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This document provides detailed information about the synthesis and characterization of various chemical compounds, including N-Benzyl-2′-(1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1′-biphenyl]-2-carboxamide, N-(4-Methoxybenzyl)-2′-(1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1′-biphenyl]-2-carboxamide, N-(4-Methylbenzyl)-2′-(1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1′-biphenyl]-2-carboxamide, N-(4-Fluorobenzyl)-2'-(1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1'-biphenyl]-2-carboxamide, N-(3-Chlorobenzyl)-2'-(1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1'-biphenyl]-2-carboxamide, N-(4-Phenylbenzyl)-2'-(1H-phenanthro[9,10-d]imidazol-2-yl)-[1,1'-biphenyl]-2-carboxamide [Extracted from the article]

In the last decades, the growing in-orbit population of resident space objects has become one of the main concerns for space agencies and institutions worldwide. In this context, fragmentations further contribute to increase the number of space debris and, operationally, it is fundamental to identify the event epoch as soon as possible, even when just a single fragment orbital state, resulting from an Initial Orbit Determination (IOD) process, is available. This work illustrates the Fragmentation Epoch Detector (FRED) algorithm, which deals with the problem through a stochastic approach, starting from a single fragment IOD result (expressed through mean state and covariance) and parent ephemeris (assumed as deterministic). The process populates the fragment ephemeris with a multivariate normal distribution and, for each couple sample-parent, the epochs of parent transit through the Minimum Orbital Intersection Distance (MOID) are first computed on a time window and then clustered in time. For each cluster, both the three-dimensional MOID and the three-dimensional relative distance distributions are derived, and their similarity is statistically assessed. Given that, at the actual fragmentation epoch, MOID and relative distance were equal, the cluster featuring the best matching between the two distributions is considered as the optimal candidate, and the related fragmentation epoch is returned from the time of parent transit through the MOID, in terms of mean and standard deviation. FRED algorithm performance is assessed through a numerical analysis. The algorithm robustness decreases when parent and fragment orbits share a similar geometry, and results get deteriorated if the perturbations and, moreover, the IOD errors are included in the process, but the correct fragmentation epoch is always present among candidates. Overall, FRED algorithm turns out to be a valid choice in operational scenarios, and a sensitivity analysis tests the algorithm out of the nominal conditions. [ABSTRACT FROM AUTHOR]

The increasing population of resident space objects is currently fostering many space surveillance initiatives, which rely on the use of on-ground sensors. In particular, survey radars allow to first characterise the target orbit from a single transit, through measurements which are Doppler shift, slant range and angular profile. In this framework, the Music Approach for Track Estimate and Refinement (MATER) algorithm was developed to compute the angular track through the MUltiple SIgnal Classification (MUSIC), by solving possible ambiguities which may arise because of the receiver array geometry. This work presents the MATER extension to the case in which multiple sources are simultaneously detected by the sensor. For each detected source, the signal Direction of Arrival (DOA) is computed through MUSIC, and, if no prediction is exploited, possible ambiguous solutions arise. The computation is repeated for the entire observation, and all the estimations related to a specific target are grouped based on the angular sequence shape and the detection epochs. Finally, the possible ambiguity problem is solved, and the angular profile is obtained through a quadratic regression in time. The algorithm is numerically tested on a survey observation simulation. The detection length depends on the impinging signal intensity, and the angular accuracy is in the order of 1e-03 deg. A sensitivity analysis highlights that a transmitted power decrease shortens the detection length, with no remarkable angular accuracy deterioration. An additional simulation shows that in proximity operation monitoring MATER performance depends on the mutual geometry between target and chaser, as it may bring down the reciprocal angular distance under the resolution level. Nevertheless, it is always possible to identify the presence of both sources through the eigenvalues analysis of the signal correlation matrix. Finally, the simulation of a fragments cloud observation highlights that MATER performance depends both on the size of the observed fragment, as this is strictly linked to the signal detected by the receiver, and on the simultaneous detection of other fragments with a more effective signal. • Adaptive beamforming approach for multiple sources scenarios during survey radar observations. • Signal direction of arrival identified through the Multiple Signal Classification (MUSIC) algorithm. • Angular track reconstruction of space objects simultaneously detected. • Applicability to both catalogued and uncatalogued space objects (both operational satellites and space debris). • Support to Space Surveillance and Tracking applications, particularly to fragmentations and proximity operations monitoring. [ABSTRACT FROM AUTHOR]

