Electrospray ionization enters the final frontier: Mass spectrometry's role in understanding electrospray thrusters and their plumes

Patrick, Amanda L.

doi:10.1002/rcm.8587

Cited by 13 publications

(19 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…25 Mass spectrometry and ion mobility spectrometry (IMS) have been powerful tools for elucidating the structure and examining the reactivity and reaction dynamics of IL clusters. 26 Energy-resolved collision-induced dissociation (CID) experiments have been performed to elucidate the gas-phase energetics and dissociation mechanisms of aprotic and protic ILs for applications in space propulsion 27−29 and to elucidate relative affinities of various cations and anions that comprise common ILs. 30−33 IMS experiments have investigated the formation of IL clusters, IL cluster distributions and magic number clusters, and ion evaporation processes that occur during the ESI process.…”

Section: ■ Introductionmentioning

confidence: 99%

“…Infrared (IR) spectroscopy of solvated clusters of the [C 4 mim] + cation has also been performed to elucidate the effects of solvation of IL cations in water . Mass spectrometry and ion mobility spectrometry (IMS) have been powerful tools for elucidating the structure and examining the reactivity and reaction dynamics of IL clusters . Energy-resolved collision-induced dissociation (CID) experiments have been performed to elucidate the gas-phase energetics and dissociation mechanisms of aprotic and protic ILs for applications in space propulsion − and to elucidate relative affinities of various cations and anions that comprise common ILs. − IMS experiments have investigated the formation of IL clusters, IL cluster distributions and magic number clusters, and ion evaporation processes that occur during the ESI process. − For example, IL clusters of the [5C:4A] + stoichiometry exhibit high stability, that is, magic number clusters, for at least two ILs. , Further, in addition to single ion-pair losses (C:A) upon dissociation, simultaneous loss of clusters involving multiple ion pairs, (C:A) n , has been reported for select IL clusters. , …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Gas-Phase Binding Energies and Dissociation Dynamics of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters

2020

View full text Add to dashboard Cite

Ionic liquids (ILs) have become increasingly popular due to their useful and unique properties, yet there are still many unanswered questions regarding their fundamental interactions. In particular, details regarding the nature and strength of the intrinsic cation–anion interactions and how they influence the macroscopic properties of ILs are still largely unknown. Elucidating the molecular-level details of these interactions is essential to the development of better models for describing ILs and enabling the purposeful design of ILs with properties tailored for specific applications. Current uses of ILs are widespread and diverse and include applications for energy storage, electrochemistry, designer/green solvents, separations, and space propulsion. To advance the understanding of the energetics, conformations, and dynamics of gas-phase IL clustering relevant to space propulsion, threshold collision-induced dissociation approaches are used to measure the bond dissociation energies (BDEs) of the 2:1 clusters of 1-alkyl-3-methylimidazolium cations and tetrafluoroborate, [2C n mim:BF4]+. The cation, [C n mim]+, is varied across the series, 1-ethyl-3-methylimidazolium [C2mim]+, 1-butyl-3-methylimidazolium [C4mim]+, 1-hexyl-3-methylimidazolium [C6mim]+, and 1-octyl-3-methylimidazolium [C8mim]+, to examine the structural and energetic effects of the size of the 1-alkyl substituent on binding. Complementary electronic structure calculations are performed to determine the structures and energetics of the [C n mim]+ and [BF4]− ions and their binding preferences in the (C n mim:BF4) ion pairs and [2C n mim:BF4]+ clusters. Several levels of theory, B3LYP, B3LYP-GD3BJ, and M06-2X, using the 6-311+G(d,p) basis set for geometry optimizations and frequency analyses and the 6-311+G(2d,2p) basis set for energetics, are benchmarked to examine their abilities to properly describe the nature of the binding interactions and to reproduce the measured BDEs. The modest structural variation among these [C n mim]+ cations produces only minor structural changes and variation in the measured BDEs of the [2C n mim:BF4]+ clusters. Present findings indicate that the dominant cation–anion interactions involve the 3-methylimidazolium moieties and that these clusters are sufficiently small that differences in packing effects associated with the variable length of the 1-alkyl substituents are not yet significant.

show abstract

Section: ■ Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gas-Phase Binding Energies and Dissociation Dynamics of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters

2020

View full text Add to dashboard Cite

show abstract

“…5,[24][25][26][27][28] A discussion of the role of mass spectrometry (MS) in understanding electrospray thrusters and their plumes has recently been published. 29 Additionally, vacuum electrospray of ionic liquids has also been investigated for applications, such as secondary ion MS. [30][31][32] Although not specifically ESI, it is worth noting that there have also been mass spectrometric studies on the nature of evaporated ionic liquids in the gas phase. [33][34][35][36] Gas-phase dissociation studies have concerned both clusters and bare cations.…”

