Product distributions and isotopic selectivities in ir multiphoton dissociation of pentafluoroiodoethane

1981 ◽  
Vol 59 (9) ◽  
pp. 1307-1310 ◽  
Author(s):  
E. Weinberg ◽  
M. Gauthier ◽  
P. A. Hackett ◽  
C. Willis
Keyword(s):  
Reaction Mechanism ◽  
Bond Cleavage ◽  
Thermal Dissociation ◽  
Infrared Multiphoton Dissociation ◽  
High Fluence ◽  
Reaction Products ◽  
Product Distributions ◽  
Multiphoton Dissociation

Infrared multiphoton dissociation of pentafluoroiodoethane leads to a complex array of reaction products. For photolysis in the v4 band the reaction mechanism involves C2F5—I bond cleavage followed by thermal dissociation of C2F5 radicals. For irradiation within the v3 band at high fluence, efficient secondary photolysis of C2F5 radicals is postulated. At lower fluences the dissociation is isotopically selective leading to C4F10 enriched in carbon-13.

Characterization of Oligodeoxynucleotide Fragmentation Pathways in Infrared Multiphoton Dissociation and Electron Detachment Dissociation by Fourier Transform Ion Cyclotron Double Resonance

2009 ◽  
Vol 15 (2) ◽  
pp. 293-304 ◽  
Author(s):  
Jiong Yang ◽  
Kristina Håkansson
Keyword(s):  
Fourier Transform ◽  
Bond Cleavage ◽  
Double Resonance ◽  
Infrared Multiphoton Dissociation ◽  
Electron Detachment Dissociation ◽  
Electron Detachment ◽  
Fragmentation Pathways ◽  
Ion Cyclotron ◽  
Multiphoton Dissociation ◽  
Tandem Mass Spectrometric

Infrared multiphoton dissociation (IRMPD) is a vibrational excitation tandem mass spectrometric fragmentation method valuable for sequencing of oligonucleotides. For oligodeoxynucleotides, typical product ions correspond to sequence-specific 5′ ( a-base) and their complementary 3′ w-type ions from carbon–oxygen bond cleavage at the 3′ position of the deoxyribose from which a nucleobase is lost. Such fragmentation patterns are also observed in collision activated dissociation (CAD). The CAD oligodeoxynucleotide fragmentation mechanism has been characterized in detail. By contrast, fragmentation schemes in IRMPD have not been rigorously established. In this paper, we apply, for the first time, Fourier transform ion cyclotron double resonance (DR) experiments to characterize IRMPD fragmentation pathways of oligodeoxynucleotide anions. Our results suggest that neutral base loss precedes backbone fragmentation but that T-rich oligodeoxynucleotides fragment via a different mechanism, similar to the mechanisms proposed for CAD. We also extend the DR approach to characterize intermediates in electron detachment dissociation of hexamer oligodeoxynucleotides. Here, we found that charge reduced radical precursor ions constitute major intermediates for dT6, d(GCATAC) and d(GCATGC). Furthermore, ( a/ z–T) ions ( z ions correspond to C–O bond cleavage on the other side of a backbone phosphate group as compared to the formation of a ions) mainly originate from secondary fragmentation of a/ z radical ions for the oligodeoxynucleotide dT6.

The Chemistry of Vulcanization. V. Action of 2,2′-Benzothiazolyl Disulfide on the Reaction of Diphenylmethane and Sulfur

1958 ◽  
Vol 31 (4) ◽  
pp. 788-799 ◽  
Author(s):  
Jitsuo Tsurugi ◽  
Haruko Fukuda
Keyword(s):  
Activation Energy ◽  
Zinc Oxide ◽  
Reaction Mechanism ◽  
Rate Equation ◽  
Thermal Dissociation ◽  
Material Balance ◽  
Reaction Products ◽  
Kcal Mole ◽  
Near Future

Abstract The reaction involving diphenylmethane, sulfur and 2,2′-benzothiazoIyl disulfide is summarized as follows. A. The reaction products and material balance among them are indicated. B. A reaction mechanism was decided upon. C. The rate equation for MBTS consumption was derived from the above mechanism and the results interpreted satisfactorily. The activation energy for thermal dissociation of 2,2′-benzothiazolyl disulfide was found to be 32.7 kcal/mole. D. The accelerating efficiency of this accelerator was defined, discussed and evaluated. These studies are being continued and further communications on the studies of accelerators in the presence of zinc oxide or zinc soap will appear in the near future.

Chloroform Infrared Multiphoton Dissociation in the Presence of O2 and NO2¶

2005 ◽  
Vol 81 (4) ◽  
pp. 789 ◽  
Author(s):  
V. Mariana Freytes ◽  
Jorge Codnia ◽  
M. Laura Azcárate
Keyword(s):  
Infrared Multiphoton Dissociation ◽  
Multiphoton Dissociation

Amplification of Infrared Multiphoton Dissociation Efficiency in a Quadruple Ion Trap Using IR-Active Ligands

2006 ◽  
Vol 78 (24) ◽  
pp. 8512-8517 ◽  
Author(s):  
Michael Pikulski ◽  
Jeffrey J. Wilson ◽  
Apolonio Aguilar ◽  
Jennifer S. Brodbelt
Keyword(s):  
Ion Trap ◽  
Infrared Multiphoton Dissociation ◽  
Dissociation Efficiency ◽  
Multiphoton Dissociation

Interrogation of N-Linked Oligosaccharides Using Infrared Multiphoton Dissociation in FT-ICR Mass Spectrometry

2006 ◽  
Vol 78 (14) ◽  
pp. 4990-4997 ◽  
Author(s):  
Katherine S. Lancaster ◽  
Hyun Joo An ◽  
Bensheng Li ◽  
Carlito B. Lebrilla
Keyword(s):  
Mass Spectrometry ◽  
Infrared Multiphoton Dissociation ◽  
Multiphoton Dissociation ◽  
Ft Icr
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