Temperature dependent rate constants for the reactions of gas phase lanthanides with N2O

The reactivity of gas phase lanthanide (Ln) atoms (Ln=La–Yb with the exception of Pm) with N2O from 298 to 623 K is reported. Lanthanide atoms were produced by the photodissociation of Ln(TMHD)3 (TMHD=2,2,6,6-tetramethyl-3,5-heptanato ion) and detected by laser-induced fluorescence. Large variations in the reaction rate constants are observed. The bimolecular rate constants are described in Arrhenius form by k[Ce(1G4)]=(1.9±0.5)×10−10 exp(−0.8±0.8 kJ mol−1/RT); Pr(4I9/2), (3.6±1.2)×10−10 exp(−8.0±1.2 kJ mol−1/RT); Nd(5I4), (3.4±0.4)×10−10 exp(−8.8±0.5 kJ mol−1/RT); Sm(7F0), (3.2±1.1)×10−10 exp(−11.2±1.2 kJ mol−1/RT); Eu(8S7/2), (2.7±0.4)±10−10 exp(−12.7±0.5 kJ mol−1/RT); Gd(9D2), (2.0±0.3)×10−10 exp(−6.4±0.5 kJ mol−1/RT); Tb(6H15/2), (2.9±0.5)×10−10 exp(−10.9±0.6 kJ mol−1/RT); Dy(5I8), (3.4±0.8)×10−10 exp(−16.2±0.8 kJ mol−1/RT); Ho(4I15/2), (2.9±0.5)×10−10 exp(−17.1±0.6 kJ mol−1/RT); Er(3H6), (3.3±1.2)×10−10 exp(−18.4±1.2 kJ mol−1/RT); Tm(2F7/2), (3.5±0.6)×10−10 exp(−19.5±0.6 kJ mol−1/RT); Yb(1S0), (2.5±0.2)×10−10 exp(−20.2±0.3 kJ mol−1/RT) where the uncertainties represent ±2σ. The reaction barriers are found to correlate to the energy required to promote an electron out of the 6s subshell.