2,2,6,6-Tetramethylpiperidine Singlet oxygen

Belford, R.E.; Seely, G.R.; Gust, D.; Moore, T.A.; Moore, A.; Cherepy, N.J.; Ekbundit, S.; Lewis, J.E.; Lin, S.H.
J. Photochem. Photobiol., A 70, 125-133 (1993)

Reaction: 2,2,6,6-Tetramethylpiperidine + ¹O₂^* ® products and/or physical quenching
Solvent: CH₂Cl₂

k = 3.9 × 10⁵(L mol^-1 s^-1)

Experimental method: Flash photolysis
Analytical method: infrared luminescence
Data type: Absolute value measured directly
Excitation wavelength: 514 nm

Photosensitizer = 5,10,15,20-Tetraphenylporphine.

Zang, L.-Y.; Zhang, Z.; Misra, H.
Photochem. Photobiol. 52, 677-683 (1990)

Reaction: 2,2,6,6-Tetramethylpiperidine + ¹O₂^* ® TMPN
Solvent: C₆H₆

k = 5.3 × 10⁵(L mol^-1 s^-1), b = 6.1 × 10^-2(mol L^-1)

Experimental method: Photolysis
Analytical method: electron spin resonance
Data type: Derived from steady state measurements

Photosensitizer = Hypocrellin A; used solvent k_d = 3.2 × 10⁴ s^-1. Obs. formn. of 2,2,6,6-tetramethylpiperidine N-oxyl. [Sensitizer] = 8 × 10^-5 (mol L^-1).

Yang, X.-Z.; Chen, Y.; Dickinson, L.C.; Chien, J.C.W.
Polym. Degrad. Stab. 20, 1-35 (1988)

Reaction: 2,2,6,6-Tetramethylpiperidine + ¹O₂^* ® products and/or physical quenching
Reference Reaction: Rub + ¹O₂^* ®
Solvent: Methylene chloride

k = 4 × 10⁵(L mol^-1 s^-1)

Experimental method: Photolysis
Analytical method: vis-UV emission
Data type: Derived from steady state measurements using indicator
Excitation wavelength: 520 nm

Photosensitizer = Indicator = Rubrene, k for indicator = 7 × 10⁷ L/(mol·s); used solvent k_d = 7.3 × 10³ s^-1. [Sensitizer] = 1.6 × 10^-6 (mol L^-1). [O₂] = air.

Ballardini, R.; Beggiato, G.; Bortolus, P.; Faucitano, A.; Buttafava, A.; Gratani, F.
Polym. Degrad. Stab. 7, 41-53 (1984)

Reaction: 2,2,6,6-Tetramethylpiperidine + ¹O₂^* ® products and/or physical quenching
Solvent: Benzene, 80%, Methanol, 20%

k = 4.0 × 10⁶(L mol^-1 s^-1)

Experimental method: Flash photolysis
Analytical method: vis-UV absorption
Data type: Absolute value measured directly using indicator
Excitation wavelength: 694 nm

Photosensitizer = Methylene Blue; Indicator = 1,3-Diphenylisobenzofuran.

Rabek, J.F.; Ranby, B.; Arct, J.; Liu, R.
J. Photochem. 25, 519-536 (1984)

Reaction: 2,2,6,6-Tetramethylpiperidine + ¹O₂^* ® products and/or physical quenching
Solvent: Methylene chloride

k = 3.8 × 10⁵(L mol^-1 s^-1)

Experimental method: Photolysis
Analytical method: vis-UV absorption
Data type: Derived from steady state measurements using indicator

Photosensitizer = Indicator = Rubrene; k for indicator = 7.3 × 10⁷ L/(mol·s); k_d not given.

Reszka, K.; Chignell, C.F.
Photochem. Photobiol. 38, 281-291 (1983)

Reaction: 2,2,6,6-Tetramethylpiperidine + ¹O₂^* ® products and/or physical quenching
Solvent: EtOH

k = 1.6 × 10⁵(L mol^-1 s^-1)

Experimental method: Photolysis
Analytical method: electron spin resonance
Data type: Derived from steady state measurements
Excitation wavelength: 309 nm

Photosensitizer = Benoxaprofen; used solvent k_d = 8.3 × 10⁴ s^-1; Obs. formn. of 2,2,6,6-tetramethylpiperidine N-oxyl.