Synthesis and luminescence properties of Cr(III) complexes with cyclam-type ligands having pendant chromophores, trans-[Cr(L)Cl(2)]Cl.
Synthesis and luminescence properties of Cr(III) complexes with cyclam-type ligands having pendant chromophores, trans-[Cr(L)Cl(2)]Cl.
复制标题
Cr(III) 配合物与具有悬垂发色团反式-[Cr(L)Cl(2)]Cl 的 cyclam 型配体的合成和发光特性。
作者：
F. Derosa;X. Bu;K. Pohaku;P. Ford
报道了新型环类配体5,7-二甲基-6-R-1,4,8,11-四氮杂环十四烷(L)的合成和光谱性质，其中R是一个悬垂的发色团，如蒽衍生物。根据镍（II）模板法制备了这些配体，并描述了几种镍（II）中间体的x射线晶体结构。自由碱配体L与CrCl(3)x3THF反应，容易形成反式[Cr(L)Cl(2)]Cl配合物，并描述了这些配合物的结构和光谱表征。对反式-[Cr(L)Cl(2)]Cl溶液在77 K下的光物理性质的研究表明，发射光谱主要是由铬（III）中心的配体场偶联体发出的磷光。这也适用于Cr（III）配合物反式-[Cr(mac)Cl(2)]Cl，其中mac是蒽衍生物5,7-二甲基-6-蒽环环酮。激发到蒽的π - π(*)态导致该发色团的荧光明显猝灭，而金属中心重态的磷光被敏化。
The synthesis and spectroscopic properties of new cyclam-type ligands 5,7-dimethyl-6-R-1,4,8,11-tetraazacyclotetradecane (L), where R is a pendant chromophore such as an anthracene derivative, are reported. These ligands were prepared according to a nickel(II) template procedure, and the X-ray crystal structures of several Ni(II) intermediates are described. Reaction of the free base ligands L with CrCl(3)x3THF resulted in facile formation of trans-[Cr(L)Cl(2)]Cl complexes, and the structures and spectroscopic characterizations of these complexes are also described. Examination of the photophysical properties of trans-[Cr(L)Cl(2)]Cl solutions at 77 K demonstrated the emission spectra to be dominated by phosphorescence from the ligand field doublet of the chromium(III) center. This also applies to the Cr(III) complex trans-[Cr(mac)Cl(2)]Cl, where mac is the anthracene derivative 5,7-dimethyl-6-anthracenylcyclam. Excitation into the pi-pi(*) states of the anthracene leads to marked quenching of the fluorescence from this chromophore and sensitized phosphorescence from the metal-centered doublet state.