Jm. Stadlbauer et al., KINETIC ISOTOPE EFFECTS FROM REACTIONS OF MUONIUM ATOMS IN WATER WITHVARIOUS KETONES, AND ACETALDEHYDE - CONTRASTS WITH HYDROGEN-ATOMS, Canadian journal of chemistry, 75(1), 1997, pp. 74-76
This paper presents data showing that in dilute aqueous solutions of b
utanone, 3-pentanone, cyclohexanone, di-tert-butyl ketone, and acetald
ehyde the addition reaction of muonium atoms occurs with a rate consta
nt close to 1 x 10(8) M-1 s(-1). The same value was obtained previousl
y for acetone. Thus the reaction rate is virtually independent of the
group attached to the C=O, be it a methyl, methylene, tert-butyl, or e
ven a hydrogen atom. This is in sharp contrast to the reactivity of or
dinary H-1 atoms, whose rate constants are much slower and dependent o
n adjacent groups. In fact muonium and H-1 react by different mechanis
ms, to form different products, so their rate ratio represents a compl
ex kinetic isotope effect.