Gerz Isabelle, Jannuzzi Sergio Augusto Venturinelli, Hylland Knut T, Negri Chiara, Wragg David S, Øien-Ødegaard Sigurd, Tilset Mats, Olsbye Unni, DeBeer Serena, Amedjkouh Mohamed
Department of Chemistry University of Oslo P. O. Box 1033 Blindern 0315 Oslo Norway.
Centre for Materials Science and Nanotechnology University of Oslo P.O. Box 1126 Blindern 0316 Oslo Norway.
Eur J Inorg Chem. 2021 Dec 14;2021(46):4762-4775. doi: 10.1002/ejic.202100722. Epub 2021 Oct 29.
A series of Cu(I) complexes of bidentate or tetradentate Schiff base ligands bearing either 1--imidazole or pyridine moieties were synthesized. The complexes were studied by a combination of NMR and X-ray spectroscopic techniques. The differences between the imidazole- and pyridine-based ligands were examined by H, C and N NMR spectroscopy. The magnitude of the N coordination shifts was found to be strongly affected by the nature of the heterocycle in the complexes. These trends showed good correlation with the obtained Cu-N bond lengths from single-crystal X-ray diffraction measurements. Variable-temperature NMR experiments, in combination with diffusion ordered spectroscopy (DOSY) revealed that one of the complexes underwent a temperature-dependent interconversion between a monomer, a dimer and a higher aggregate. The complexes bearing tetradentate imidazole ligands were further studied using Cu K-edge XAS and VtC XES, where DFT-assisted assignment of spectral features suggested that these complexes may form polynuclear oligomers in solid state. Additionally, the Cu(II) analogue of one of the complexes was incorporated into a metal-organic framework (MOF) as a way to obtain discrete, mononuclear complexes in the solid state.
合成了一系列带有1-咪唑或吡啶基团的双齿或四齿席夫碱配体的Cu(I)配合物。通过核磁共振(NMR)和X射线光谱技术相结合的方法对这些配合物进行了研究。通过氢、碳和氮核磁共振光谱研究了基于咪唑和吡啶的配体之间的差异。发现配合物中杂环的性质对氮配位位移的大小有很大影响。这些趋势与单晶X射线衍射测量得到的Cu-N键长有很好的相关性。变温核磁共振实验与扩散有序光谱(DOSY)相结合表明,其中一种配合物在单体、二聚体和更高聚集体之间发生了温度依赖性的相互转化。使用Cu K边X射线吸收光谱(XAS)和VtC X射线发射光谱(XES)对带有四齿咪唑配体的配合物进行了进一步研究,其中光谱特征的密度泛函理论(DFT)辅助归属表明这些配合物在固态中可能形成多核低聚物。此外,其中一种配合物的Cu(II)类似物被纳入金属有机框架(MOF)中,作为在固态中获得离散单核配合物的一种方法。