Measurements of pK(a) of organic molecules using third-order nonlinear optics

Citation
Re. De Araujo et al., Measurements of pK(a) of organic molecules using third-order nonlinear optics, CHEM P LETT, 330(3-4), 2000, pp. 347-353
Citations number
20
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
CHEMICAL PHYSICS LETTERS
ISSN journal
00092614 → ACNP
Volume
330
Issue
3-4
Year of publication
2000
Pages
347 - 353
Database
ISI
SICI code
0009-2614(20001110)330:3-4<347:MOPOOM>2.0.ZU;2-Q
Abstract
We report the use of the Z-scan method, which is a nonlinear optical techni que, as a general method to determine a chemical parameter, the pK(a), whic h characterizes the equilibrium constant in acid-base reactions. The measur ements were performed with picosecond pulses at 532 nm in aqueous solution of methyl orange, C14H14N3O3S- The experimental results agree well with a p henomenological description of the molecule nonlinearity as well as with th e results predicted using the Henderson-Hasselbalch equation. (C) 2000 Else vier Science B.V. All rights reserved.