PRESSURE-DEPENDENCE OF THE REACTION OF 1-BUTANETHIOL WITH HYDROGEN-ATOMS

The reaction of 1-butanethiol with hydrogen atoms was investigated at room temperature under pressures of 133, 266, 532, 2660, and 5320 Pa, using two types of fast-flow discharge reactors; the main products wer e n-butane and 1-butene with total yields of more than 90%. In the rea ction of 1-butanethiol and deuterium atoms, monodeuterated 1-butanethi ol was observed by a photo-ionizing mass spectrometer. The relative ra te of the two initial reactions of 1-butanethiol with hydrogen atoms w as 0.272 (k(1)/k(2)). The n-butane and 1-butene are considered to be p roduced via chemically activated 1-butanethiol on the basis of the pre ssure dependence of the two main products. 1-C4H9SH + H --> 1-C4H9 . H2S (1) 1-C4H9SH + H --> 1-C4H9S . + H-2 (2) 1-C4H9S . + H --> 1-C4H9 SH (3) Relative rates of molecular elimination of hydrogen sulfide an d C-S bond fission for the chemically activated 1-butanethiol, k(5)/k( 4) and k(6)/k(4), were 0.114 and 0.0552 under 532 Pa of pressure at ro om temperature. Activation energies of the two reactions were calculat ed to be 228 [kJ/mol] and 297 [kJ/mol], respectively, by use of RRKM o n the base of estimated A factors. 1-C4H9SH + M --> 1-C4H9SH (4) 1-C4 H9SH --> 1-C4H8 + H2S (5) 1-C4H9SH* --> 1-C4H9. + HS . (6) (C) 1998 J ohn Wiley & Sons, Inc.