. Author manuscript; available in PMC: 2014 Nov 13.

Published in final edited form as: J Am Chem Soc. 2013 Oct 31;135(45):10.1021/ja407867a. doi: 10.1021/ja407867a

Table 1.

Photophysical properties of tetrazoles and their kinetic constants in the single-photon induced cycloaddition reaction.^a

Tetrazole	λ_max^b (nm)	ε_max^c (M⁻¹ cm⁻¹)	ε₃₆₅^d (M⁻¹ cm⁻¹)	k₀^e (μM s⁻¹)	Φ_T ^f
1	322	31,000	1,700	0.27	0.33
2	316	24,000	690	0.25	0.75
3	322	40,000	1,900	0.048	0.053
4	324	41,000	4,500	0.064	0.029
5	314	32,000	1,300	0.29	0.47
6	318	32,000	2,000	0.33	0.33

Compounds were dissolved in acetonitrile/PBS (1:1) to obtain a concentration of 25 μM. For the cycloaddition reaction, 2.5 mM acrylamide (100 equiv) was used to drive the full conversion of nitrile imine to pyrazoline.

λ_max in the 300 ~ 500 nm region.

Extinction coefficient at λ_max.

Extinction coefficient at 365 nm.

Zero-order rate constant under 365 nm photoirradiation.

Quantum yield of tetrazole ring rupture under 365 nm photoirradiation.