Section: Previous Mass Spectrometric Studies Of Ionic Liquidsmentioning

confidence: 99%

Thermal‐ and collision‐induced dissociation studies of functionalized imidazolium‐based ionic liquid cations

2020

Self Cite

View full text Add to dashboard Cite

Ionic liquids are now used in applications ranging from chemical synthesis to spacecraft propulsion. With this comes the need to characterize new syntheses, identify environmental contamination, and determine eventual fate in terrestrial and space environments. This work investigates the effects of source conditions, particularly capillary temperature, on the observed mass spectrum and determines the collision‐induced dissociation (CID) patterns of imidazolium‐based ionic liquid cations as a function of their substituent types. Experiments were carried out on a Thermo LTQ‐XL ion‐trap mass spectrometer and a Bruker microTOF‐Q II mass spectrometer. Dissociation of the imidazolium cations occurred predominantly via substituent losses, except in benzyl‐substituted systems, for which the neutral loss of the imidazole was exclusively observed. Several of these dissociation pathways were studied in greater depth using complementary quantum chemical calculations. The nature of the neutral losses from the substituents was found to be highly dependent upon the nature of the substituent, as would be expected, establishing bases for characterization.

show abstract

“…Knowledge of the gas-phase reaction dynamics and intrinsic binding interactions of ILs can aid in the elucidation of that knowledge and help lead the development of task-specific ILs. Electrospray propulsion has the benefits of easy miniaturization and low complexity making this propulsion technique amenable to nanosatellite propulsion . The propulsion mechanism associated with electrospray thrusters parallels that of electrospray ionization (ESI), presently one of the most commonly employed ionization techniques for mass spectrometry (MS).…”

Section: Introductionmentioning

confidence: 99%

“…The ions are accelerated in the electric field, generating thrust as the ions are emitted from the spacecraft. The thrust generated is generally very small, therefore an array of emitters are needed to generate the required thrust of a small nanosatellite …”

Section: Introductionmentioning

confidence: 99%

Absolute Trends and Accurate and Precise Gas-Phase Binding Energies of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters from Combined Independent and Competitive TCID Measurements

Roy

Rodgers

2020

J. Phys. Chem. A

View full text Add to dashboard Cite

Ionic liquid (IL) development efforts have focused on achieving desired properties via tuning of the IL through variation of the cations and anions. However, works geared toward a microscopic understanding of the nature and strength of the intrinsic cation−anion interactions of ILs have been rather limited such that the intrinsic strength of the cation−anion interactions in ILs is largely unknown. In previous work, we employed threshold collision-induced dissociation approaches supported and enhanced by electronic structure calculations to characterize the nature of the cation− anion interactions in and determine the bond dissociation energies (BDEs) of a series of four 2:1 clusters of 1-alkyl-3-methylimidazolium cations and tetrafluoroborate anions, [2C n mim:BF 4 ] + . The cation was varied over the series: 1-ethyl-3-methylimidazolium, [C 2 mim] + , 1-butyl-3-methylimidazolium, [C 4 mim] + , 1-hexyl-3-methylimidazolium, [C 6 mim] + , and 1-octyl-3-methylimidazolium, [C 8 mim] + , to determine the structural and energetic effects of the size of the 1-alkyl substituent on the binding. The variation in the strength of binding determined for these [2C n mim:BF 4 ] + clusters was found to be similar in magnitude to the average experimental uncertainty in these determinations. To definitively establish an absolute order of binding among these [2C n mim:BF 4 ] + clusters, we extend this work here to include competitive binding studies of three mixed 2:1 clusters of 1-alkyl-3-methylimidazolium cations and tetrafluoroborate anions, [C n−2 mim:BF 4 :C n mim] + for n = 4, 6, and 8. Importantly, the results of the present work simultaneously provide the absolute BDEs of these mixed [C n−2 mim:BF 4 :C n mim] + clusters and the absolute relative order of the intrinsic binding interactions as a function of the cation with significantly improved precision. Further, by combining the thermochemical results of the previous and present studies, the BDEs of the [2C n mim:BF 4 ] + clusters are more accurately and precisely determined.

show abstract

Electrospray ionization enters the final frontier: Mass spectrometry's role in understanding electrospray thrusters and their plumes

Cited by 13 publications

References 45 publications

Gas-Phase Binding Energies and Dissociation Dynamics of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters

Gas-Phase Binding Energies and Dissociation Dynamics of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters

Thermal‐ and collision‐induced dissociation studies of functionalized imidazolium‐based ionic liquid cations

Absolute Trends and Accurate and Precise Gas-Phase Binding Energies of 1-Alkyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquid Clusters from Combined Independent and Competitive TCID Measurements

Contact Info

Product

Resources

About