Reactivity of the cyclohexane ion

Sieck, L. Wayne; Searles, S. K.; Rebbert, R. E.; Ausloos, P.

doi:10.1021/j100715a022

Cited by 23 publications

(20 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Quantitative experiments could not be carried out at higher pressures due to the complexity of the com· po site mass spectrum under those conditions. Analogous experiments with i-C 4Ds gave the same overaU result [12], although the sum of CSOi6 and CSOi4 was approximately 0.5 at 50 millitorr. The observation of this reaction sequence accounts for the large ionic yields of isobutane obtained previously in the photo· ionization and radiolysis of isobutene·Oz mixtures in closed systems.…”

Section: 6 Collisional Stabilization Of Cshis*supporting

confidence: 51%

Photoionization of C4H+8 isomers. Unimolecular and biomolecular reactions of C4H+8 ions

Sieck¹,

Lias²,

Hellner³

et al. 1972

J. RES. NATL. BUR. STAN. SECT. A.

Self Cite

View full text Add to dashboard Cite

l·But e ne, cis·2·butene, iso bute ne a nd me lh ylcyclop ropa ne have bee n ph Oloioni ze d with th e reso nan ce lin es of krypton (10.0-10.6 eV) a nd argo n (11.6-11 .8 eV). We have de te rmin ed th a t th e intern aliy exc ite d ].C" H'; ion a nd , to a mu c h lesse r ex te nl , th e i,C4 l:-~+ ion iso me ri zes to th e 2 , C4 H~ stru c ture. In both cases th e ex te nt of iso me ri za ti on in c reases , approx imatel y by a fa c tor of len whe n th e photon e ne rgy is in creased from 10 to 11.7 e V. An in e rt gas, neo n, qu enc hes the iso me ri zati on of th e i-c', Hit ion and , 10 a mu c h lesse r rex te nt , Ih a t of th e l ·C H; ion .Th e unim olec ul a r fragme ntation of th e C.,H s iso me ri c ions has bee n exa min ed a t 11.6-11.8 eV.In · thi s e ne rgy range th e d issoc ia tive li fe tim e of i·C,H '; wa s found to be a tl eas t S X 10-'; s, a nd colli s iona l qu e nc hing of Ih e di ssoc iative process is a lready noti ceab le at press ures in th e 10-" torr ran ge.Th e rate coe ffi cie nts fo r th e reaction c'1 Hs (th e rm al) + c', H s -> (C.I:-I 16)* occ urrin g in th e iso me ri c C. H8 sys te ms have bee n de te rmin ed und er conditi ons w here th e s tru c ture of th e reac tin g C,I H; ion is es tabli s hed. Th e va lu es in c m "/ mo lec ul e ' seco nd a re 1·C. H 8-6. 0 ± 0.S x 10-'°, cis·2·C. Hs-0. 37 ± O.l X 10 -'°, i·C 4Hs -S.4± 0.4 X 10-'°. At press ure bel o w 10 -" torr , th e inte rn a ll y exc ited (Cs I:-I ,'.)* produ ced in th e reac tion di ssoc iates a long variou s c ha nn e ls with re la tiv e probabilities depe nd in g upon th e s tru cture of both the ioni c a nd ne utra l reactant. Above 10 -" torr colli s ional qu e nc hin g of (C 8I:-1 ,\)* is noted.Key words: C" Hs iso me rs; colli sional s ta bili zation; iso m e ri zation; photoion izat ion : rate co ns ta nts; vapo r Il hase.

show abstract

Section: 6 Collisional Stabilization Of Cshis*supporting

confidence: 51%

Photoionization of C4H+8 isomers. Unimolecular and biomolecular reactions of C4H+8 ions

Sieck¹,

Lias²,

Hellner³

et al. 1972

J. RES. NATL. BUR. STAN. SECT. A.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These reactions are similar to those observed by Sieck and Searles in a non-resonant continuous photoionization HPMS. 24 They studied the reactions of alkane molecular cations with water and found that the parent ions from cy-a͒ Author to whom correspondence should be addressed. clohexane, cyclopentane, i-butane, n-butane, i-pentane, n-pentane and n-hexane react exclusively via a termolecular mechanism involving two water molecules to produce a protonated water dimer.…”

