Photophysical and structural impact of phosphorylated anions associated to lanthanide complexes in water
Photophysical and structural impact of phosphorylated anions associated to lanthanide complexes in water
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DOI：
10.1021/ic051033o
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发表时间：
2005-10-03
影响因子：
4.6
通讯作者：
Ziessel, RF
中科院分区：
文献类型：
--
作者：
Charbonnière, LJ;Schurhammer, R;Ziessel, RF
合成了一种新的配体L-C，双-[（6 ′-羧基-2，2 ′-联吡啶-6-基）]苯基氧化膦，其中6-羧基-2，2 ′-联吡啶三齿臂直接连接在苯基氧化膦片段上。从含有等摩尔量Lc和水合LnCl（3）盐的溶液中分离出相应的[Ln中心点Lc]Cl中心点xH（2）O配合物（Ln = Eu，x = 4和Tb，x = 3），并通过元素分析、质谱和红外光谱进行表征。通过滴定实验、紫外-可见光谱、荧光光谱和激发态寿命测量研究了Eu配合物与各种阴离子（AMP（2-）、ADP（3-）、ATP、（4-）HPO_（42-）和NO_（3-））的相互作用。在TRIS/HCl缓冲液（0.01 M，pH = 7.0）中，条件逐步缔合常数的测定结果表明，该配合物与ADP（3-）、ATP（4-）和磷酸根阴离子有较强的相互作用。这些值高于对配体La，双[（6 '-羧基-2，2'-联吡啶-6-甲基）]-正丁胺测定的值（Δ log K近似于1-2）。用量子力学方法研究了配合物[Ln-L-C]（+）和[Ln-L-B]（+）与硝酸根、磷酸一氢根、磷酸甲酯（MeP 2-）、磷酸二甲酯（MeDP 3-）和三磷酸甲酯（MeTp（4-））阴离子的相互作用.的结果，结合数据的顺序竞争性结合的阴离子的Eu配合物在水中的生物物理的影响，表明LB是太灵活，以确保一个良好的协调口袋，而配体LC的分子结构稳定的镧系元素配合物的形成和其与ATP的加合物。
A new ligand, L-C, bis-[(6'-carboxy-2,2'-bipyridine-6-yl)]phenylphosphine oxide, in which the tridentate 6-carboxy2,2'-bipyridyl arms are directly linked to a phenylphosphine oxide fragment, has been synthesized. The corresponding [Ln center dot Lc]Cl center dot xH(2)O complexes (Ln = Eu, x = 4, and Tb, x = 3) were isolated from solutions containing equimolar amounts of Lc and hydrated LnCl(3) salts and characterized by elemental analysis, mass spectrometry, and infrared spectroscopy. The interactions of the Eu complex with various anions (AMP(2-), ADP(3-), ATP,(4-) HPO42-, and NO3-) were studied by titration experiments, using UV-vis, luminescence spectroscopy, and excited-state lifetime measurements. The results are in keeping with strong interactions with the ADP(3-), ATP(4-), and phosphate anions in TRIS/HCI buffer (0.01 M, pH = 7.0), as revealed by the determination of the conditional stepwise association constants. These values are higher than the one determined for ligand La, bis[(6'-carboxy-2,2'-bipyridine-6-methylyl)]-n-butylamine (Delta log K approximate to 1-2). The interaction of complexes [Ln center dot L-B](+) and [Ln-L-C ](+) with nitrate, monohydrogenophosphate, methyl phosphate (MeP2-), methyldiphosphate (MeDP3-), and methyltriphosphate (MeTp(4-)) anions was investigated by means of quantum mechanical (QM) calculations. The results, combined with data on the photophysical impact of the sequential competitive binding of anions to the Eu complexes in water, suggest that LB is too flexible to ensure a good coordination pocket, while the molecular structure of ligand Lc stabilizes both the formation of the lanthanide complexes and its adducts with ATP.