Jp. Peng et al., Experimental and ab initio investigations of the kinetics of the reaction of H atoms with H2S, J PHYS CH A, 103(27), 1999, pp. 5307-5311
The rate constant k(1) for the H + H2S reaction has been measured from 298
to 598 K by the flash-photolysis resonance fluorescence technique, and the
results are summarized as k(1) = (6.6 +/- 0.9) x 10(-11) exp[(-11.2 +/- 0.4
) kJ mol(-1)/RT] cm(3) molecule(-1) s(-1)(1 sigma uncertainty in the parame
ters). The 95% confidence interval for k(1) is estimated as 20%. Combinatio
n with literature data reveals distinct curvature in the Arrhenius plot and
a combined expression for 190-2237 K is k(1) = 5.8(-3.8)(+11.1) x 10(-17)
T1.94+/-0.15 exp[(-455 +/- 67)/T] cm(3) molecule(-1) s(-1). The geometry, f
requencies, and energy of the transition state were investigated at up to t
he QCISD(T)/6-311+G(3df,2p) level of theory, and conventional transition st
ate theory with Eckart tunneling corrections gave good accord with experime
nt up to about 1000 K. Neglect of variational effects appears to lead to er
rors of up to a factor of 2 at 2000 K.