Kinetic study of gas-phase Y(a2D3/2) and La(a2D3/2) with O2, N2O, CO2 and NO

The second-order rate constants of gas-phase Y(a(2)D(3/2)) and La(a(2)D(3/2)) with O-2, N2O, CO2 and NO as a function of temperature are reported. In all cases, the reactions are relatively fast. For Y(a(2)D(3/2)), the bimolecular rate constants (in cm(3) s(-1)) are described in Arrhenius form by k(O-2) = (2.2 +/- 0.1) X 10(-10) exp(-3.5 +/- 0.6 kJ mol(-1)/RT), k(N2O) = (1.9 +/- 0.2) X 10(-10) exp( -4.0 +/- 0.8 kJ mol(-1)/RT), k(CO2) = (1.0 +/- 0.1) x 10(-10) exp(-2.3 +/- 0.6 kJ mol(-1)/RT), where the uncertainties are +/-2 sigma. The rate constants for Y reacting with NO are temperature insensitive with a value of 1.0 X 10(-10) cm(3) s(-1). For La(a(2)D(3/2)), the bimolecular rate constants for all the reactants are near the gas-kinetic collision rate. (C) 1998 Published by Elsevier Science B.V. All rights reserved.