A kinetic study of the reactions of vanadium, iron, and cobalt with sulfur dioxide

Abstract

A kinetic study of the reactions of ground state V, Fe, and Co with SO2 is reported. V, Fe, and Co were produced by the 248 nm photodissociation of VCl4, ferrocene, and Co(C5H5)(CO)2, respectively, and were detected by laser-induced fluorescence. V + SO2 proceeds by an abstraction reaction with rate constants given by k=(2.33 +/- 0.57)x 10(-10) exp[-(1.14 +/- 0.19) kcal mol(-1)/RT] cm3 molecule(-1) s(-1) over the temperature range 296-571 K. Fe + SO2 was studied in the N2 buffer range of 10-185 Torr between 294 and 498 K. The limiting, low-pressure third-order rate constants are given by k(0)=(3.45 +/- 1.19)x 10(-30) exp[-(2.81 +/- 0.24) kcal mol(-1)/RT] cm6 molecule(-2) s(-1). Co + SO2 was studied in the CO2 buffer range of 5-40 Torr between 294 and 498 K. This reaction is independent of temperature over the indicated range and has a third-order rate constant of k0=(5.23 +/- 0.28)x 10(-31) cm6 molecule(-2) s(-1). Results of this work are compared to previous work on the Sc, Ti, Cr, Mn, and Ni + SO2 systems. The reaction efficiencies for the abstraction reactions depend on the ionization energies of the transition metal atoms and on the reaction exothermicities, and the reaction efficiencies of the association reactions are strongly dependent on the energies needed to promote an electron from a 4s2 configuration to a 4s1 configuration.

Spontaneous sulfur dioxide activation by Group V metal (V, Nb, Ta) atoms in excess argon at cryogenic temperatures

“…The appearance of SMO 2 À can also be expected. As mentioned before, SO 2 has a significant electron affinity, 15 and SO 2 À can accumulate in the process of laser ablating, which react with metal atoms to give SMO 2…”

“…[8][9][10] Interestingly, such mechanisms were also highlighted in more simplified systems, from which the dynamic behavior of selected reactant gases (O 2 , SO 2 , CO 2 , N 2 , N 2 O, NO) with various transition metal (TM) atoms at room temperature were investigated, and SO 2 was found to be generally more reactive than the other gases. [11][12][13][14][15] However, details on such reactions are still demanding especially for a persuasive profile of the reaction mechanism, from which we can get a deeper understanding of whether activation of the S-O bond proceeds through a simple complex or is kinetically facile toward bond breaking.…”

Applying a Nonspin-Flip Reaction Scheme to Explain for the Doublet Sulfide Oxides SMO2 Observed for the Reactions of SO2 with V(4F), Nb(6D), and Ta(4F)

“…Kinetic investigations have also been carried out on the reactions of this molecule with different transition metal atoms. Results emerging from those studies show that SO 2 is more reactive than other gases (O 2 , SO 2 , CO 2 , N 2 , N 2 O, and NO) in this kind of reactions [10][11][12][13][14]. e interaction of SO 2 with laser-ablated transition metal atoms in groups IV-VI of the periodic table has been investigated by IR spectroscopy under matrix-isolation conditions [15][16][17].…”