Insitute of Chemical Kinetics and Combustion SB RAS, Novosibirsk, Russia.
Photochem Photobiol Sci. 2013 Sep;12(9):1666-79. doi: 10.1039/c3pp50109d.
Transient absorption and time resolved luminescence spectroscopy were used to study photophysical processes in the macrocycle-appended 1,8-naphthalimide compound H3L, and its Eu(III) and Gd(III) complexes Eu·L and Gd·L, in particular the naphthalimide-Eu(III) energy-transfer process. In all cases aggregation of the naphthalimide chromophores results in a low-energy emission feature in the 470-500 nm region in addition to the naphthalimide fluorescence; this lower-energy emission has a lifetime longer by an order of magnitude than the monomer naphthalimide fluorescence. Transient absorption spectroscopy was used to measure the decay of the naphthalimide triplet excited state, which occurs in the range 30-50 μs. In Eu·L, partial energy-transfer from the naphthalimide chromophore results in sensitized Eu(III)-based emission in addition to the naphthalimide-based fluorescence features. Time-resolved measurements on the sensitized Eu(III)-based emission reveal both fast (10(9) s(-1)) and slow (10(4) s(-1)) energy-transfer processes from the naphthalimide energy-donor, which we ascribe to energy-transfer occurring from the singlet and triplet excited state of naphthalimide respectively. This is an unusual case of observation of sensitization of Eu(III)-based emission from the singlet state of an aromatic chromophore.
瞬态吸收和时间分辨荧光光谱被用于研究大环附接的 1,8-萘二甲酰亚胺化合物 H3L 及其 Eu(III)和 Gd(III)配合物 Eu·L 和 Gd·L 的光物理过程，特别是萘二甲酰亚胺-Eu(III)能量转移过程。在所有情况下，萘二甲酰亚胺发色团的聚集导致除了萘二甲酰亚胺荧光之外，在 470-500nm 区域出现低能量发射特征；这种低能量发射的寿命比单体萘二甲酰亚胺荧光长一个数量级。瞬态吸收光谱用于测量萘二甲酰亚胺三重态激发态的衰减，其发生在 30-50μs 的范围内。在 Eu·L 中，部分能量从萘二甲酰亚胺发色团转移，导致除了萘二甲酰亚胺基荧光特征之外，还产生敏化的 Eu(III)基发射。对敏化的 Eu(III)基发射的时间分辨测量揭示了从萘二甲酰亚胺给体的快速（10(9) s(-1))和慢速（10(4) s(-1))能量转移过程，我们将其归因于分别来自萘二甲酰亚胺的单重态和三重态激发态的能量转移。这是观察从芳香族发色团的单重态敏化 Eu(III)基发射的不寻常情况。
