Photoisomerization dynamics study on cis-azobenzene derivative using ultraviolet-to-visible tunable femtosecond pulses

Femtosecond photoisomerization of azobenzene-derivative binding to DNA

“…[12,13] was used to measure transient absorbance changes OD(t) by the noncollinear femtosecond pump-probe technique. The ultrafast laser source is a 30-fs, 2.5-mJ Ti:sapphire laser-amplifier system which provides 815 nm pulses at a repetition rate of 1 kHz.…”

“…[12,13]) describing the population dynamics of the ground states 0 S T and 0 S C as well as the second excited states 2 S T and the "bottleneck" intermediate state…”

“…Then, we investigated the transient absorption behaviors of those solutions with the rate equation analysis [12,13]. We also obtain the T-to-C photoisomerization rate  T,C per 4 femtosecond pump pulse, the yielding rate of the photoproduct C-isomer by single-shot excitation, and discuss the physical origin of the difference of the  T,C for three solutions.…”

Ultrafast photoisomerization and its single-shot pump pulse efficiency of trans-azobenzene derivative: Compound for photosensitive DNA

“…While, by visible (=400~500 nm) lamp irradiation (S 1 -band excitation) C-to-T isomerization is induced, so that the formation of AzD-bound DNA duplexes is photoregulated. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 3 unknown except for our study of the C-AzD compound [3], although, for Az related compounds, extensive studies for clarification of ultrafast photoisomerization mechanisms such as rotation, inversion and concerted inversion processes have been carried out [4][5][6][7].…”

“…The femtosecond transient absorption measurement was carried out using the wavelength-tunable optical source based on Ti-sapphire laser-amplifier pulses (30 fs, 800 nm, 2.5 mJ) at a 1-kHz repetition rate [3]: after the amplified pulses were input to an Ar-filled hollow fiber for a spectral broadening by self-phase modulation, the chirped output pulses were compensated for by visible chirped mirrors. The compensated beam was split into two beams, and then those were independently frequency-doubled by two 500-m thick -barium borate (BBO) crystals.…”