An Electron Impact Investigation of Some Alkyl Phosphate Esters

Bafus, Donald A.; Gallegos, Emilio J.; Kiser, Robert W.

doi:10.1021/j100880a029

Cited by 74 publications

(37 citation statements)

References 3 publications

(3 reference statements)

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“…These are ions for which the energetics of dissociation are well characterized, and such ions have been employed in mass spectrometry for over 50 years to better understand energy deposition in various processes and instruments [38-49]. For these ions, fragments have defined appearance energies [38-40], the thermodynamics of bond cleavages are known [41, 42], or dissociation kinetics have been measured by a thermal technique, such as blackbody infrared radiative dissociation (BIRD) [43-46]. In all instances, information about the internal energy or effective temperature of the ion as it traverses the mass spectrometer can be obtained from the observed fragmentation.…”

Section: Introductionmentioning

confidence: 99%

How Hot are Your Ions in TWAVE Ion Mobility Spectrometry?

Merenbloom

Flick

Williams

2011

J. Am. Soc. Mass Spectrom.

134

167

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Effective temperatures of ions during traveling wave ion mobility spectrometry (TWIMS) analysis were measured using singly protonated leucine enkephalin dimer as a chemical thermometer by monitoring dissociation of the dimer into monomer, as well as the subsequent dissociation of monomer into a-, b-, and y-ions, as a function of instrumental parameters. At fixed helium cell and TWIMS cell gas flow rates, the extent of dissociation does not vary significantly with either the wave velocity or wave height, except at low (<500 m/s) wave velocities that are not commonly used. Increasing the flow rate of nitrogen gas into the TWIMS cell and decreasing the flow rate of helium gas into the helium cell resulted in greater dissociation. However, the mobility distributions of the fragment ions formed by dissociation of the dimer upon injection into the TWIMS cell are nearly indistinguishable from those of fragment ions formed in the collision cell prior to TWIMS analysis for all TWIMS experiments. These results indicate that heating and dissociation occur when ions are injected into the TWIMS cell, and that the effective temperature subsequently decreases to a point at which no further dissociation is observed during the TWIMS analysis. An upper limit to the effective ion temperature of 449 K during TWIMS analysis is obtained at a helium flow rate of 180 mL/min, TWIMS flow rate of 80 mL/min and traveling wave height of 40 V, which is well below previously reported values. Effects of ion heating in TWIMS on gas-phase protein conformation are presented.

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Section: Introductionmentioning

confidence: 99%

How Hot are Your Ions in TWAVE Ion Mobility Spectrometry?

Merenbloom

Flick

Williams

2011

J. Am. Soc. Mass Spectrom.

134

167

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“…Cleavage of the heterocyclic ring is usually accompanied by the migration of one or more H atoms to the charged or neutral fragments. Fragmentations involving single, double or triple (extensive) H transfers on electron ionization are known to occur in various alkyl esters of phosphinic,11–13 phosphonic12, 14, 15 and phosphoric acids,16–18 and in cyclic phosphates19 and dioxaphosphorinanes 20. The extent of fragmentation to ions with small m/z values varies significantly with the ring size, cleavage being most abundant in compounds with larger cycloalkane rings,21 as demonstrated in most cases by the RA s of the low m/z ions for 3 and 4 as compared with those for 1 and 2 in Table 4.…”

Section: Resultsmentioning

confidence: 99%

Selective Gas Adsorption and Unique Structural Topology of a Highly Stable Guest‐Free Zeolite‐Type MOF Material with N‐rich Chiral Open Channels

Lǐ

et al. 2008

Chemistry A European J

365

131

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A new multifunctional di-topic tetrazolate-based ligand, 2,3-di-1H-tetrazol-5-ylpyrazine (H(2)dtp) has been designed and synthesized. The solvothermal reaction of this ligand with ZnCl(2) gave a robust guest-free three-dimensional zeolite-like chiral metal-organic framework (MOF) complex, [Zn(dtp)], which crystallized in chiral space group P6(1) and possessed chiral open channels with nitrogen-rich walls and the diameter of approximately 4.1 A. This framework presents a unique uniform etd (8,3) topology, is the first example of its type in MOFs, and exhibits high thermal stability with the decomposition temperature above 380 degrees C and permanent porosity. It is interesting that this material is able to selectively adsorb O(2) and CO(2) over N(2) gas, being a rare example in MOFs. In addition, C(2)H(2) and MeOH adsorption results show that although the framework channel holds nitrogen-rich walls that may provide H-bonding sites, no NH H-bond effect between the guest molecules and microporous surface was observed.

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“…Mass 15 amu is found in all data sets. Bafus reports extremely high yields for lighter cations [45]. Because we believe this is an artifact of mass-dependent detector efficiency and analog read-out [46] we exclude his data in our comparison in Figure 7.…”

Section: Trimethyl Phosphatementioning

confidence: 99%

“…Mass 109 amu is formed when the σ P OCH orbital is ionized and the methoxy radical (OCH 3 ) dissociated without previous isomerization [43]. Further dissociation pathways are illustrated by Bafus [45] and Holtzclaw [47] The cation yields as a function of proton energy in Figure 8 is almost constant over the displayed range between 1.55 MeV and 16 MeV. It shows an slight increase of the large fragments around 110 amu and decrease of smaller fragments around 79 amu at higher energies.…”

Section: Trimethyl Phosphatementioning

confidence: 99%

Ion induced fragmentation cross-sections of DNA constituents

et al. 2015

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Abstract. Proton collision with chemical analogs for the base, the sugar and the phosphor residue of the DNA, namely pyrimidine, tetrahydrofuran and trimethyl phosphate, respectively, has been investigated. The impact energies ranged from 300 keV up to 16 MeV. For the first time, relative fragmentation crosssections for proton impact are reported for tetrahydrofuran and trimethyl phosphate; previously reported cross sections for pyrimidine are extended for energies beyond 2500 keV. Ionization of tetrahydrofuran leads to a ring break in about 80% of all events, trimethyl phosphate predominantly fragments by bond cleavage to one of the three methyl-groups and for pyrimidine the parent ion has the highest abundance. Such comparison supports earlier findings that the sugar is the weak spot for strand breaks.

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An Electron Impact Investigation of Some Alkyl Phosphate Esters

Cited by 74 publications

References 3 publications

How Hot are Your Ions in TWAVE Ion Mobility Spectrometry?

How Hot are Your Ions in TWAVE Ion Mobility Spectrometry?

Selective Gas Adsorption and Unique Structural Topology of a Highly Stable Guest‐Free Zeolite‐Type MOF Material with N‐rich Chiral Open Channels

Ion induced fragmentation cross-sections of DNA constituents

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