Low‐energy electron interactions with tungsten hexacarbonyl – W(CO) 6

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.