Complexation behaviour of LiCl and LiPF6 – model studies in the solid-state and in solution using a bidentate picolyl-based ligand

Structural knowledge on ubiquitous lithium salts in solution and in the crystalline state is of paramount importance for our understanding of many chemical reactions and of the electrolyte behaviour in lithium ion batteries. A bulky bidentate Si-based ligand (6) was used to create simplified model systems suitable for correlating structures of LiCl and LiPF6 complexes in the solid-state and in solution by combining various experimental, spectroscopic, and computational methods. Solution studies were performed using 1H DOSY, multinuclear variable temperature NMR spectroscopy, and quantum chemical calculations. [Ph2Si(2-CH2Py)2·LiCl]2 (3) dissociates into a monomeric species (9) in THF. For [Ph2Si(2-CH2Py)2·LiPF6]2 (11), low temperature NMR studies revealed an unprecedented chiral coordination mode (12) in non-coordinating solvents

Recent advances in the applications of metal-ligand cooperation via dearomatization and aromatization of pincer complexes

Metal-ligand cooperation (MLC) has played an important role in the development of new green homogeneous catalytic reactions. In the past we have discovered a new mode of MLC which is based on the dearomatization and aromatization of pincer complexes and have utilized it to uncover new modes of bond activation and new catalytic reactions that are atom-economic, environmentally benign and sustainable. Building upon our earlier discoveries which have been well-reviewed in the past, this chapter discusses recent progresses on the application of the concept of MLC via dearomatization and aromatization of pincer complexes. Bond activation of greenhouse gases such as CO2 and N2O and their applications in the development of catalytic reactions have been discussed in detail. Additionally, the new concept of template catalysis where catalytic transformation occurs mainly on the pincer ligand and the metal centre acts as an “anchor” has also been discussed. Template catalysis utilizes the tool of MLC via dearomatization/aromatization to perform Michael reactions forming new C–C, C–O and C–N bonds catalysed by ruthenium, rhenium and manganese pincer complexes. © 2020, Springer Nature Switzerland AG