residual emission anisotropy

https://doi.org/10.1351/goldbook.RT07473
Photoselected molecules hindered in their rotation (e.g., in lipid bilayers or liquid crystals) do not become randomly oriented even after long time periods. Thus, the @[email protected] does not decay to zero but to a steady value, \(r_{\mathrm{\infty }}\), called residual @[email protected] In the case of a single rotational correlation time, \(\tau _{\mathrm{c}}\) or \(\theta \), the decay of @[email protected] following δ-pulse excitation is given by: \[r\left(t\right)=(r_{0}- r_{\mathrm{\infty }})\ \exp (- \frac{t}{\tau _{\mathrm{c}}})+r_{\mathrm{\infty }}\] where \(r_{0}\) is the fundamental @[email protected]
Note:
The term residual @[email protected] is to be preferred to 'limiting @[email protected]'.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 414 [Terms] [Paper]