| 查看: 369 | 回复: 2 | ||
andyzhu木虫 (正式写手)
|
[求助]
求助稀土配合物荧光的问题
|
| 我合成了2个稀土配合物，分别是Ce和Pr的，测它们的荧光时发现配合物不显示稀土离子的荧光，而只显示配体的荧光，这是怎么回事？应该如何解释呢？我这个现象能不能写到我的文章中去呢？相当纠结，烦请大侠们帮帮忙啊。感激不尽啊。 |
回复此楼» 猜你喜欢
反应很差，大量原料没有反应
已经有7人回复
-
面上本子正文33页，违规吗？会被低分嘛？
已经有13人回复
-
评审有感
已经有23人回复
-
提交了我也来说说感想
已经有6人回复
-
Sci. Bull. 悲剧经验
已经有7人回复
-
今年审到国自然15份，谈谈感受
已经有20人回复
-
国自然评分
已经有4人回复
-
如果工作了想读博，可以边工作边读全日制嘛？
已经有5人回复
-
如何实现卤原子转化
已经有8人回复
-
河北省自然科学基金
已经有3人回复
» 本主题相关价值贴推荐，对您同样有帮助:
- 稀土配合物荧光光谱
已经有10人回复
- 【求助】稀土配合物的纯化
已经有3人回复
- 【求助】有人做稀土配合物的吗？交流下啊！
已经有22人回复
- 【求助】想形成稀土金属 例如镧等和8-羟基喹啉或者双硫腙的配合物 但是没有找的合适条
已经有3人回复
- 【求助/交流】近红外荧光染料
已经有8人回复
- 【求助】求助稀土发光的问题
已经有4人回复
- 【求助】有有关Dy配合物的荧光问题
已经有8人回复
- 【求助】为什么我做的Eu三元配合物没有荧光呢
已经有12人回复
- 【求助】稀土有机配合物确定最佳激发波长时的监测波长是如何确定的？
已经有6人回复
【答案】应助回帖
andyzhu(金币+8): 你好，能不能把书发给我啊？ 2011-10-12 08:52:16
|
1.3.5 The Emission Spectra of Rare Earth Compounds In the 1940s, emissions from rare earth complexes were observed and research into this phenomenon has received growing and lasting attention because of their potential application in optical communications, new generation displays, and sensors. Since the dipole strength of f -f transitions are formally forbidden, typically, these extinction coefficients are of the order of 1 M−1cm−1, an alternative path has to be used which is called luminescence sensitization or antenna effect, that is when the luminescent ion is coordinated with an organic ligand or imbedded into a matrix, then the energy absorbed will be transferred from the surrounding onto the luminescent ion and subsequently the ion emits characteristic light. According to the emission properties, rare earth complexes can be divided into four groups as follows: 1. Sm3+(4f 5), Eu3+(4f 6), Tb3+(4f 8) and Dy3+(4f 9); 2. Pr3+(4f 2), Nd3+(4f 3), Ho3+(4f 10), Er3+(4f 11), Tm3+(4f 12) andYb3+(4f 13); 3. Sm2+(4f 6), Eu2+(4f 7), Yb2+(4f 14) and Ce3+(4f 1); 4. Sc3+(4f 0), Y3+(4f 0), La3+(4f 0), Gd3+(4f 7) and Lu3+(4f 14). For the first group, emissions originate because of the transition of 4f electrons from the lowest excited states to the ground states and the emissions are in the visible region. The probabilities of these transitions are relatively high and strong emissions may be observed. The lifetimes of these emissions are in the microsecond or milliseconds scale. For the second group, the energy levels of these ions are very close to one another. Thus, the emissions are often in the infrared region and their intensities are weaker than those of the first group by several orders of magnitude.All the ions in the third group exist in lower oxidation states and their emissions originate from d–f transitions and not f–f transitions, which would show broader emission bands. Obviously, the ions in the last group all have so-called stable electronic configurations, that is, their 4f orbitals are either “empty,’’ “half-filled’’ or “all-filled.’’ Therefore, no f–f transitions occur except in gadolinium complexes, which emit in the ultraviolet region. However, these complexes do sometimes emit when suitable ligands are coordinated to the central ions. In these cases, the emissions are caused by ligand emission complexes 摘自 RARE EARTH COORDINATION CHEMISTRY |
2楼2011-10-12 08:35:33
tingting888
银虫 (正式写手)
- 应助: 3 (幼儿园)
- 金币: 315.6
- 散金: 246
- 红花: 7
- 帖子: 604
- 在线: 152.4小时
- 虫号: 486914
- 注册: 2007-12-28
- 专业: 配位化学
3楼2011-12-22 19:02:58
5