. Author manuscript; available in PMC: 2011 Oct 24.

Published in final edited form as: J Am Chem Soc. 2010 Jan 20;132(2):737–747. doi: 10.1021/ja908326z

Table 1.

Photophysical Data of Pyrazoline Derivatives 1a-e in Methanol at 298K.


compd	abs λ_max (nm)	em λ_max (nm)	Stokes shift (cm⁻¹)	ΔΕ₀₀^a (eV)	ΔG_et^b (eV)	Φ _F^c			f_e^d
compd	abs λ_max (nm)	em λ_max (nm)	Stokes shift (cm⁻¹)	ΔΕ₀₀^a (eV)	ΔG_et^b (eV)	neutral ^e	acidic ^f	Cu(I) ^g	acidic ^f	Cu(I) ^g
1a	394	487	4850	2.85	−0.22	0.0072	0.53	0.15	74	21
1b	381	480	5410	2.92	−0.31	0.0033	0.54	0.095	164	29
1c	373	464	5260	3.00	−0.39	0.0024	0.60	0.048	250	20
1d	356	445	5620	3.13	−0.47	0.0010	0.55	0.020	550	20
1e	350	448	6250	3.15	−0.54	n.d.^h	0.46	0.020	n.d.^h	n.d.^h

zero-zero transition energy; estimated based on ΔE₀₀ = (E_abs(max)+E_em(max))/2.

PET free energy change calculated according to equation (1) with w_p = −0.045 eV;¹² the experimental donor and acceptor potentials are provided with the supporting information.

fluorescence quantum yield; quinine sulfate as reference.

fluorescence enhancement factor f_e = Φ_F/Φ_neutral.

methanol.

180 mM TFA in methanol.

10 μM [Cu(I)(CH₃CN)₄]PF₆ in methanol (0.1% acetonitrile).

signal/noise ratio insufficient for accurate determination.