Gas-Phase Reactions of Homo- and ... - Institut für Chemie

kinetic modeling with the ratios H 2, HD, and D 2 for Fe ‡ 2 and FeCo ‡ (Model 1) and for
Ni ‡ 2 ,Co ‡ 2 , FeNi ‡ , and CoNi ‡ (Model 2) are given by Eqns. 24 ± 29, respectively.
Model 1:
HD ˆ f 1;1
Helvetica Chimica Acta ± Vol. 88 (2005) 1411
Table 3. Isotopic Patterns for the Dehydrogenation of Pentanenitrile by Fe ‡ 2 ,Co ‡ 2 ,Ni ‡ 2 , FeCo ‡ , FeNi ‡ , and CoNi ‡a )
H 2 HD D 2 H 2 HD D 2 H 2 HD D 2
Exp. Model 1 Model 3
11a/Fe ‡ 2 27 6310 29.8 59.5 10.7 27.6 62.5 9.9
11b/Fe ‡ 2 59 41 55.2 44.30.5 58.7 40.9 0.4
11c/Fe ‡ 2 90 10 89.2 10.4 0.4 89.5 10.0 0.5
11d/Fe ‡ 2 90 10 89.2 10.4 0.4 89.5 10.0 0.5
1.6/4.3 c ) 0.5/1.7 c )
Exp. Model 2 Model 4
11a/Co ‡ 2 15 60 25 13.5 62.4 24.1 13.5 62.4 24.1
11b/Co ‡ 2 38 54 8 36.6 56.2 7.2 36.6 56.2 7.2
11c/Co ‡ 2 100 100 100
11d/Co ‡ 2 100 100 100
1.6/2.4 c ) 1.6/2.4 c )
Exp. Model 2 Model 4
11a/Ni ‡ 2 < 10 b ) 80 < 10 b ) 7.2 91.0 1.8 7.2 88.8 4.0
11b/Ni ‡ 2 < 10 b ) 80 < 10 b ) 10.1 89.30.6 10.388.31.4
11c/Ni ‡ 2 90 10 91.38.1 0.6 87.6 11.1 1.3
11d/Ni ‡ 2 90 10 91.38.1 0.6 87.6 11.1 1.3
4.0/11 c ) 3.7/8.9 c )
Exp. Model 1 Model 3
11a/FeCo ‡ 12 70 18 14.5 64.321.2 12.0 71.316.7
11b/FeCo ‡ 59 38 2 54.5 44.9 0.6 60.5 39.1 0.4
11c/FeCo ‡ 85 15 90.8 8.7 0.5 84.8 13.4 1.8
11d/FeCo ‡ 100 100 100
4.1/6.8 c ) 1.2/1.8 c )
Exp. Model 2 Model 4
11a/FeNi ‡ 387 10 7.1 85.5 7.4 7.2 83.8 9.0
11b/FeNi ‡ 20 737 b ) 19.6 78.2 2.319.9 77.4 2.7
11c/FeNi ‡ 100 100 100
11d/FeNi ‡ 100 100 100
3.1/5.2 c ) 2.8/4.4 c )
Exp. Model 2 Model 4
11a/CoNi ‡ 5 b ) 90 5 b ) 5.9 90.1 4.0 5.9 89.7 4.4
11b/CoNi ‡ 16 82 2 16.1 82.7 1.2 16.2 81.5 1.3
11c/CoNi ‡ 100 100 100
11d/CoNi ‡ 100 100 100
0.6/1.0 c ) 0.5/0.9 c )
a b ) Intensities of the products are normalized to 100%. ) Lower limits derived from analysis of the noise level.
c ) Mean deviation/maximum deviation.
H 2 ˆ f 1,1 p(H 2[d])‡ f 1,2 p(H 2[dg])‡ f scr p scr(H 2) (24)
p… HD‰ dŠ†‡f1;2p…
HD‰ dgŠ†‡fscr
KIE
pscr… HD†
(25)