Measurement of the Rate Coefficient of the Reaction CO++ 2CO → CO+· CO + CO in a Drift-Tube Mass Spectrometer

The rate coefficient for the ion-molecule reaction C${\mathrm{O}}^{+}$ + 2CO → C${\mathrm{O}}^{+}$ · CO + CO was measured with a drift-tube mass spectrometer at a gas temperature of 300 °K. The range of $\frac{E}{N}$ which was covered extended from 75 to 150 Td. [Here $\frac{E}{N}$ is the ratio of the electrostatic-driftfield intensity to the gas number density and is measured in Townsend (Td), where 1 Td = ${10}^{-17\mathrm{}}$ V ${\mathrm{cm}}^2$.] The technique used to evaluate the rate coefficient was the comparison of detailed "arrival-time" profiles for the product ions with analytical solutions to the differential equation governing the motion of the ions. The measured values of the rate coefficient varied from a high of 1.35 × ${10}^{-28\mathrm{}}$ ${\mathrm{cm}}^6$/sec at an $\frac{E}{N}$ of 75 Td to 1.1 × ${10}^{-28\mathrm{}}$ ${\mathrm{cm}}^6$/sec for values of $\frac{E}{N}$ between 110 and 150 Td.