Conclusions
The fluorescence lifetime of free DCM was a biexponential decay _1= 2.82 ns and _2= 0.24 ns. DCM bound to _-CD has a lifetime of 1.39 ns.
DCM bound to _-CD has a lifetime of 1.12 ns.
In _-CD solutions, free DCM has a RCT of 0.06 ns and bound DCM has a slower RCT of 0.515 ns .
In _-CD solutions, free DCM has a RCT of 0.15 ns and bound DCM has a slower RCT of 1.28 ns .
Debeye-Stokes equation suggests about 1 water of hydration surrounding _-CD, but not _-CD.