In this study, a series of azobenzothiazole dyes 4 were synthesized via diazotization of substituted benzothiazole derivatives followed by azo coupling with acetaminophen. The chemical structures of all synthesized compounds were confirmed using analytical data and spectroscopic techniques, including UV-visible, IR, mass spectra, and 1H- and 13C-NMR. The in situ formed diazobenzothiazole ions regiospecifically react with acetaminophen derivatives in the Hollemann-guided electrophilic aromatic substitution mechanism. The regio-orientations were established, on the one hand, by a rigorous interpretation of 1H-NMR spectra and, on the other hand, by the characteristic fragmentation patterns observed on the electrospray mass spectra. In the cases of 4a and 4b, multisubstitutions occurred. The antimicrobial activity of compound 4, along with all the starting materials, was investigated on Pseudomonas aeruginosa PA01, Staphylococcus aureus 18, Escherichia coli 64R, and S. aureus ATCC 25923. The results showed that this skeletal framework exhibited marked potency as antibacterial agents. The most active antibacterial agent against both targeted organisms was compound 4a′.

The discovery of quantum many-body scars (QMBS) both in Rydberg atom simulators and in the Affleckâ€"Kennedyâ€"Liebâ€"Tasaki spin-1 chain model, have shown that a weak violation of ergodicity can still lead to rich experimental and theoretical physics. In this review, we provide a pedagogical introduction to and an overview of the exact results on weak ergodicity breaking via QMBS in isolated quantum systems with the help of simple examples such as the fermionic Hubbard model. We also discuss various mechanisms and unifying formalisms that have been proposed to encompass the plethora of systems exhibiting QMBS. We cover examples of equally-spaced towers that lead to exact revivals for particular initial states, as well as isolated examples of QMBS. Finally, we review Hilbert space fragmentation, a related phenomenon where systems exhibit a richer variety of ergodic and non-ergodic behaviors, and discuss its connections to QMBS. [ABSTRACT FROM AUTHOR]

Following the trade collapse in 2009, Globalisation has recovered but the growth rate slowed down compared to the preceding period of Hyper Globalisation. The persistence of this slowdown is remarkable. We argue that increased awareness of firms for the costs of involvement in global supply chains can explain the recent developments in trade flows. We formalise the existence, length and consequences of changes in fragmentation cost along global supply chains. From a theoretical point of view, we allow tasks to be a combination of different occupations while the model endogenises production fragmentation, allowing for multiple production stages in multiple countries, while remaining tractable. From an empirical point of view, the model explains both the period of Hyper Globalisation and the subsequent Slowbalisation in terms of changing fragmentation costs along global supply chains. The model is also consistent with developments regarding labour market polarisation associated with modern globalisation: the labour market position of medium-skilled workers in advanced countries has deteriorated relative to high- and low-skilled workers, which can be understood by changing global supply chains. Our model implies, however, that even with zero fragmentation costs the demand for certain occupations does not fall to zero for any country. [ABSTRACT FROM AUTHOR]

Cyclobutanols undergo ring expansion with molecular oxygen in the presence of Co(acac)2 to afford 1,2-dioxane-hemiperoxyketals. In the course of acylation, we observed that endoperoxides rearranged into γ-lactone in the presence of triethylamine. Thus, a generalization of this ring contraction through a Kornblum–DeLaMare rearrangement is here reported. Application of this transformation to monosubstituted 1,2-dioxane derivatives also led to 1,4-ketoaldehydes, in proportions depending on the nature of the substituent. These same conditions applied to five-membered dioxolane analogues led to fragmentation instead, through a retro-aldol type process. This study emphasizes the difference of stability of 1,2-dioxane and 1,2-dioxolane against organic bases, 1,2-dioxolanes having proved to be particularly reactive whereas 1,2-dioxanes showed a relative tolerance under these conditions. [ABSTRACT FROM AUTHOR]

