The structural volume changes accompanying light-induced proton transfer reactions in aqueous solutions of o-nitrobenzaldehyde have been investigated using time-resolved photoacoustics. The solvation of the newly formed ions is accopanied by a contraction of the medium of about −5.2 ± 0.2 ml/mol. At a pH above 9.5, the formation of water molecules leads to an expansion of 24.5 ± 0.4 ml/mol. The apparent rate constant for the protonation of hydroxyls is k = (4.9 ± 0.4) X 1010 M− s−. This is the first direct time-resolved measurement of the extent of the structual volume changes accompanying water formation.
Reaction volume of water formation detected by time resolved photoacoustics: photoinduced proton transfer between o-nitrobenzaldehyde and hydroxyls in water / G., Bonetti; A., Vecli; Viappiani, Cristiano. - In: CHEMICAL PHYSICS LETTERS. - ISSN 0009-2614. - 268-273:(1997), pp. 268-273. [10.1016/S0009-2614(97)00291-1]
Reaction volume of water formation detected by time resolved photoacoustics: photoinduced proton transfer between o-nitrobenzaldehyde and hydroxyls in water
VIAPPIANI, Cristiano
1997-01-01
Abstract
The structural volume changes accompanying light-induced proton transfer reactions in aqueous solutions of o-nitrobenzaldehyde have been investigated using time-resolved photoacoustics. The solvation of the newly formed ions is accopanied by a contraction of the medium of about −5.2 ± 0.2 ml/mol. At a pH above 9.5, the formation of water molecules leads to an expansion of 24.5 ± 0.4 ml/mol. The apparent rate constant for the protonation of hydroxyls is k = (4.9 ± 0.4) X 1010 M− s−. This is the first direct time-resolved measurement of the extent of the structual volume changes accompanying water formation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