Section: Introductionmentioning

confidence: 99%

Termolecular proton transfer reactions assisted by ionic hydrogen bond formation: Reactions of aromatic cations with polar molecules

Daly

Meot‐Ner

Pithawalla

et al. 1996

The Journal of Chemical Physics

View full text Add to dashboard Cite

We present a new method that applies resonant-two-photon ionization to generate reactant ions selectively in the source of a high-pressure mass spectrometer (R2PI-HPMS) for kinetic and equilibrium studies. Applications to reactions that would be obscured otherwise in a complex system are illustrated in mixtures of benzene with polar solvent molecules (S). We observe a novel type of proton transfer reactions from C6H6+• to two S molecules where S=CH3CN, CH3OH, C2H5OH and CH3COOC2H5, and from C6H5CH3+• to two S molecules where S=CH3OH and C2H5OH to form protonated solvent S2H+ dimers. The reactions are driven by the strong hydrogen bonds in the S2H+ dimers and therefore require the formation of the hydrogen bond concertedly with proton transfer, to make the process energetically feasible. The adducts (C6H6+•)S are observed with blocked solvent molecules where the subsequent switching reaction to yield S2H+ is slow, but not with alcohol reactants that can form hydrogen-bonded chains that facilitate fast subsequent proton extraction. Correspondingly, kinetic simulations suggest that the mechanism proceeds through (C6H6+•)S+S→S2H++C6H5• and C6H6+•+2S→S2H++C6H5• reactions, respectively. The rate coefficients of these reactions are in the range 10−13−10−12 cm3 s−1 for the reaction through a bimolecular switching channel and in the range 10−26−10−28 cm6 s−1 for reaction through a direct termolecular proton extraction mechanism. The relation to energetics and reactant structure is examined.

show abstract

“…Relative values reproducible to within an error limit of &4%. Beauchamp et al [ l l ] have reported a value of 0.55X lo-'* cm3/molecule-sec for process (5) using electron impact ionization of CH3Br at 11.4 eV. Other aspects of the data will be considered in the Discussion.…”

Section: A Methyl Halidesmentioning

confidence: 92%

“…Following their initial discovery, Hamill and coworkers [2,3] also reported the formation of (C2H5Br)2+ in C2H5Br and (C&71)2+ in n-C&?I. Although since that time "persistent" collision complexes have been reported for a great variety of organic and inorganic systems, detection of stabilized dimeric parent ions in other vapor-phase organic stystems (excluding condensation ions in olefins) has been restricted to ionized ethane [4], propane [5], isobutane [6], and benzene [7].…”

Section: Introductionmentioning

confidence: 99%

Formation of association ions in the photoionization of alkyl halides

Sieck

Gorden

1973

Int J of Chemical Kinetics

View full text Add to dashboard Cite

The methyl and ethyl chlorides and bromides, as well as methyl iodide, were photoionizcd in the vacuum ultraviolet at 300 K in a mass spectrometer over the pressure range 0.5 to approximately 100 millitorr. Under these conditions, stabilized parent ion dimers are found in CHaBr, CHBI, and C2H5Br, but not in the chlorides. Lower limits for the dissociative lifetimes of the ion-molecule collision complexes were estimated and are as follows: (CH3Br)z+, 1.6 ps; (CH31)2+, 1.9 p s ; and (CZHSBr)2+, 5.4 p s . An increase in photon energy (internal energy content of the reactant ion) decreases the dissociative lifetime of the collision complex in CHaI.

show abstract

Reactivity of the cyclohexane ion

Cited by 23 publications

References 0 publications

Photoionization of C4H+8 isomers. Unimolecular and biomolecular reactions of C4H+8 ions

Photoionization of C4H+8 isomers. Unimolecular and biomolecular reactions of C4H+8 ions

Termolecular proton transfer reactions assisted by ionic hydrogen bond formation: Reactions of aromatic cations with polar molecules

Formation of association ions in the photoionization of alkyl halides

Contact Info

Product

Resources

About