Under monotonic tensile and cyclic tensile loading, the occurrence of stochastic brittle fragmentations will affect monotonic and cyclic loading/unloading mechanical behavior of fiber-reinforced ceramic-matrix composites (CMCs). In this work, synergistic effects of stochastic brittle matrix and fiber fragmentations on monotonic and cyclic loading/unloading hysteresis behavior of fiber-reinforced CMCs were investigated. Different matrix fragmentation lengths and distributions of stresses between intact and broken fibers were determined using stochastic fragmentation models, taking into account cyclic loading/unloading hysteresis constitutive relationships. Experimental monotonic tensile and hysteresis curves, matrix fragmentation density, and fiber fragmentation probability for two different SiC/SiC minicomposites were forecasted. Theoretical tensile curves and loading/unloading hysteresis loops for different peak stresses agreed well with the actual data collected. Interface slip is constrained by the debonding of the interface for long matrix brittle fragmentation (LMBF) length and the fragmentation length of the matrix for short matrix brittle fragmentation (SMBF) length. The impacts of fiber volume fraction and fiber's strength on monotonic and cyclic tensile loading/unloading hysteresis loops were analyzed. Fiber volume fraction increase resulted in increased proportional limit stress and tensile fractured strength and decreased tensile failure strain; in addition, the peak strain of hysteresis loops as well as valley strain and area decreased, with increased hysteresis loops modulus for different matrix fragmentations. [ABSTRACT FROM AUTHOR]

Fra gli ultimi decenni dell’800 e i primi del ‘900 un vasto gruppo di intellettuali attivi in differenti campi (letteratura, filosofia, sociologia, critica letteraria, critica artistica, ecc.) imposta il proprio discorso sulla base di rigide coppie binomiali (la più famosa e duratura è quella concernente i concetti di Kultur e Zivilisation) tese a differenziare su principi giustappostivi e a-dialettici due campi d’indagine sempre in radicale contrasto. Benché lo schema interpretativo si adatti a settori quanto mai eterogenei (siano queste le conformazioni consociative ‘comunità’ e ‘società’ in Ferdinand Tönnies, le espressioni artistiche di Rinascimento e Barocco di Heinrich Wölfflin, i concetti di ‘anima’ e ‘forma’ del giovane Lukács o quelli di Riforma e Controriforma del Malaparte fascista, ecc.) le caratteristiche assegnate ai rispettivi termini del binomio si ripetono pressoché identiche da un’analisi all’altra. Dove uno dei termini risulta legato alla catena metonimica dell’Essere e ai concetti di universalità, saldezza, rigidità, unità, ecc., il secondo riferisce alla sfera del particolare, dell’apparenza, della disgregazione, della fluidità, ecc. L’articolo analizza, seguendo alcuni esempi, tanto l’espressione di questa cultura quanto le ragioni del suo formarsi in opposizione allo sviluppo e poi all’egemonia della cosiddetta ‘filosofia della crisi’. Between the last decades of the XIXth century and the first years of the XXth century, several European intellectuals active in different fields (literature, philosophy, sociology, literary critic, art history, etc.) develop a discourse based on rigid dichotomies (the most famous of which is the one regarding the concepts Kulturand Zivilisation) aimed at differentiating, on non dialectical principles, two cultural fields always in radical contrast. Although the same scheme is applied to very different intellectual grounds (the social conformations of ‘community’ and ‘society’ in Ferdinand Tönnies, the artistic expressions of Renaissance and Baroque in Heinrich Wölfflin, the concepts of ‘soul’ and ‘form’ in the young Lukács, or those of Reformation and Counterreformation in the fascist intellectual Curzio Malaparte, etc.) the features attributed to the respective elements of the dichotomiesrepeated across the different analyses. If one the two elements is related to the idea of Being and to the concepts of universality, firmness, rigidity, unity, etc., the second one refers to the particularity, the appearance, the disaggregation, the fluidity, etc.My article analyzes, following several examples, both the manifestation of this culture and the reasons behind its formation.

Organic compounds with geminal diazide units at sp3‐hybridized carbon atoms are a widely neglected class of compounds, with regard to their synthesis and their reactivities. In the last decade, we and others started to uncover reactivity patterns with this compound class, leading to new possibilities of reaction design. This minireview covers recent developments in the field, including the generation of heterocycles through thermolysis, the reactions with nucleophilic amines, and the hydrogenation. [ABSTRACT FROM AUTHOR]

