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On the formation of SF n – (n = 1–6) anions via a novel route and their properties
Author(s) -
Mane Rupali,
Mehrotra Nitin,
Maity Dilip K.,
Gupta Anit K.
Publication year - 2015
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.7225
Subject(s) - chemistry , dissociation (chemistry) , sputtering , fragmentation (computing) , mass spectrometry , ion , ab initio , analytical chemistry (journal) , molecule , density functional theory , bond dissociation energy , yield (engineering) , computational chemistry , nanotechnology , thin film , organic chemistry , materials science , chromatography , computer science , metallurgy , operating system
Rationale Sulfur hexafluoride (SF 6 ) being a potential greenhouse gas, coupled with its numerous applications, makes the study of the formation and fragmentation of SF 6 ‐based species important. The formation of SF 6 ‐based anionic species has been studied using the gas feed‐sputtering route and the mechanisms at play during the sputter‐ejection of guest molecule‐derived particles have also been probed. Methods Studies of the formation of SF n – (n = 1–6) anions were conducted from various surfaces (metal and compound) that were subjected to Cs + ion sputtering in the presence of SF 6 gas employing the gas feed‐cesium sputter technique. The anions generated were mass analyzed using a double‐focusing magnetic sector mass spectrometer. Quantum mechanical computations were performed to study the ground state structure and stability of neutral and negatively charged SF n (n = 1–6) systems applying density functional theory (DFT) and ab initio methods (MP2 and CC). Results This technique readily generated 32 SF n – (n = 1–6) anions for all sizes of 'n' with practicable yields. Mass spectrometric measurements of the yield of sputter‐ejected 32 SF n – (n = 1–6) anions reveal an oscillatory pattern as a function of 'n', with odd values of 'n' being relatively more abundant. The relative yield of 34 SF n – (n = 1–6) anions with respect to size was also measured albeit with low signal intensity. Also observed were F – , S – , F 2 – , 33 SF 5 – and 33 SF 6 – anionic species. The relevant electron affinity and bond dissociation energy (BDE) values were also computed. Conclusions Gas‐phase SF n – (n = 1–6) anions can be effectively generated by using the gas spray‐cesium sputter technique. Both experimental measurements and calculations indicate the existence of odd–even oscillations in the stability and electronic structure of the SF n (n = 1–6) systems. The highest yield recorded was for the sputter‐ejected SF 5 – species and this may be attributed to its 'superhalogen' anionic character coupled with the relatively favorable F 0 fragmentation pathway of sputtered SF 6 – . A signature pertaining to intact SF 6 – anion ejection is also observed. Copyright © 2015 John Wiley & Sons, Ltd.