Origin of the Ligand Ring‐Size Effect on the Catalytic Activity of Cationic Calcium Hydride Dimers in the Hydrogenation of Unactivated 1‐Alkenes

ABSTRACT: Abstract Recently, it was shown that the double Ca−H−Ca‐bridged calcium hydride cation dimer [LCaH2CaL]2+ when stabilized by a larger macrocyclic N,N’,N’’,N’’’,N’’’’‐pentadentate ligand showed evidently higher activity than when stabilized by a smaller N,N’,N’’,N’’’‐tetradentate ligand in the catalytic hydrogenation of unactivated 1‐alkenes. In this DFT‐mechanistic work, the origin of the observed ring‐size effect is examined in detail using 1‐hexene, CH2=CH2 and H2 as substrates. It is shown that, at room temperature, both the N,N’,N’’,N’’’,N’’’’‐stabilized dimer and the monomer are not coordinated by THF in solution, while the corresponding N,N’,N’’,N’’’‐stabilized structures are coordinated by one THF molecule mimicking the fifth N‐coordination. Catalytic 1‐alkene hydrogenation may occu

SUBMITTER: Zhu H 

PROVIDER: S-EPMC9756592 | biostudies-literature | 2022 Dec

REPOSITORIES: biostudies-literature