eV, respectively. Various facets of the experiments are compared with density functional theory calculations and generally good agreement is found. [ABSTRACT FROM AUTHOR]

The concept of using disulfides as an oxidant for Cu(i) is introduced as part of a Cu-catalyzed process leading to the formation of benzothiazole from an iminodisulfide under an inert atmosphere. [ABSTRACT FROM AUTHOR]

The bimolecular reaction of mass-selected CH3Br2+/CH2BrH2+ dications with argon leads to the rare-gas carbene cation ArCH2+, which represents an example of a new kind of organo rare-gas compound. [ABSTRACT FROM AUTHOR]