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).

Research results based upon these data are published at http://dx.doi.org/10.1002/ejic.201600223