Photochemistry of Lanthanide Ions-Multiphoton Chemistry via 4f Electronic Excited States-

用双色双光子激发的激光照射乙醇溶液，发现Yb ~（3+）离子被还原为相应的Yb ~（2+）离子，用脉宽为4 ns的红外（975 nm）脉冲泵浦，Yb ~（3+）离子的基态被还原为4f激发态， 2F 5/2- 2F 7/2跃迁，第二个光子（355 nm）产生Cl 3d到Yb 4f的电荷转移（CT）态;然后发生还原。激光能量对UV和IR的每种颜色以及对IR波长的依赖性证明了上述机制。用纳秒激光光解法测量了双光子化学中从4f激发态（2F_（5/2））到CT态的中间吸收光谱，中间吸收光谱出现在波长小于400 nm的范围内，单光子紫外激发和双光子激发中第二光子的反应产额为0.1 ~ 0.2。 这些化学物质有望用于核废料处理。

Ytterbium 3+ ions in alcohol were found to be reduced to the corresponding 2+ ions upon laser irradiation with a stepwise two-color two-photon excitation.The infrared (975-nm) pulse with a duration of 4 ns pumps the ground state to the 4f excited state with the transition of 2F5/2-2F7/2, and the second photon (355-nm) generates the charge transfer(CT)state of Cl3d to Yb4f;the reduction then occurs. Laser energy dependencies on each color of UV and IR, and on IR wavelengths demonstrate the above mechanism. The intermediate absorption spectrum in the two-photon chemistry was measured from the 4f excited state (2F5/2) to the CT state by nanosecond laser photolysis.The intermediate spectrum appears in the wavelengths shorter than 400 nm.The reaction yields for single- photon UV excitation and the second photon in the two-photon excitation were 0.1-0.2. These chemistries are hopefully useful for nclear waste treatment.