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Abstract

The self-rigidification of ionized π-conjugated systems based on two combinations of thiophene (T) and 3,4-Ethylenedioxythiophene (E) is investigated using mass-analyzed ion kinetic energy spectrometry (MIKES) of ions produced from electron impact ionization at 70 eV. The m/z 446 radical cations of the two isomers ETTE and TEET lead to detect m/z 418 and 390 daughter ions. The MIKE spectra differ only by the intensities of these fragment ions. As the m/z 418 daughter ion is produced through a same retro-Diels Alder reaction whatever the fragmenting isomer, the difference in daughter ion intensities is interpreted in term of unimolecular dissociation rate constants (k(E_int)) ratios. Considering that the transition state (TS) of such reaction is attributed to a quinoid form, equivalent vibration modes are assumed for the TS of both dissociating ETTE and TEET radical cations. As a result, by using the Rice–Ramsperger–Kassel–Marcus (RRKM) theory, the difference in daughter ion intensities is interpreted by considering that the fragmenting ion is more or less ordered in its ground state than at the transition state, resulting from the influence of the number of the S^…O interactions in the planarization of the TEET ion toward the ETTE charged species. The comparison of this behavior in MIKES experiments is supported by the modeling of ion behavior in mass spectrometer and the calibration in internal energy of the radical cations produced in an EI source.

Keywords

Conjugated systems oligothiophenes RRKM MIKES unimolecular dissociations

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References

Roncali

. Conjugated poly(thiophenes): synthesis, functionalization, and applications. Chem Rev 1992; 92: 711.

Roncali

. Molecular engineering of the band gap of π-conjugated systems: facing technological applications. Macromol Rapid Commun 2007; 28: 1761.

Cheng

Y-J

Yang

S-H

Hsu

C-S

. Synthesis of conjugated polymers for organic solar cell applications. Chem Rev 2009; 109: 5868.

Groenendaal

Jonas

Freitag

et al.

Poly(3,4-ethylenedioxythiophene) and its derivatives: past, present, and future. Adv Mater 2000; 12: 481.

Turbiez

Blanchard

et al.

Mixed p-conjugated oligomers of thiophene and 3,4-ethylenedioxythiophene (EDOT). Tetrahedron Lett 2000; 41: 5521.

Raimundo

J-M

Blanchard

Frère

et al.

Push–pull chromophores based on 2,2′-bi(3,4-ethylenedioxythiophene) (BEDOT) π-conjugating spacer. Tetrahedron Lett 2001; 42: 1507.

Roncali

Blanchard

Frère

. 3,4-Ethylenedioxythiophene (EDOT) as a versatile building block for advanced functional π-conjugated systems. J Mater Chem 2005; 15: 1589.

Turbiez

Frère

Allain

et al.

Design of organic semiconductors: tuning the electronic properties of pi-conjugated oligothiophenes with the 3,4-ethylenedioxythiophene (EDOT) building block. Chem Eur J 2005; 11: 3742.

Mc Lafferty

Turecek

. Interpretation of mass spectra, 4th ed. Sausalito, CA: University Science Books, 1993.

10.

Drahos

Vékey

. MassKinetics: a theoretical model of mass spectra incorporating physical processes, reaction kinetics and mathematical descriptions. J Mass Spectrom 2001; 36: 237.

11.

Marcus

Rice

. The kinetics of the recombination of methyl radicals and iodine atoms. J Phys Chem 1951; 55: 894.

12.

Rosenstock

Wallenstein

Wahrhaftig

et al.

Absolute rate theory for isolated systems and the mass spectra of polyatomic molecules. Proc Natl Acad Sci USA 1952; 38: 667.

13.

Beyer

Swinehart

. Algorithm 448: number of multiply-restricted partitions. Commun ACM 1973; 16: 379.

14.

Vékey

. Internal energy effects in mass spectrometry. J Mass Spectrom 1996; 31: 445.

15.

Baer

Mayer

. Statistical Rice-Ramsperger-Kassel-Marcus quasiequilibrium theory calculations in mass spectrometry. J Am Soc Mass Spectrom 1997; 8: 103–115.

16.

Baer

Hase

. Unimolecular reaction dynamics: theory and experiments, Oxford, NY: Oxford University Press, 1996.

17.

Holmes

Aubry

Mayer

. Proton affinities of primary alkanols: an appraisal of the kinetic method. J Phys Chem A 1999; 103: 705–709.

18.

Robinson

Holbrook

. Unimolecular reactions, Chichester, UK: Wiley-Interscience, 1972.

