A photophysical study of purines and theophylline by using laser-induced optoacoustic spectroscopy.
The photophysics of purinic compounds (purine, 6-methylpurine, 6-aminopurine [adenine], 6-chloropurine, 6-methoxypurine) and theophylline in acetonitrile solution were studied by pulsed laser-induced optoacoustic spectroscopy (LIOAS) exciting at 266 nm. The effect of O2, Xe and MnCl2 on the photophysical behavior of these compounds was studied; as well, the formation quantum yield of purine and 6-methylpurine triplet states were determined, with phi T = 0.88 +/- 0.03 for both compounds. Multiphotonic and depletion processes were observed at high laser fluences. In order to explain this behavior, theoretical UV-visible absorption electronic spectra from both the S0 and S1 state have been calculated for purines and theophylline by using the semiempirical PM3 and ZINDO/S methods.
Murgida
D H
DH
Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Agrentina. murgida@quimor.qo.fcen.uba.ar
Bilmes
G M
GM
Erra-Balsells
R
R
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D007834:Lasers; D010777:Photochemistry; D011687:Purines / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods; D013806:Theophylline / Q000737:chemistry*
D011687:Purines; D013806:Theophylline