Some Reactions of Ground-State (3P) and Electronically Excited (1D) Sulfur Atoms

Abstract

Articles you may be interested inAn experimental and computational study of the reaction of ground-state sulfur atoms with carbon disulfideThe systematic behavior of (6Li,d) groundstate transitions in the 1f2p shell AIP Conf.Reactions of S (3 P) and S (1D) have been studied by utilizing carbonyl sulfide photolysis as a source of both species. It has been shown that 46%±4% of the sulfur atoms generated in the photolysis of OCS in the 2250-2650-A spectral region can react as S (3 P), but that substantial portion of the S (3]') is likely produced by deactivating collisions of OCS molecules with S(ID). Both S(1D) and S(,1') react with CS,. The rate constant ratios for these reactions relative to the reactions with OCS have been determined as ~1.9 and ~2.4X102, respectively. Efficient isotopic exchange of S(3P) with CS2 is proposed to occur by means of CS3 formation in a reaction independent of pressure above 50 torr. The reaction of S (ID) with N20 yields N2, but kinetic complexities suggest the intermediate formation of a species such as N20S. Measurement of the quenching of the N2 yield has led to the determination of the relative rates of collisional deactivation of S(ID) for several gases.

Multiple-sulfur isotope effects during photolysis of carbonyl sulfide

“…For laboratory OCS photochemistry experiments employed in this study, photodissociation of OCS (Reaction R1) is followed by sulfur abstraction from OCS (Reaction R2) (Basco and Pearson, 1967;Breckenridge and Taube, 1970;Wiebe et al, 1964;Zhao et al, 1995):…”

“…During photolysis (R1), atomic sulfur is produced predominantly in S( 1 D) electronic state ( 1a = 0.74) because production of S( 3 P) is spin forbidden (Okabe, 1978;Sidhu et al, 1966;Breckenridge and Taube, 1970). Pseudofirst-order rate constants for Reactions (R2a), (R2b), and (R3) were estimated to be 5 × 10 −11 , 2.7 × 10 −15 , and 15 × 10 −11 cm 3 s −1 , respectively (Zhao et al, 1995;Lu et al, 2006).…”

“…is slow (second-order rate constant is about 10 −33 cm 6 s −1 ) (Du et al, 2008) and is only relevant if a high power UV source is used (Breckenridge and Taube, 1970). Because dissociation threshold through S( 1 D) channel (R1a) is (4.26 ± 0.1) eV or (291 ± 7) nm (Suzuki et al, 1998), photolysis of OCS with λ > 285 nm produces S 0 exclusively in the triplet state (Reaction R1b).…”

Production and IR Absorption of Cyclic CS2 in Solid Ar

“…Several authors investigated photolysis of SCS in the UV region. [39][40][41][42] Photodissociation at 193 nm proceeds via the 1 Σ u + ( 1 B 2 ) surface which leads to predissociation into CS and S:…”

Decomposing the First Absorption Band of OCS Using Photofragment Excitation Spectroscopy

“…41 Sulfur atoms are formed predominantly in the electronically excited 1 D state with a far smaller fraction produced in the 3 P ground state. Early measurements of the branching between singlet and triplet S atom photoproducts inferred that S( 1 D) accounted for around 75% of the total atomic sulfur yield, 6,43 although measurements in collisional environments were complicated by quenching. Two-photon LIF measurements by van Veen et al probed the timedependent formation of S( 3 P) and S( 1 D) atoms following photolysis at 248 nm.…”