Multiphoton reduction of lanthanide ions and isotope enrichment by a high intensity laser

Eu^&lt；3+&gt；→Eu^&lt；2+&gt；还原Eu^-lt；3+&gt；在强激光脉冲作用下，甲醇中的Eu~(3+)离子被还原为相应的2+离子。800 nm的激发波长与它们的Eu^&lt；3+&gt；电子跃迁是非共振的。值得注意的是，当反应发生时，产生了飞秒白光激光。其机理可以用溶剂化电子的形成和还原来解释。聚焦束中的电子在溶液中的抛射伴随着白光激光。Sm^&lt；3+&gt；→Sm^&lt；2+&gt；还原发现，在强飞秒激光脉冲照射下，甲醇中的Sm~(3+)离子被还原为相应的2~+离子。在中心波长为403 nm的脉冲和800 nm的持续时间为43fs的脉冲上都观察到了减少。当激光波长调到与^6P；3/2；←^6H；5/2；…对应的403 nm处的4f-4f吸收时N越大，多光子吸收引起的还原可能是由于达到深电荷转移态所致。在钛宝石激光器基波波长为800 nm的脉冲激发下，还原被认为是通过溶剂电离和Sm^&lt；3+&gt；电子俘获发生的。首次在溶液中观察到产物Sm^&lt；2+&gt；，在15C5-醚存在下，在甲醇中有一个在750 nm附近的宽谱峰，量子产率为0.050。同位素丰度研究表明，^6P&lt；3/2&gt；←^6H&lt；5/2&gt；跃迁的摩尔消光系数在^&lt；144&gt；Sm^&lt；3+&gt；和^&lt；154&gt；Sm^&lt；3+&gt；在溶液中：因此，从Sm^&lt；3+&gt；到Sm^&lt；2+&gt；多光子还原后，应实现Sm~(2+)离子间不同的同位素分布。这一确认目前正在进行中。Yb^&lt；3+&gt；→Yb^&lt；2+&gt；反应的初步结果已经通过飞秒脉冲激发成功地还原为Yb^&lt；2+&gt；在800 nm、970 nm和1930 nm三个波长，脉冲宽度约为100fs。Yb^&lt；3+&gt；在970 nm处有4f-4f跃迁，但现阶段对Yb^&lt；2+&gt；形成的共振增强作用尚不明显。较少

Eu^<3+>→Eu^<2+> ReductionEuropium 3+ ions in methanol were found to be reduced to the corresponding 2+ ions upon irradiation with intense femtosecond laser pulses. The excitation wavelength of 800 nm was nonresonant with their electronic transitions of Eu^<3+>. It is notable that femtosecond white-light laser was generated when the reactions occurred. The mechanisms can be explained in terms of solvated electron formation followed by the reduction. The electron ejection in a focused beam in solution has been known to be accompanied by white-light laser.Sm^<3+>→Sm^<2+> ReductionSamarium 3+ ions in methanol were found to be reduced to the corresponding 2+ ions upon irradiation with intense femtosecond laser pulses. The reduction was observed at both pulses with central wavelengths of 403 nm converted from an 800-fs fundamental pulse and 800 nm with a duration of 43 fs. When the laser wavelength was tuned to the 4f-4f absorption at 403 nm corresponding to the ^6P_<3/2>←^6H_<5/2> transitio … More n, the the reduction occurred by multiphoton absorption presumably due to reaching the deep charge transfer state. In the case of excitation by 800-nm pulses of the fundamental wavelength of the Ti:sapphire laser, the reduction is considered to occur via solvent ionization followed by electron capture by Sm^<3+>. The product Sm^<2+> was detected by its fluorescence, which was observed for the first time in solution and showed a broad spectrum peak around 750 nm with a quantum yield of 0.050 in methanol in the presence of 15C5-ether.Isotope EnrichmentThe molar extinction coefficient of the ^6P_<3/2>←^6H_<5/2> transition is reportedly 10% different between ^<144>Sm^<3+> and ^<154>Sm^<3+> in solution : therefore, different isotope distributions among Samarium 2+ ions should be realized after the multiphoton reduction from Sm^<3+> to Sm^<2+>. This confirmation is currently in progress.Preliminary results for Yb^<3+>→Yb^<2+> ReactionYb^<3+> has successfully reduced to Yb^<2+> by femtosecond pulse excitation with pulse duration of about 100 fs at three wavelengths of 800 nm, 970 nm, and 1930 nm. Yb^<3+> has the 4f-4f transition at 970 nm ; however, resonance enhancement for the formation of Yb^<2+> was not clear at this stage. Less