Size-dependent gas phase reactivity of tantalum cluster cations with small alcohols

Abstract Small tantalum cluster cations (Ta 4–9 + ) were produced in the gas phase by laser vaporization. Various alcohols (methanol, ethanol, n -propanol and 2-propanol) were consecutively added to the cluster beam in a pulsed jet and allowed to react to an extent of conversion of approximately 50%. The charged reaction products were subsequently measured using time of flight mass spectrometry. Two distinct reaction pathways were observed, involving complete dehydrogenation or OH abstraction from the alcohol molecule. The relative total reaction yield was found to not vary significantly within the cluster size regime studied. The branching ratios for the reaction demonstrated a cluster-size dependence, with a minimum of OH abstraction occurring for Ta 7 + .