Charbonnière Loïc J, Mameri Samir, Flot David, Waltz Fanny, Zandanel Christelle, Ziessel Raymond F
Laboratoire de Chimie Moléculaire, UMR 7509 CNRS, ECPM-ULP, 25, rue Becquerel, 67087, Strasbourg Cedex 02, France.
Dalton Trans. 2007 Jun 14(22):2245-53. doi: 10.1039/b700837f. Epub 2007 Apr 5.
The synthesis of ligand H3 based on a disymmetrically substituted terpyridine core functionalised by a carboxylic acid in the 6-position and a bis(carboxymethyl)aminomethyl function in the 6''-position is described. The coordination behaviour of this heptadentate (4N/3O) ligand with lanthanide cations (Ln=Eu, Gd and Tb) was studied in solution showing the formation of complexes with [Ln] stoichiometry. Complexes with general formula [Ln(H2O)2] were isolated from neutral water solutions containing equimolar amounts of cations and ligands, and the complexes were characterized in the solid state (elemental analysis, IR) and in solution (mass spectrometry). The photo-physical properties of the luminescent complexes of Eu and Tb were studied in water solution by means of absorption, steady state and time-resolved emission spectroscopies. Evolution of the luminescence lifetimes of the Eu and Tb complexes in H2O and D2O reveals the presence of two water molecules coordinated in the first coordination sphere of the cations. Despite this important hydration number, the overall luminescence quantum yields of the complexes remained elevated, especially in the case of Tb (Phi=22.0 and 6.5% respectively for Tb and Eu). Upon crystallisation the Gd complex formed dimeric species in which two gadolinium atoms are each heptacoordinated by one ligand, the coordination sphere being completed by a single water molecule and a bridging carboxylate function, pointing to different behaviours in the solid and liquid states.
本文描述了基于在6位被羧酸官能化且在6''位具有双（羧甲基）氨基甲基官能团的不对称取代三联吡啶核合成配体H3的方法。研究了这种七齿（4N/3O）配体与镧系阳离子（Ln = Eu、Gd和Tb）在溶液中的配位行为，结果表明形成了具有[Ln]化学计量比的配合物。从含有等摩尔量阳离子和配体的中性水溶液中分离出通式为[Ln(H2O)2]的配合物，并对这些配合物进行了固态（元素分析、红外光谱）和溶液（质谱）表征。通过吸收光谱、稳态发射光谱和时间分辨发射光谱研究了Eu和Tb发光配合物在水溶液中的光物理性质。Eu和Tb配合物在H2O和D2O中的发光寿命变化表明，阳离子的第一配位层中有两个水分子配位。尽管水化数很大，但配合物的整体发光量子产率仍然很高，尤其是Tb的情况（Tb和Eu的量子产率分别为22.0%和6.5%）。结晶时，Gd配合物形成二聚体物种，其中两个钆原子各自由一个配体七配位，配位层由一个水分子和一个桥连羧酸根官能团完成，这表明在固态和液态中行为不同。
