Skip to main content

Rotational Reorientation Dynamics of Xanthene Dyes within the Interior of Aerosol-OT Reversed Micelles

Buy Article:

$29.00 plus tax (Refund Policy)


The rotational reorientation kinetics of several xanthene dye molecules [rhodamine 6G (R6G), rhodamine B (RB), rhodamine 101 (R101), and fluorescein (FLR)] have been investigated in sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol-OT; AOT) reverse micelles formed in liquid n-heptane. We show that the water content within the micellar core and the probe structure have a significant effect on the rotational dynamics of the probe. The differential phase and polarized modulation ration data (decays of anisotropy) are always best described by a bi-exponential decay law. We interpret these results in terms of a two-step model for lateral diffusion and a wobbling-in-a-cone model. The former model described the observed bi-exponential decay by attributing the slower of the two rotational motions to lateral diffusion along the water core/headgroup interfacial region and the faster motion to a more restricted internal motion. The results show that, for the cationic probes, lateral diffusion coefficients vary by more than an order of magnitude across the water-loading range investigated. The wobbling-in-a-cone model serves to quantify the restricted internal motion of the probe in terms of a cone angle () and wobbling diffusion coefficient. The semiangle covers a wide range for the cationic probes (0 ≤  ≤ 35) depending on the specific probe structure and R ([water]/[AOT]) value. The anionic probe shows a larger semiangle at each R value relative to the cationic probes.

Keywords: Lateral diffusion model; Reverse micelles; Rotational reorientation; Wobbling-in-a-cone model; Xanthene dyes

Document Type: Research Article


Affiliations: Department of Chemistry, Natural Science and Mathematics Complex, State University of New York at Buffalo, Buffalo, New York 14260-3000

Publication date: January 1, 1995

More about this publication?

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more