The temperature dependent luminescent decay kinetics of an emissive copper complex in the single crystalline phase using time-gated luminescence microscopy

The temperature dependence of the luminescent lifetime of a single crystal of Cu(I) phenanthroline, [Cu(dmp)(PPh3)2]BF4 (dmp=2,9-dimethyl-1,10-phenanthroline and PPh3=triphenylphosphine), was measured using a fluorescence lifetime imaging microscope utilizing time-gated CCD detection. At all temperatures between 100 K and 292 K, the single crystals exhibited biexponential luminescent decay as well as non-linear Arrhenius luminescent decay kinetics. Variable temperature single-crystal XRD measurements revealed that the observed behavior is likely not the result of a crystallographic phase transition.