Does the 18-Electron Rule Apply to CrSi12?

作者：Abreu Marissa Baddick; Reber Arthur C; Khanna Shiv N^*

来源：Journal of Physical Chemistry Letters, 2014, 5(20): 3492-3496.

DOI：10.1021/jz501868t

Understanding the bonding between silicon and transition metals is valuable for devising strategies for incorporating magnetic species into silicon. CrSi12 is the standard example of a cluster whose apparent high stability has been explained by the 18-electron rule. We critically examine the bonding and nature of stability of CrSi12 and show that its electronic structure does not conform to the 18-electron rule. Through theoretical studies, we find that CrSi12, has 16 effective valence electrons assigned to the Cr atom and an unoccupied 3d(z)(2) orbital. We demonstrate that the cluster%26apos;s apparent stability is rooted in a crystal field-like splitting of the 3d orbitals analogous to that of square planar complexes. CrSi14 is shown to follow the 18-electron rule and exhibits all conventional markers characteristic of a magic cluster.

• 出版日期2014-10-16