I am worried about the long-lasting effects of the dominant, neo-liberal and capitalist systems that are having a devastating influence on planet Earth and on the life and relations of all the beings, human and non-human, living in this world. When Gregory Bateson wrote "Steps to an Ecology of Mind" (1974) and "Mind and Nature" (1979), he already made clear that human beings do not see the interconnectedness of everything, and because we do not see it, we break it. The breaking of connections has created fractures, wounds and fragmentations in nature, between people, between humans and non-humans: animals, plants and other matter. This has created a gigantic ecological crisis and a profoundly unethical and unjust world with an ever-growing gap between the rich and the poor, the people with resources and those without. We perform our systemic practice in this context. What is our responsibility? In what way can we resist the destructive powers and support actions of hope: lines of flight (Guattari 2015)? We can find inspiration in other areas where activists formulate manifestos as a start of other hopeful practices. In this paper, I give the example of a group of journalists that started The Correspondent and I invite all readers to think about actions that we could start, maybe with a manifesto for systemic practices? Abstract (Dutch) Ik maak me zorgen over de langdurige effecten van het dominante, neo-liberale en kapitalistische systeem die een vernietigende invloed hebben op de planeet aarde en op het leven en de relaties van alle wezens, menselijk en niet menselijk, die in deze wereld leven. Toen Gregory Bateson "Steps to an Ecology of Mind" (1974) en "Mind and Nature" (1979) schreef, maakte hij al duidelijk dat wij mensen niet zien hoe alles met alles verbonden is en omdat we het niet zien verbreken we de verbindingen. Dat verbreken heeft fracturen, wonden en fragmentatie veroorzaakt in de natuur, tussen personen, tussen mensen en niet mensen: dieren, planten en andere materie. Dit heeft een enorme ecologische crisis veroorzaakt en een wezenlijk onethische en onrechtvaardige wereld met een groeiende kloof tussen de rijken en de armen en mensen met of juist zonder toegang tot middelen. Wij voeren onze systemische praktijken uit in deze context. Wat is onze verantwoordelijkheid? Op welke manier kunnen we ons verzetten tegen de destructieve krachten en acties van hoop: lines of flight (Guattari 2015) ondersteunen? We kunnen inspiratie vinden in andere gebieden waar activisten manifesten formuleren als een begin van andere, hoopvolle praktijken. In dit artikel geef ik het voorbeeld van een groep journalisten die de Correspondent startten en ik nodig alle lezers uit om na te denken over acties die wij kunnen starten, misschien met een manifest voor systemische praktijken?

The many applications of photon upconversion—conversion of low‐energy photons into high‐energy photons—raises the question of the possibility of "electron upconversion". In this Review, we illustrate how the reduction potential can be increased by using the free energy of exergonic chemical reactions. Electron (reductant) upconversion can produce up to 20–25 kcal mol−1 of additional redox potential, thus creating powerful reductants under mild conditions. We will present the two common types of electron‐upconverting systems—dissociative (based on unimolecular fragmentations) and associative (based on the bimolecular formation of three‐electron bonds). The possible utility of reductant upconversion encompasses redox chain reactions in electrocatalytic processes, photoredox cascades, design of peroxide‐based medicines, firefly luminescence, and reductive repair of DNA photodamage. Electrons and photons are essential chemical "currencies" that are commonly traded in chemical transformations. The many applications of photon upconversion raises the question of the possibility of "electron upconversion". This Review describes the two common types of electron‐upconverting systems: dissociative (based on unimolecular fragmentations) and associative (based on the bimolecular formation of three‐electron bonds). [ABSTRACT FROM AUTHOR]

Copyright of Enthymema is the property of Enthymema, International Journal of Literary Criticism, Literary Theory & Philosophy of Literature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper spatio-temporally analyses the nexus of landholdings and farm fragmentation (FF) in Peshawar City District, Pakistan. In order to achieve objectives of the study, data were collected from revenue department and field survey. For micro level analysis, five villages were randomly selected for detailed and intensive study. In addition to questionnaire survey, detailed focused group discussion was also arranged with the key stakeholders. The analysis reveals that rapid urban expansion has resulted in reduction of farmland and sub-division of landholdings into smaller land fragments. Beside urbanization, a major contributor to fragmentation is the law of inheritance, which divides the land among successors. In the absence of specific policies on land consolidation or development control, it is hard to see any expected change in landholding and farm fragmentation and continued invasion of farmland by urban uses. [ABSTRACT FROM AUTHOR]

The present distribution of intact objects is a good proxy to quantify the catastrophic collision risk and consequences in the coming decades. The results of a large number of long term simulations of the LEO environment perturbed by the collisional fragmentation of massive objects are used to identify the main driving parameters of the long term collisional evolution of the debris population and measure the danger represented by “typical” classes of space objects. An evaluation norm, able to highlight the differences between comparative long term evolution scenarios and to give a quantitative measure of the effects of specific parameters affecting the evolution, is devised. It is shown how, for collisional fragmentations in LEO, due to the highly stochastic evolution of the LEO environment, even the fragmentation of a massive spacecraft might not be able to alter the long term evolution of the LEO population beyond the intrinsic statistical variability associated with the Monte Carlo procedure. Among the parameters determining the long term effects of a collisional fragmentation in LEO, a combination of mass and altitude of the event appears to be the driving factor. In GEO, the situation is different, and the addition of a massive fragmentation lives a signature on the environment that is detectable throughout the investigated time span, with the mass being the only factor important to asses the long term consequences of a collisional fragmentation. [ABSTRACT FROM AUTHOR]

The future space debris environment will be governed by the production of fragments coming from massive breakups. In order to identify the most relevant parameters influencing the long term evolution of the environment and to assess the criticality of selected space objects in different regions of the circumterrestrial space, a large parametric study was performed. In this framework some indicators were produced to quantify and rank the relevance of selected fragmentations on the long term evolution of the space debris population. Based on the results of the fragmentation studies, a novel analytic index, the Criticality of Spacecraft Index (CSI), aimed at ranking the environmental criticality of abandoned objects in Low Earth Orbit (LEO), was formulated. It takes into account the physical characteristics of a given object, its orbit and the environment where this is located. The results corresponding to a sample of LEO objects in the initial population at the epoch of January 1, 2020 and mass larger than 100 kg are shown. [ABSTRACT FROM AUTHOR]

Copyright of Revista Tamoios is the property of Editora da Universidade do Estado do Rio de Janeiro (EdUERJ) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Field programmable gate arrays (FPGAs) are designed to implement any logic circuit with the ability to host several independent tasks simultaneously. They inherit reconfigurability from their programmable architecture. However, designs are usually dynamic and the arrival times of tasks may be unknown in advance. Accordingly, FPGA should have the ability to: (1) place incoming tasks at run time, and (2) compact the chip whenever needed. Compaction is a proposed solution to alleviate external fragmentations. It tries to move running tasks closer to each others to free a sufficient area for hosting more tasks. Unfortunately, traditional compaction techniques suffer from internal and external fragmentations. This paper introduces a novel puzzle-based compaction (PBC) technique. PBC is a shape-aware technique that is the first to take the task shape into consideration. Hence, it succeeds not only to eliminate the internal fragmentations but also to minimize the external fragmentations. Moreover, the paper develops a novel formula, which is the first not to estimate, but to exactly calculate the amount of external fragmentations generated by hosting a set of tasks inside the reconfigurable chip. Experimental results have shown that PBC outperforms recent compaction techniques in which the chip utilization has reached 87 %. [ABSTRACT FROM AUTHOR]

Abstract: Recent developments (since the last review in J. of Physics G by I. Tanihata in 1996 [1]) at RIB facilities opened possibilities of detailed studies of halo nuclei. New facilities have been constructed to provide higher intensity beams of radioactive nuclei in a wide range of energies. At the time of the last review, only secondary beams by projectile fragmentation were the production source of halo nuclei for use in reaction studies. Since then, re-acceleration facilities have been developed and thus high-quality low-energy beams become available for the reaction studies. The wide variety of new data are thus available on halo nuclei and nuclei on and outside of proton and neutron drip lines. Low energy beams provided a means to determine the masses and charge radii of halo nuclei (6,8He, 11Li). Also transfer reactions have been measured in many nuclei far from the stability line. In fragmentation facilities, new experimental methods such as gamma ray detection in coincidence with breakup fragments of halo nuclei have been developed. Also the reaction cross sections have been measured in a wide range of beam energies. In addition, proton elastic scattering of halo nuclei has been measured at high energies. All together, studies of density distribution, identification of shell orbitals and spectroscopic factors of halo wave function became possible. Such studies reveal many new important information such as the change of magic numbers in nuclei far from the stability line. In this article, we would like to review the experimental developments on halo nuclei and other related drip line nuclei. Also the new view of the nuclear structure learned from such studies will be discussed. Development of selected theories on related nuclear structure problems will be mentioned briefly. [Copyright &y& Elsevier]

Three different cases of interparticle collisions were simulated to observe the fragmentation mechanisms of composite particles. It was found that the cracking mechanism in interparticle collisions is different from that observed in particle-wall collisions. By means of DEM simulations, it was observed that the primary interparticle bonds break in both tension and shear. Depending on the type of interparticle collisions, cracks and fragments are generated. In general, finer fragments are generated around the impact site of the particles and are surrounded by larger fragments. From DEM simulations, it was found for the most part that the impacting particles exhibit more damage than the stationary particles. The symmetrical loading showed almost the same amount of damage to both types of particles. The discontinuous nature of the material and the unsymmetrical loading caused unsymmetrical damages (crack patterns). In unsymmetrical loadings, the impacting particle was more damaged and had more cracks than the stationary particle. [ABSTRACT FROM AUTHOR]

Abstract: The fragmentation behaviour of protonated O,O-dimethyl ethylphosphonate and its isotopomers deuterated in the α- and β-positions of the ethyl group and their fragment ions, particulary EtP(O)OMe+(IV), have been investigated both experimentally in an ion trap mass spectrometer and theoretically by electronic structure calculations at the B3LYP level. Of particular interest is the finding that the phosphonium ion IV eliminates ethene with hydrogen/deuterium loss from both the α-and β-positions. The initial step for both routes involves ethyl migration from P to O to form the ion MeOP+OEt which then loses ethene by two mechanisms, both of which lead to the same products. That a unitary branching ratio for α- and β-elimination is not observed indicates that although the final step of dissociation into product ion and ethene is energetically the most demanding, it is not rate limiting and the large entropy change associated with the dissociation allows earlier processes to determine the branching ratio. This demonstrates once again that free energy, not enthalpy (or energy), determines the course of gas phase ion processes. [Copyright &y& Elsevier]

The reactions of Ar+ with 3-azidopropionitrile, 2-azidopropionitrile, and azidoacetonitrile have been studied in a Fourier transform ion cyclotron resonance mass spectrometer. The dominant and, in the case of 2-azidopropionitrile the only, primary reaction is charge transfer although the resultant molecular ion immediately fragments. In the cases of 3-azidopropionitrile and azidoacetonitrile a small amount of hydrogen abstraction to form ArH+ occurs. In addition to the unambiguous identification of the molecular formula of the product ions leading in most cases to suggested chemical structures with known proton affinities, the time profiles of the product ions were determined and kinetic analysis allowed the primary product ions to be differentiated from the secondary product ions. Many secondary reactions of the primary ions with the parent neutral molecule occur, the majority initiated by proton transfer. Some of them lead to fragmentation but others to the protonated azidonitrile. A comparison with a recently published account of the EI fragmentation of the same three azidonitriles leads to the suggestion that Ar+ chemical ionisation is potentially more appropriate for investigating the decomposition of fragile molecules such as the azidonitriles than is EI. [Copyright &y& Elsevier]

A graphite target is bombarded at very low pressures with molecular beams of dihydrogen and dinitrogen, in the presence of low-pressure dioxygen. The large variety of complex organic molecules thus produced have been characterized by their mass spectra (molecular and fragmentation peaks) and identified by comparison of these spectra with authentic samples. This extends the variety of complex biological substances obtained in these ‘interstellar-like’ conditions. [Copyright &y& Elsevier]

Sodiated lysoglycerophosphatidylethanolamine (LGPE) and lysoglycerophosphatidylcholine (LGPC) species dissociate under low collision energy by covalent bond cleavage resulting in product ions with either sodium retention or without sodium retention. For explaining these fragmentations, sodium chelation by heteroatoms (as charge-solvated structures) is often considered, and consequently, under keV collision conditions, sodium is "spectator" of cleavages (charge remote fragmentation). However, cleavage of such charge-solvated forms under low-energy conditions should result in sodium desolvation rather than covalent bond cleavage. In the present study, protonated salts are proposed as the main representative structures of the sodiated LGPE and LGPC forms. These structures are generated from sodiation of zwitterionic and betaine forms of LGPE and LGPC molecules, respectively. Experimental evidence to determine which structure is involved in the dissociations is provided, especially by comparing the dissociation of LGPL sodiated forms with that of sodiated polyethylene glycols. Energy-resolved mass spectrometry breakdown experiments were performed on a quadrupole time-of-flight instrument to demonstrate that both LGPE and LGPC sodiated forms exist as protonated salt structures. From such structures, proton migration by prototropy can result in different bond cleavages whereas the salt moiety remains spectator of these processes.