Academic Journal

Experimental Bond Dissociation Energies of Benzylpyridinium Thermometer Ions determined by Threshold-CID and RRKM modeling

التفاصيل البيبلوغرافية
العنوان: Experimental Bond Dissociation Energies of Benzylpyridinium Thermometer Ions determined by Threshold-CID and RRKM modeling
المؤلفون: Gatineau, David, Memboeuf, Antony, Milet, Anne, Cole, Richard, B, Dossmann, Héloïse, Gimbert, Yves, Lesage, Denis
المساهمون: Institut Parisien de Chimie Moléculaire (IPCM), Chimie Moléculaire de Paris Centre (FR 2769), École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris Sciences et Lettres (PSL)-Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris Sciences et Lettres (PSL)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Département de Chimie Moléculaire (DCM), Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes 2016-2019 (UGA 2016-2019 ), Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Université de Brest (UBO)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)
المصدر: ISSN: 1387-3806.
بيانات النشر: CCSD
Elsevier
سنة النشر: 2017
المجموعة: Université Grenoble Alpes: HAL
مصطلحات موضوعية: Bond dissociation energies, Collision-induced dissociation, Energy-resolved mass spectrometry, Benzylpyridinium salts, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
الوصف: International audience ; Benzylpyridinium salts (BPs) have often been used as thermometer ions to obtain an energy calibration of mass spectrometric experiments (in particular to determine internal energy distributions of ions after the ionization process). Fragmentation of BP + molecular ions is characterized by specific Bond Dissociation Energies (BDE) which depend on the substituent group and its location on the benzyl ring. Although those BDE values are regularly re-evaluated by quantum chemical calculations, their experimental determination is still missing from the literature. In this paper, a modified Quadrupole-hexapole-Quadrupole (QhQ) mass spectrometer is used to obtain such values on 4 BP + molecular ions (characterized by a wide range of C-N bond strengths) using Threshold Collision-Induced Dissociations (TCID) and Rice-Ramsperger-Kassel-Marcus (RRKM) kinetic modeling. It is found that experimental values are systematically 0.5 eV lower than their most recent theoretical evaluations. Despite this shift, the absolute critical energy values are maintained in the same order (pOMe < pMe < pCl < pCN), and the relative energy differences are in very good agreement. We argue that the observed 0.5 eV shift relates to the energy dependence of the Transition State's number of states that is typical for barrier-less fragmentation processes and, relates to a kinetic rather than an energetic bottleneck. Notably, by taking into account the bond elongations characterizing the transition states and their corresponding calculated critical energies (E0), close agreement is found with experimentally obtained E0 values. We thus conclude that much care should be taken when describing the transition state during an internal energy calibration procedure where the involved energy is lower than 3-4 eV.
نوع الوثيقة: article in journal/newspaper
اللغة: English
DOI: 10.1016/j.ijms.2017.03.002
الاتاحة: https://hal.science/hal-03146746
https://hal.science/hal-03146746v1/document
https://hal.science/hal-03146746v1/file/IJMS_Fin.pdf
https://doi.org/10.1016/j.ijms.2017.03.002
Rights: info:eu-repo/semantics/OpenAccess
رقم الانضمام: edsbas.7905D83A
قاعدة البيانات: BASE
الوصف
DOI:10.1016/j.ijms.2017.03.002