Entropy effects in gas phase ion-molecule association reactions

Innorta, G.; Torroni, Sandro; Maranzana, Andrea; Tonachini, Glauco

doi:10.1016/s0022-328x(00)00945-1

Cited by 14 publications

(11 citation statements)

References 45 publications

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“…A lower energy for states with higher multiplicity has been already reported for the ion C 5 H 5 Fe + [25,10] and is also found for C 5 H 5 Co + [26].…”

Section: Computational Studysupporting

confidence: 74%

“…In a series of papers [6][7][8][9] Bohme et al demonstrated that C 5 H 5 Fe + ions react with faster rates compared to that of the naked Fe + ion and that the reactions with NO or CO lead to the sequential addition of two and three molecules. The efficiency of the reactions of several C 5 H 5 M + ions have been studied [10] and it was indicated that a positive activation entropy could be responsible of the low efficiency found in several cases.…”

Section: Introductionmentioning

confidence: 99%

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Reactions of C5H5M+ (M=Fe, Ni) with substituted thiophenes

Innorta¹,

Torroni²

2006

Journal of Organometallic Chemistry

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“…A lower energy for states with higher multiplicity has been already reported for the ion C 5 H 5 Fe + [25,10] and is also found for C 5 H 5 Co + [26].…”

Section: Computational Studysupporting

confidence: 74%

Section: Introductionmentioning

confidence: 99%

Reactions of C5H5M+ (M=Fe, Ni) with substituted thiophenes

Innorta¹,

Torroni²

2006

Journal of Organometallic Chemistry

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“…Innorta and co-workers (Innorta, Pontoni, & Torroni, 1998;Innorta et al, 2001Innorta et al, , 2002 have used an ion trap to explore the kinetics of ion/molecule reactions between cationic metal/cyclopentadienyl complexes and a variety of coordinating ligands such as alcohols, ethers, and amines. The reactions generally lead to adducts and there is a correlation between the rate constants and the ionization potential of the ligand (a lower ionization potential leads to a higher rate).…”

Section: ð5þmentioning

confidence: 99%

Quadrupole ion trap studies of fundamental organic reactions

Gronert

2004

Mass Spectrometry Reviews

128

133

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Over the past several decades, quadrupole ion traps have become important instruments in the study of gas phase ion/molecule reactions. As a part of this work, they have been employed in a number of studies focused on fundamental organic reaction mechanisms. In this review, the general features and limitations of quadrupole ion traps are discussed followed by a description of representative ion trap studies of organic reaction mechanisms such as substitution, elimination, and acyl transfer reactions.

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“…As a result, there is a shift of the equilibrium toward the reactants due to a tem- perature increase. In special cases, even entropy effects were considered to be responsible for this trend [34]. These effects allow an additional suppression of cluster formation in the HP-SQCC without significant alteration of more exothermic ion molecule reactions.…”

Section: Ion Molecule Reactions In the Hp-sqccmentioning

confidence: 99%

“…This cluster undergoes ligand-switching reactions with water and oxygen, which are present in neon as residual gases (see Figure 9). It was noticed [17,34] that ions of half-sandwich metallocenes react with electron-donating ligands with rate constants that are inversely proportional to the ligand ionization energies (IEs). In general, bond energies are also inversely proportional to the ligand IEs.…”

Section: Ion Molecule Reactions In the Hp-sqccmentioning

confidence: 99%

The high-pressure segmented quadrupole collision cell (HP-SQCC) as an ion molecule reactor

Guo

Siu

Baranov³

2005

J. Am. Soc. Mass Spectrom.

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A high-pressure 20-segment quadrupole collision cell (HP-SQCC), which replaces a collision cell in a modified triple-quadrupole mass spectrometer is investigated in this work as an ion-molecule reactor with an inherent heat source. The highest working pressure achievable is 20 mTorr. The 20 quadrupole segments permit superimposition of linear axial electric field over the conventional quadrupole field in the radial direction. The axial and radial fields are employed to control ion temperature. Heat is transferred to the reactants through ion frictional heating. The HP-SQCC utilizes a combination of several physicochemical phenomena and an attempt is made to examine a range of ion-molecule reactions. Due to a sufficiently large number of reactive collisions, the reactor is used to promote sequential exothermic ion-molecule reactions. To characterize the performance of the HP-SQCC, the various ion-molecule reactions between the fragment ions of ferrocene ( on-molecule reactions have captured the fascination of mass spectrometrists for a number of decades and have been probed using a variety of instrumentation, including Fourier-transform ion cyclotron resonance spectrometry, ion-trap mass spectrometry, triplequadrupole mass spectrometry and the selected-ion flow tube technique [1]. The conventional triplequadrupole mass spectrometer is a less than perfect instrument for an examination of ion-molecule reactions due to the relatively low pressure achievable in its second quadrupole (Q 2 ), which restricts the number of ion-molecule collisions, and to the limited control of ion energy within Q 2 . Nevertheless, reactions that lead to novel products have been discovered; one such reaction is the ligand-exchange reaction between [Pb(CH 3 ; Pb 2ϩ had previously been described as to be among "a select group of doubly charged metal ions that will not form stable complexes in the gas phase with water" [3].Here we report the first ion-molecule reaction results obtained on a high-pressure 20-segment quadrupole collision cell (HP-SQCC) that functions as the Q 2 in a modified triple-quadrupole mass spectrometer. The highest working pressure achievable is 20 mTorr with neon, about 4 times higher than that achievable on a standard triple-quadrupole instrument. The 20 quadrupole segments permit superimposition of an axial electric field, typically linear, over the conventional quadrupole field in the radial direction [4][5][6]. The HP-SQCC was originally developed for ion-mobility measurements [5,7], where the goal is to maintain the drift field low enough that the ion temperature is not increased significantly. In this study, we are exploring the use of the HP-SQCC as an efficient apparatus for utilizing ion-molecule reactions as an analytical method. The axial and radial fields are employed to control the ion temperature.To characterize the performance of the HP-SQCC, we have elected to use as probes the various ionmolecule reactions between the fragment ions of ferrocene (Cp 2 Fe) as well as cobaltocene (Cp 2 Co) and neutra...

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Entropy effects in gas phase ion-molecule association reactions

Cited by 14 publications

References 45 publications

Reactions of C5H5M+ (M=Fe, Ni) with substituted thiophenes

Reactions of C5H5M+ (M=Fe, Ni) with substituted thiophenes

Quadrupole ion trap studies of fundamental organic reactions

The high-pressure segmented quadrupole collision cell (HP-SQCC) as an ion molecule reactor

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