Zn(protoporphyrin) excited state quenched by Zn(protoporphyrin)

Zn(protoporphyrin) quenched by Zn(protoporphyrin)
Solvent : EtOH/H₂O (1.2/1), 0.001 mol/L Pbuf, pH 8

k_q = 4 x 10⁷(L mol^–1 s^–1)

Experimental methods: laser flash, luminescence,
Lifetime in the absence of quencher, air free = ~3. x 10³ micro sec.
Comments: tau₀ extrap'd to [S] = 0