Characterization of the thermal and photoinduced reactions of photochromic spiropyrans in aqueous solution
Artikel i vetenskaplig tidskrift, 2013

Six water-soluble spiropyran derivatives have been characterized with respect to the thermal and photoinduced reactions over a broad pH-interval. A comprehensive kinetic model was formulated including the spiro- and the merocyanine isomers, the respective protonated forms, and the hydrolysis products. The experimental studies on the hydrolysis reaction mechanism were supplemented by calculations using quantum mechanical (QM) models employing density functional theory. The results show that (1) the substitution pattern dramatically influences the pKa-values of the protonated forms as well as the rates of the thermal isomerization reactions, (2) water is the nucleophile in the hydrolysis reaction around neutral pH, (3) the phenolate oxygen of the merocyanine form plays a key role in the hydrolysis reaction. Hence, the nonprotonated merocyanine isomer is susceptible to hydrolysis, whereas the corresponding protonated form is stable toward hydrolytic degradation.

Författare

Martin Hammarson

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Jesper Nilsson

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Shiming Li

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Tamas Beke-Somfai

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Joakim Andreasson

Chalmers, Kemi- och bioteknik, Fysikalisk kemi

Journal of Physical Chemistry B

1520-6106 (ISSN) 1520-5207 (eISSN)

Vol. 117 13561-71

Ämneskategorier

Fysikalisk kemi

DOI

10.1021/jp408781p