19.

Cooks

Lester

Caprioli

et al.

Metastable ions, Amsterdam, NL: Elsevier Scientific Publishing Campagny, 1973.

20.

Naban-Maillet

Lesage

Bossée

et al.

Internal energy distribution in electrospray ionization. J Mass Spectrom 2005; 40: 1.

21.

Pak

Lesage

Gimbert

et al.

Internal energy distribution of peptides in electrospray ionization: ESI and collision-induced dissociation spectra calculation. J Mass Spectrom 2008; 43: 447.

22.

Rondeau

Galland

Zins

E-L

et al.

Non-thermal internal energy distribution of ions observed in an electrospray source interfaced with a sector mass spectrometer. J Mass Spectrom 2011; 46: 100.

23.

Ichou

Lesage

Machuron-Mandard

Junot

Cole

Tabet

J-C

. Collision cell pressure effect on CID spectra pattern using triple quadrupole instruments: a RRKM modeling. J Mass Spectrom 2013; 48: 179.

24.

Rondeau

Drahos

Vékey

. Internal energy distribution in electrospray ionization: towards the evaluation of a thermal-like distribution from the multiple-collision model. Rapid Commun Mass Spectrom 2014; 28: 127.

25.

Gatineau

Memboeuf

Milet

et al.

Experimental bond dissociation energies of benzylpyridinium thermometer ions determined by threshold-CID and RRKM modeling. Int J Mass Spectrom 2017; 417: 69.

26.

Gömöry

Végh

Sztáray

et al.

Kinetic energy release of protonated methanol clusters using the low-temperature fast-atom bombardment: experiment and theory combined. Eur J Mass Spectrom 2004; 10: 213.

27.

Drahos

Sztáray

Vékey

. Theoretical calculation of isotope effects, kinetic energy release and effective temperatures for alkylamines. Int J Mass Spectrom 2003; 225: 233.

28.

Nacson

Harrison

. Energy transfer in collisional activation. Energy dependence of the fragmentation of n-alkylbenzene molecular ions. Int J Mass Spectrom Ion Process 1985; 63: 325.

29.

Baer

Dutuit

Mestdagh

et al.

Dissociation dynamics of n-butylbenzene ions: the competitive production of m/z 91 and 92 fragment ions. J Chem Phys 1988; 92: 5674.

30.

Dawson

. Low-energy collision-activated dissociation of n-butylbenzene. Effect of the electron energy used during parent ion formation. Int J Mass Spectrom Ion Process 1985; 63: 339.

31.

Plomley

Londry

March

. The consecutive fragmentation of n-butylbenzene in a quadrupole ion trap. Rapid Commun Mass Spectrom 1996; 10: 200.

32.

Muntean

Armentrout

. Modeling kinetic shifts for tight transition states in threshold collision-induced dissociation. Case study: phenol cation. J Phys Chem B 2002; 106: 8117.

33.

Frisch

Trucks

Schlegel

et al.

Gaussian 09, Revision D.01, Wallingford, CT: Gaussian, Inc, 2009.

34.

Stephens

Devlin

Chablowski

et al.

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields. J Phys Chem 1994; 98: 11623 and references cited therein.

35.

Hehre

Ditchfield

Pople

. Self-consistent molecular orbital methods. XII. Further extensions of Gaussian—type basis sets for use in molecular orbital studies of organic molecules. J Chem Phys 1972; 56: 2257.

36.

Beno

Wilsey

Houk

. The C₇H₁₀ potential energy landscape: concerted transition states and diradical intermediates for the Retro-Diels−Alder reaction and [1,3] sigmatropic shifts of norbornene. J Am Chem Soc 1999; 121: 4816.

37.

Ovcharenko

Shaikhutdinov

Pihlaja

et al.

Mass-spectrometric differentiation of diexo- and diendo-fused isomers of norbornane/ene-condensed 2-thiouracil and 1,3-thiazino[3,2-a]pyrimidine derivatives: stereoselectivity of retro-diels-alder fragmentations under EI and CI conditions. J Am Soc Mass Spectrom 2001; 12: 1011.

38.

Lim

Schultz

Gislason

et al.

Activation energies for the fragmentation of thiophene ions by surface-induced dissociation. J Phys Chem B 1998; 102: 9362.

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Mass spectrometry evidence for self-rigidification of π-conjugated oligomers containing 3,4-ethylenedioxythiophene groups using RRKM theory and internal energy calibration

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