Fig. 1. The transition structures of the hydrogen abstraction reactions of CF₂(³B₁) with (a) HX (X = H, F, Cl, Br), (b) H₂X (X = O, S), (c) XH₃ (X = N, P), and (d) XH₄ (X = C, Si).

Fig. 2. Calculated colvalent curve crossing heights, E_xn, (Eq. (5), with modified D₀ – see text) versus computed classical barrier for reactions CF₂(³B₁) + XH_n (n = 1 for X = H, Cl, Br, F; n = 2 for X = O and S, n = 3 for X = P and N; n = 4 for X = Si and C). The ordering of the various reactions along the x-axis is given at the top of the figure. The dotted line is an unweighted least-squares linear fit through the points.

Fig. 3. Calculated ionic curve crossing heights, E_xn, (Eq. (4)) versus computed classical barrier + ZPE for reactions CF₂(³B₁) + XH_n (n = 1 for X = H, Cl, Br, F; n = 2 for X = O and S, n = 3 for X = N; n = 4 for X = Si and C). Here IE of 10.5 eV for CHF₂ and an EA of −2.2 eV for CF₂(³B₁) was used. The ordering of the various reactions along the x-axis is given at the top of the figure.

Geometric parameters^a of the transition structure with C_s symmetry^b in the hydrogen abstraction reactions of CF₂(³B₁) with XH_n (n = 1–4, X = H, F, Cl, Br, O, S, N, P, C, Si) at CCSD(T)/6-311++G(d,p) level^c

CCSD(T) relative energies (in kcal mol⁻¹) of the reactants, transition states and products for the hydrogen abstraction reaction of CF₂(³B₁) with XH_n (n = 1–4, X = H, F, Cl, Br, O, S, N, P, C, Si)^a

The bond dissociation energies (in kcal/mol) of H–X (X = H, F, Cl, Br, OH, SH, NH₂, PH₂, CH₃ and SiH₃), fitted three-parameter Arrhenius-type expressions and the thermal rate constants k(T) at 298 and 800 K (in cm³ s⁻¹)^a