Frequency-domain fluorescence intensity decays of the intramolecular excimer forming (DipyPE) in a fully hydrated dioleoyl-phosphatidylethanolamine (DOPE) suspension have been measured at the monomer (395 nm) and excimer (475 nm) emissions and at different temperatures (0–30°C). A classical Birks (two-state) and a new three-state kinetics models were used to analyze the frequency-domain data. The three-state model allowed us to resolve various intramolecular dynamics parameters of DipyPE in the host DOPE suspension. Those parameters are the excimer association (Kdm) and dissociation (Kmd) rate constants, effective concentration (C), and lateral diffusion rate (f) of the pyrene moieties in the DipyPE. In contrast, only CKdm and Kmd were determined based on the two-state model. We observed that Kdm declined while C increased abruptly at ∼12°C, the known thermotropic lamellar liquid crystalline-to-inverted hexagonal (Lα-HII) phase transition temperature of DOPE. No abrupt changes in Kmd and f were observed at all temperatures. We concluded that the rotation of the lipid acyl chains is hindered and the free volume available for the lipid terminal methyl ends is reduced as the lipid membrane enters the highly curved HII phase from the planar Lα phase.