Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Primary and secondary kinetic isotope effects in proton (H+/D+) and chloronium ion (35Cl(+)/37Cl(+)) affinities
Autore:
Gozzo, FC; Eberlin, MN;
Indirizzi:
Univ Estadual Campinas, Inst Chem, UNICAMP, BR-13083970 Campinas, SP, Brazil Univ Estadual Campinas Campinas SP Brazil BR-13083970 BCpinas, SP, Brazil
Titolo Testata:
JOURNAL OF MASS SPECTROMETRY
fascicolo: 10, volume: 36, anno: 2001,
pagine: 1140 - 1148
SICI:
1076-5174(200110)36:10<1140:PASKIE>2.0.ZU;2-E
Fonte:
ISI
Lingua:
ENG
Soggetto:
COLLISION-INDUCED DISSOCIATION; QUADRUPOLE MASS SPECTROMETERS; GAS-PHASE ACIDITIES; ELECTRON-AFFINITIES; CLUSTER IONS; THERMOCHEMICAL DETERMINATIONS; BOUND HETERODIMERS; ATTACHMENT SITES; BOND-ENERGIES; AB-INITIO;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Physical, Chemical & Earth Sciences
Citazioni:
44
Recensione:
Indirizzi per estratti:
Indirizzo: Eberlin, MN Univ Estadual Campinas, Inst Chem, UNICAMP, CP 6154, BR-13083970 Campinas,SP, Brazil Univ Estadual Campinas CP 6154 Campinas SP Brazil BR-13083970 BC
Citazione:
F.C. Gozzo e M.N. Eberlin, "Primary and secondary kinetic isotope effects in proton (H+/D+) and chloronium ion (35Cl(+)/37Cl(+)) affinities", J MASS SPEC, 36(10), 2001, pp. 1140-1148

Abstract

The Cooks' kinetic method and tandem-in-space pentaquadrupole QqQqQ mass spectrometry were used to measure primary and secondary kinetic isotope effects (KIEs) in H+ and Cl+ (X+) affinity for a series of A/A' isotopomeric pairs. Gaseous, isotopomeric, and loosely bound dimers [A...chi (+)...A] wereformed in combinations in which chi = H+, D+, Cl-35(+) or Cl-37(+) and A/A' = acetonitrile/acetonitrile-d(3), acetonitrile/acetonitrile-N-15, acetonitrile-d(3)/acetonitrile-N-15, acetone/acetone-d(6), acetone/acetone-O-18, acetone-d(6)/acetone-O-18, pyridine/pyridine-d(5), pyridine/pyridine-N-15, pyridine-d(5)/pyridine-N-15, or 3-(Cl-35)chloropyridine/3-(Cl-37) chloropyridine. Under nearly the same experimental conditions, the dimers were mass-selected and then dissociated by low-energy collisions with argon, yielding AX(+) and A'X+ as the fragment ions. KIEs were measured from the changes inion affinities of the neutrals (AXI) as estimated by the AX(+)/A'X+ abundance ratios. Using [A...H+(D+)... '] and [A...Cl-35(+)(Cl-37(+))...A'] dimers and by comparing their extent of dissociation tinder nearly identical collision-induced dissociation conditions, the kinetic method was also applied, for the first time, to measure primary KIEs of the central ion as well astheir influence on secondary KIEs. Becke3LYP/6311++G(2df,2p) calculations were found to provide Delta(Delta ZPE)s for the competitive dissociation reactions that accurately predict the nature (normal or inverse) of the measured KIEs. Copyright (C) 2001 John Wiley & Sons, Ltd.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 21:13:30