Rate constant determination in the reaction of gold ion with carbonyl using single-atom chemistry in gas phase

The reactions of single gold ion Au+ with CO and H2O molecules in gas phase were studied by experiment and calculation. A reaction tube was connected to the end of the jet to destroy the supersonic state of the molecular beam and enhance the collisions between the laser-sputtered metal ions with gas molecules, so as to ensure the equilibrium reaction conditions. The ionic products were analyzed by a time-of-flight mass spectrometer. The collision temperature in reaction tube was calibrated to 409 K by the reaction of Au+ ion and H2O molecules. The contents of ionic products Au(CO)(+) and Au(CO)(2)(+) in the reaction of Au+ with CO molecules were monitored under different concentrations of CO in precursor gas. The combination reaction rate constants of single Au + ion sequentially with two CO molecules were determined to be k(1) = 1.1 (2) x 10(-12) cm(3)s(-1) and k(2) = 4.5 (5) x 10(-10) cm(3)s(-1). The geometric structures and binding energies of the ionic products, as well as the pathway and rate constants of the reactions were predicted by a high-level ab initial calculation. The binding mode of Au+ and CO and the formation of molecular orbital were discussed. (C) 2022 Published by Elsevier B.V.