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Low‐energy electron interactions with tungsten hexacarbonyl – W(CO) 6
Author(s) -
Wnorowski K.,
Stano M.,
Matias C.,
Denifl S.,
Barszczewska W.,
Matejčík Š.
Publication year - 2012
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.6324
Subject(s) - chemistry , ion , electron , tungsten , electron ionization , electron spectrometer , dissociation (chemistry) , mass spectrometry , metastability , quadrupole mass analyzer , atomic physics , analytical chemistry (journal) , electron beam processing , cathode ray , ionization , physics , organic chemistry , chromatography , quantum mechanics
RATIONALE Low‐energy secondary electrons are formed when energetic particles interact with matter. High‐energy electrons or ions are used to form metallic structures from adsorbed organometallic molecules like W(CO) 6 on surfaces. We investigated low‐energy electron attachment to W(CO) 6 in the gas phase to elucidate possible reactions during surface modification. METHODS Two crossed electron/molecular beam setups were utilised: (i) a high‐resolution electron monochromator combined with a quadrupole mass spectrometer which was used for the measurement of relative cross sections as a function of the electron energy, and (ii) a double focusing mass spectrometer used for measurements of metastable decays of anions. RESULTS The study was performed in the electron energy range between ~0 and 14 eV. W(CO) 6 efficiently decomposed upon attachment of a low‐energy electron and no stable W(CO) 6 – anion was observed on mass spectrometric time scales. The transient negative ion formed lost instead sequentially CO ligands. The fragment anions W(CO) 5 – , W(CO) 4 – , W(CO) 3 – , and W(CO) 2 – were observed. However, no W – was detectable. CONCLUSIONS Dissociative electron attachment (DEA) to W(CO) 6 led to strong dissociation but a complete loss of all CO ligands was not observed in DEA. Deposit contaminations might be a direct result of DEA reactions close to the irradiation spot in beam deposition techniques. Copyright © 2012 John Wiley & Sons, Ltd.