Characterization of Magnetic Series of Iron-Carbon Clusters Fe nC0,±1 (n ¿ 13)

© 2020 American Chemical Society.The evolution of structural and electronic properties of neutral and charged iron clusters doped with a single carbon atom, FenC0,±1 (n = 1-13) series, is studied in this work, which has been carried out throughout all-electron density functional calculations at the BPW91/6-311++G(2d,2p) level of theory. The results indicate a redshift of the bands in the infrared spectra due to carbon-iron stretching because the cluster contains more iron atoms. The iron-carbon bond lengths and the iron-carbon-iron bond angle increase and the ionization energies decrease as the cluster size increases. Notably, the total spin multiplicity increases smoothly even with the inclusion of the carbon atom. Also, the spin from the additional carbon atom turns parallel in the larger species, contributing to the total magnetic moment. In the Fe6-9,12,13C0,±1 species, the carbon atom becomes tetravalent with a near-planar form. This unusual coordination between carbon and the iron core may be due to the lack of hybridization between the s and p orbitals of carbon and to the large iron-carbon bonds. The nearly straight iron-carbon-iron angles are due to the overlap, in occupied orbitals close to the highest occupied molecular orbital, among pure p orbitals and most of d orbitals of carbon and iron atoms, respectively.

Characterization of Magnetic Series of Iron-Carbon Clusters Fe nC0,±1 (n ¿ 13) Academic Article in Scopus