Effect of thienyl groups on the photoisomerization and rotamerism of symmetric and asymmetric diaryl-ethenes and diaryl-butadienes

被引：23

作者：

Giampiero Bartocci ^{[17
]}

Guido Galiazzo ^{[27
]}

Gabriella Ginocchietti ^{[17
]}

Ugo Mazzucato ^{[17
]}

Anna Spalletti ^{[17
]}

机构：

[1] Dipartimento di Chimica, Università di Perugia, Perugia

[2] Dipartimento di Scienze Chimiche, Università di Padova, Padova

来源：

Photochemical & Photobiological Sciences | 2004年 / 3卷 / 9期

关键词：

D O I：

10.1039/b408241a

中图分类号：

学科分类号：

摘要：

Five symmetric (bis-substituted) and asymmetric (mono-substituted) analogues of E-stilbene and EE-1,4-diphenylbutadiene, where one or both the side aryls are 2′-thienyl or 3′-thienyl groups, have been studied by stationary and pulsed fluorimetric techniques, laser flash photolysis, conventional photochemical methods and theoretical calculations. The results obtained for these compounds and the comparison with those previously reported for three other compounds of the same series, allowed the effects of the position of the heteroatom and of the extension of the olefin chain on the excited state relaxation properties to be understood. The presence of one or two thienyl groups and their positional isomerism affect the spectral behaviour, the relaxation properties (radiative/reactive competition), the photoisomerization mechanism (singlet/triplet) and the ground state rotamerism. For the dienes containing the 3′-thienyl substituent(s), two rotamers were evidenced whose radiative and photochemical properties were obtained by selective excitation. © 2004 The Royal Society of Chemistry and Owner Societies.

引用

页码：870 / 877

页数：7

共 32 条

[1]

Gajdek P., Becker R.S., Elisei F., Mazzucato U., Spalletti A., Excited state behaviour of some trans-stilbene analogues bearing thiophene rings, J. Photochem. Photobiol., A: Chem., 100, pp. 57-64, (1996)

[2]

Spalletti A., Bartocci G., Elisei F., Masetti F., Mazzucato U., Effect of pyridyl and thienyl groups on the excited state properties of stilbene-like molecules, Proc. Indian Acad. Sci. (Chem. Sci.), 110, pp. 297-310, (1998)

[3]

Bartocci G., Spalletti A., Becker R.S., Elisei F., Floridi S., Mazzucato U., Excited-state behaviour of some all-trans-α,ω-dithienylpolyenes, J. Am. Chem. Soc., 121, pp. 1065-1075, (1999)

[4]

Bartocci G., Galiazzo G., Gennari G., Marri E., Mazzucato U., Spalletti A., Effect of the nature of aryl and heteroaryl groups on the excited state properties of asymmetric 1,4-diarylbutadienes, Chem. Phys., 272, pp. 213-225, (2001)

[5]

Millefiori S., Scarlata G., Millefiori A., Carbone D., Ultraviolet photoelectron and absorption spectra of aryl and thienyl-ethylenes, Z. Phys. Chem. N. F., 128, pp. 63-72, (1981)

[6]

Costanzo L.L., Pistara S., Condorelli G., Scarlata G., Direct and sensitized cis–trans photoisomerization of 2-styrylthiophene, J. Photochem., 7, pp. 297-304, (1977)

[7]

Costanzo L.L., Pistara S., Chiacchio U., Effect of azulene on the direct and benzil-sensitized photoisomerization of 2-styrylthiophene, J. Photochem., 26, pp. 79-84, (1984)

[8]

Zimmerman A.A., Orlando C.M., Gianni M.H., Weiss K., Concentration effects in photochemical cis–trans isomerization. A study of difurylethylene and dithienylethylene, J. Org. Chem., 34, pp. 73-77, (1969)

[9]

Song K., Peng M.-L., Xu M., Wu L.-Z., Zhang L.-P., Tung C.-H., Synthesis of carbo- and aza-bicyclo[4.3.0] and [4.4.0] compounds by Ti(II)-mediated cyclization of 2,7- or 2,8-enynyl-1-ol derivatives, Tetrahedron Lett., 43, pp. 6633-6636, (2002)

[10]

Hamed M.M., Abu-Eittah R.H., Mohamed A.A., Spectroscopic studies on styryl-, thienylethenyl- and furylethenyl-pyridines: Molecular orbital treatment and effect of positional isomerism, J. Chem. Soc., Faraday Trans., 88, pp. 955-962, (1992)

← 1 2 3 4 →