TY - JOUR
T1 - Importance of Shattering Fragmentation in the Surface-Induced Dissociation of Protonated Octaglycine
AU - Park, Kyoyeon
AU - Deb, Bipasha
AU - Song, Kihyung
AU - Hase, William L.
N1 - Funding Information:
The authors acknowledge that the research reported here is based on work supported by the National Science Foundation under grant no. CHE-0615321 and the Robert A. Welch Foundation under grant no. D-0005. W.L.H. acknowledges important conversations with Julia Laskin and Jean Futrell concerning SID.
PY - 2009/6
Y1 - 2009/6
N2 - A QM + MM direct chemical dynamics simulation was performed to study collisions of protonated octaglycine, gly8-H+, with the diamond {111} surface at an initial collision energy Ei of 100 eV and incident angle θi of 0° and 45°. The semiempirical model AM1 was used for the gly8-H+ intramolecular potential, so that its fragmentation could be studied. Shattering dominates gly8-H+ fragmentation at θi = 0°, with 78% of the ions dissociating in this way. At θi = 45° shattering is much less important. For θi = 0° there are 304 different pathways, many related by their backbone cleavage patterns. For the θi = 0° fragmentations, 59% resulted from both a-x and b-y cleavages, while for θi = 45° 70% of the fragmentations occurred with only a-x cleavage. For θi = 0°, the average percentage energy transfers to the internal degrees of freedom of the ion and the surface, and the energy remaining in ion translation are 45%, 26%, and 29%. For 45° these percentages are 26%, 12%, and 62%. The percentage energy-transfer to ΔEint for θi = 0° is larger than that reported in previous experiments for collisions of des-Arg1-bradykinin with a diamond surface at the same θi. This difference is discussed in terms of differences between the model diamond surface used in the simulations and the diamond surface prepared for the experiments.
AB - A QM + MM direct chemical dynamics simulation was performed to study collisions of protonated octaglycine, gly8-H+, with the diamond {111} surface at an initial collision energy Ei of 100 eV and incident angle θi of 0° and 45°. The semiempirical model AM1 was used for the gly8-H+ intramolecular potential, so that its fragmentation could be studied. Shattering dominates gly8-H+ fragmentation at θi = 0°, with 78% of the ions dissociating in this way. At θi = 45° shattering is much less important. For θi = 0° there are 304 different pathways, many related by their backbone cleavage patterns. For the θi = 0° fragmentations, 59% resulted from both a-x and b-y cleavages, while for θi = 45° 70% of the fragmentations occurred with only a-x cleavage. For θi = 0°, the average percentage energy transfers to the internal degrees of freedom of the ion and the surface, and the energy remaining in ion translation are 45%, 26%, and 29%. For 45° these percentages are 26%, 12%, and 62%. The percentage energy-transfer to ΔEint for θi = 0° is larger than that reported in previous experiments for collisions of des-Arg1-bradykinin with a diamond surface at the same θi. This difference is discussed in terms of differences between the model diamond surface used in the simulations and the diamond surface prepared for the experiments.
UR - http://www.scopus.com/inward/record.url?scp=65549089594&partnerID=8YFLogxK
U2 - 10.1016/j.jasms.2009.02.028
DO - 10.1016/j.jasms.2009.02.028
M3 - Article
C2 - 19318279
AN - SCOPUS:65549089594
SN - 1044-0305
VL - 20
SP - 939
EP - 948
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
IS - 6
ER -