Scandium complexes bearing bis(oxazolinylphenyl)amide ligands: an analysis of their reactivity, solution-state structures and photophysical properties

The coordination chemistry of scandium supported by bis(oxazolinylphenyl)amide (R-BOPA) ligands is reported. The R-BOPA ligand is too sterically demanding to afford bis(amide) complexes [Sc(R-BOPA){N(SiMe3)2}2], but reaction of the protio-ligand with [Sc{N(SiMe3)2}2Cl] (1) afforded the mixed amido-chloride complexes [Sc(R-BOPA){N(SiMe3)2}Cl] (2). The selective reaction of the amido and chloride co-ligands in 2 has been investigated; whilst the chloride ligand can be removed cleanly by metathesis, protonation of the N(SiMe3)2 ligand results in competitive protonation of the R-BOPA ligand. The complexes [Sc(R-BOPA)(CH2SiMe2Ph)2] (5) have been synthesised. Each R-BOPA-containing complex exists in two isomeric forms. The equilibrium has been investigated both experimentally and computationally, and the data suggest that a concerted rotation of the phenyl rings interconverts the two diastereomeric isomers. All of the R-BOPA complexes were found to be luminescent; an analysis of the photophysics, aided by TD-DFT calculations, suggests ligand-centred luminescence with distinct emission lifetimes for each isomer. The dataset contains all experimental spectroscopic data (e.g. NMR data), crystallographic data (raw hl files), and computational output (Gaussian format).

本文报道了双(噁唑啉基苯基)酰胺（bis(oxazolinylphenyl)amide, R-BOPA）配体支撑的钪配位化学。R-BOPA配体空间位阻过大，无法合成双酰胺基配合物[Sc(R-BOPA){N(SiMe3)2}2]；但将质子型配体与[Sc{N(SiMe3)2}2Cl]（1）反应，可得到混合酰胺基-氯配合物[Sc(R-BOPA){N(SiMe3)2}Cl]（2）。研究了配合物2中酰胺基与氯配体的选择性反应：尽管氯配体可通过复分解反应被干净脱除，但对N(SiMe3)2配体质子化时，会伴随R-BOPA配体的竞争性质子化。研究人员合成了配合物[Sc(R-BOPA)(CH2SiMe2Ph)2]（5）。所有含R-BOPA的配合物均以两种异构体形式存在。针对该平衡开展了实验与计算研究，数据表明苯环的协同旋转可实现两种非对映异构体间的相互转化。所有R-BOPA修饰的钪配合物均具有发光特性；借助含时密度泛函理论（Time-Dependent Density Functional Theory, TD-DFT）计算对光物理行为进行分析后发现，其发光源于配体中心发光，且两种异构体具有不同的发射寿命。本数据集包含所有实验光谱数据（如核磁共振（Nuclear Magnetic Resonance, NMR）数据）、晶体学数据（原始hl文件）以及高斯格式的计算输出文件。