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001-es BibID:BIBFORM064081
Első szerző:Nagy Lajos (vegyész)
Cím:Can Nonpolar Polyisobutylenes be Measured by Electrospray Ionization Mass Spectrometry? Anion-Attachment Proved to be an Appropriate Method / Lajos Nagy, Tibor Nagy, György Deák, Ákos Kuki, Mihály Purgel, Mijid Narmandakh, Béla Iván, Miklós Zsuga, Sándor Kéki
Dátum:2016
ISSN:1044-0305 1879-1123
Megjegyzések:Polyisobutylenes (PIBs) with different end-groups including chlorine, exoolefin,hydroxyl, and methyl prepared from aliphatic and aromatic initiators werestudied by electrospray ionization mass spectrometry (ESI-MS). Independently ofthe end-groups, presence or absence of aromatic initiator moiety, these PIB derivativeswere capable of forming adduct ions with NO3? and Cl? ions, thus allowing thedirect characterization of these compounds in the negative ion mode of ESI-MS. Toobtain [PIB + NO3]? and [PIB + Cl]? adduct ions with appreciable intensities, additionof polar solvents such as acetone, 2-propanol, or ethanol to the dichloromethanesolution of PIBs was necessary. Furthermore, increasing both the polarity (by increasingthe acetone content) and the ion-source temperature give rise to enhancedintensities for both [PIB + NO3]? and [PIB + Cl]? ions. Energy-dependent collision induced dissociation studies(CID) revealed that increasing the collision voltages resulted in the shift of the apparent molecular masses tohigher ones. CID studies also showed that dissociation of the [PIB + Cl]? ions requires higher collision energythan that of [PIB + NO3]?. In addition, Density Functional Theory calculations were performed to gain insights intothe nature of the interactions between the highly non-polar PIB chains and anions NO3? and Cl? as well as todetermine the zero-point corrected electronic energies for the formation of [PIB + NO3]? and [PIB + Cl]? adductions.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
ESI-MS
Polyisobutylenes
Nitrated adduct ions
Chlorinated adduct ions
Tandem mass spectrometry
Megjelenés:Journal Of The American Society For Mass Spectrometry. - 27 : 3 (2016), p. 432-442. -
További szerzők:Nagy Tibor (1988-) (vegyész) Deák György (1954-) (polimer kémikus) Kuki Ákos (1966-) (villamosmérnök) Purgel Mihály (1982-) (vegyész) Narmandakh, Mijid Iván Béla Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Pályázati támogatás:TÁMOP-4.2.2.C-11/1/KONV-2012-0010
TÁMOP
K-101850
OTKA
Internet cím:Szerző által megadott URL
DOI
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001-es BibID:BIBFORM010304
Első szerző:Nagy Lajos (vegyész)
Cím:Dopant-Assisted Atmospheric Pressure Photoionization Mass Spectrometry of Polyisobutylene Derivatives Initiated by Mono- and Bifunctional Initiators / Lajos Nagy, Viktória Pálfi, Mijid Narmandakh, Ákos Kuki, Andrea Nyíri, Béla Iván, Miklós Zsuga, Sándor Kéki
Dátum:2009
Megjegyzések:Nine polyisobutylene (PIB) derivatives with different end groups (chlorine, vinyl, isobutenyl, 2,2-diphenylvinyl, and carboxyl) and molecular weights (1000 to 4500 g/mol), initiated by monofunctional and aromatic bifunctional initiators were studied by atmospheric pressure photoionization mass spectrometry (APPI-MS) in both the negative and the positive ion modes. Consistent with previous findings, negative ion APPI-MS revealed end-group identities through the formation of PIB adducts with chloride ions formed in situ from a chlorinated solvent (e.g., CCl4) in the presence of a dopant (toluene). In positive ion mode, considerable fragmentation of these PIB derivatives was observed, rendering end-group determinations very difficult. The Mn values obtained by APPI(-)-MS were considerably lower than those determined by SEC for PIB derivatives with Mn higher than 2000 g/mol. PIBs containing carboxyl termini can undergo collision-induced dissociation, yielding structurally important product ions. The resulting APPI-MS/MS intensities were found to reflect the "arm-length" distribution for PIBs with bifunctional aromatic moieties. In positive ion mode, [M+COCl]+ adducts were observed for PIBs with an aromatic initiator moiety. The origin of the COCl+ species is also discussed.
Tárgyszavak:Természettudományok Kémiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Polyisobutylene
APPI-MS
mass spectrometry
chloride ion attachment
Megjelenés:Journal of the American Society for Mass Spectrometry. - 20 : 12 (2009), p. 2342-2351. -
További szerzők:Pálfi Viktória Narmandakh, Mijid Kuki Ákos (1966-) (villamosmérnök) Nyíri Andrea Iván Béla Zsuga Miklós (1944-) (polimer kémikus) Kéki Sándor (1964-) (polimer kémikus)
Internet cím:DOI
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