Table 1.

Spectroscopic and photophysical data of W at 25 µM in the absence and presence of Me-β-CD (1.0 mM). The DAS maximum for each lifetime is given in bracket.

Drug Forms	λabs/nm	ϵ/M−1·cm–1	λex/nm	λem/nm	τ1/ns (λem/nm)	τ2/ns (λem/nm)
Free (pH 3)	305	10 680	320	358	<0.1
	282	12 820	280	358	<0.1
Free (pH 9)	309	13 532	320	390	<0.1
Complex (pH 3)	306	10 102	320 a	358	<0.1 (358)	2.0 ± 0.4 b (375)
Complex (pH 9)	309	13 580	320	390	<0.1 (390)	1.22 ± 0.02 b (390)

^a With excitation at 280 nm, no change in excited-state lifetime was observed. ^b Values are presented as mean ± standard deviation. The estimated experimental error was 20% and 1.6% for the complex lifetimes at pH 3 and 9, respectively.