MEASUREMENTS OF THE SOLUTE DEPENDENCE OF SOLVATION DYNAMICS IN 1-PROPANOL - THE ROLE OF SPECIFIC HYDROGEN-BONDING INTERACTIONS

Citation
Cf. Chapman et al., MEASUREMENTS OF THE SOLUTE DEPENDENCE OF SOLVATION DYNAMICS IN 1-PROPANOL - THE ROLE OF SPECIFIC HYDROGEN-BONDING INTERACTIONS, Journal of physical chemistry, 99(13), 1995, pp. 4811-4819
Citations number
39
Categorie Soggetti
Chemistry Physical
ISSN journal
00223654
Volume
99
Issue
13
Year of publication
1995
Pages
4811 - 4819
Database
ISI
SICI code
0022-3654(1995)99:13<4811:MOTSDO>2.0.ZU;2-E
Abstract
Time-resolved Stokes shift measurements (similar to 20 ps effective re solution) are used to measure the solvation times of 16 different prob e solutes in a single solvent, 1-propanol (253 K). The solutes were ch osen so as to provide a wide range of chemical structures and physical properties consistent with the requirements of strong fluorescence an d high solvent sensitivity. Rather than exhibiting a continuous range of solvation times, the dynamics observed with these solutes indicated a division into two distinct classes. The majority (11) of the solute s were observed to fall into a ''normal'' category. The solvation time s of these solutes span a relatively narrow range, 0.14-0.22 ns, times consistent with expectations based on nonspecific theories of solvati on dynamics. The remaining five solutes, all simple aromatic amines, f orm a distinct group whose solvation dynamics is at least 2-fold faste r than those of the ''normal'' solutes. The difference between these t wo classes of solutes appears to reflect differences in the nature of their hydrogen-bonding interactions with the solvent.