Ln2M complexes (M = Ru, Re) derived from a bismacrocyclic ligand containing a 4,4′-dimethyl-2,2′-bipyridyl bridging unit
作者:Loïc J. Charbonnière、Stephen Faulkner、Carlos Platas-Iglesias、Martín Regueiro-Figueroa、Aline Nonat、Teresa Rodríguez-Blas、Andrés de Blas、William S. Perry、Manuel Tropiano
DOI:10.1039/c2dt32660d
日期:——
Homodinuclear lanthanide complexes derived from a ligand featuring two DO3A chelating sites linked by a 4,4â²-dimethyl-2,2â²-bipyridyl spacer were prepared and characterized. The bipyridyl coordination site of 1 was used to introduce Ru(Bpy)2 and Re(CO)3Cl moieties, leading to the formation of heterometallic dâf2 complexes with general formulae [Ln2·1·Ru(Bpy)2]2+ (Ln = Nd, Eu, Tb, Yb and Lu) and [Ln2·1·Re(CO)3Cl] (Ln = Nd, Yb and Lu). The luminescence properties of the complexes were investigated by means of absorption spectroscopy and steady-state and time-resolved luminescence spectroscopy covering the visible and NIR regions. Both Ru and Re chromophores were shown to act as efficient sensitizers of the NIR emission of Yb and Nd in aqueous solutions. We also consider the unsaturated coordination spheres of the Ln cations in the Ln2·1 complexes, which form ternary complexes with bidentate anions without showing particular synergistic effects for polyanionic species.
以一个具有两个DO3A配位位点的配体为基础,通过一个4,4'-二甲基-2,2'-联吡啶间隔物制备并表征了同核双金属镧系金属络合物。1的联吡啶配位位点被用来引入Ru(Bpy)2和Re(CO)3Cl基团,从而形成具有一般式[Ln2·1·Ru(Bpy)2]2+(Ln = Nd, Eu, Tb, Yb和Lu)和[Ln2·1·Re(CO)3Cl](Ln = Nd, Yb和Lu)的异金属d–f2络合物。通过吸收光谱、稳态和时间分辨光谱技术研究了络合物的发光特性,涵盖了可见光和近红外(NIR)区域。结果表明,无论是在水溶液中,Ru和Re色团都能有效敏化Yb和Nd的NIR发射。我们还考虑了Ln2·1络合物中Ln阳离子的未饱和配位球,这些络合物与双齿阴离子形成三元络合物,而没有显示出对多阴离子物种的特定协同效应。