From Ylides to Doubly Yldiide-Bridged Iron(II) High Spin Dimers via Self-Protolysis.

ABSTRACT: A synthetic strategy for the preparation of novel doubly yldiide bridged iron(II) high spin dimers ([(?2-C)FeL]2, L = N(SiMe3)2, Mesityl) has been developed. This includes the synthesis of ylide-iron(II) monomers [(Ylide)FeL2] via adduct formation. Subsequent self-protolysis at elevated temperatures by in situ deprotonation of the ylide ligands results in a dimerization reaction forming the desired bridging ?2-C yldiide ligands in [(?2-C)FeL]2. The comprehensive structural and electronic analysis of dimers [(?2-C)FeL]2, including NMR, Mössbauer, and X-ray spectroscopy, as well as X-ray crystallography, SQUID, and DFT calculations, confirm their high-spin FeII configurations. Interestingly, the Fe2C2 cores display very acute Fe-C-Fe angles (averaged: 78.6(2)°) resulting in short Fe···Fe distances (averaged: 2.588(2) Å). A remarkably strong antiferromagnetic coupling between the Fe centers has been identified. Strongly polarized Fe-C bonds are observed where the negative charge is mostly centered at the ?2-C yldiide ligands.

SUBMITTER: Yogendra S 

PROVIDER: S-EPMC6750861 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature