Designing 3-D Molecular Stars

Abstract

We have explored in detail the potential energy surfaces of the Si(5)Li(n)(5-6) (n = 5-7) systems. We found that it is feasible to design three-dimensional star-like silicon structures using the appropriate ligands. The global minimum structure for Si(5)Li(7)(+) has a perfect seven-peak star-like structure. The title compounds comprise, essentially, the Si(5)(6-) ring interacting with lithium cations. The ionic character of the Si-Li interactions induces the formation of a bridged structure. Concomitantly, our calculations show that the reduction of the Pauli repulsion and the maximization of the orbital contribution are also significant for the star-like structure formation. Additionally, the MO analysis of the systems suggests that the role of the lithium atoms is to provide the precise number of electrons to the central Si(5) unit. This is confirmed by the magnetic properties, which show that electron delocalization enhances the stability of the star-like structures proposed here.

Li7(BH)5+: a new thermodynamically favored star-shaped molecule

“…However, they are just local minima on their corresponding PES, 20,24 and therefore impractical targets for experimental detection. We have theoretically designed a stable silicon-based C 5 H 5 analogue: the Li 7 Si 5 + (D 5h ) cluster, which is a star-like molecule in its lowest energy conformation.…”

“…We have theoretically designed a stable silicon-based C 5 H 5 analogue: the Li 7 Si 5 + (D 5h ) cluster, which is a star-like molecule in its lowest energy conformation. 20 Subsequently, it has unequivocally been shown that the five-pointed star shape is a common structural pattern for minimum energy conformation of Li 7 E 5 + (E = C, Si, and Ge). 25,26 This unusual high-symmetry pattern is favored by i) the aromaticity in the central fivemembered ring, and by ii) the preference by Li atoms for bridging positions.…”

Sub‐Nano Clusters: The Last Frontier of Inorganic Chemistry

“…In fact, cluster design based on chemical bonding already has successful precedents Galeev et al 2012;Tiznado et al 2009;Zhang and Alexandrova 2013). We, as a community, are in the privileged position to write a new textbook chapter on the chemistry of clusters.…”

Singly and doubly lithium doped silicon clusters: Geometrical and electronic structures and ionization energies

“…27 Interestingly, the multi-lithium doped silicon cluster Si 5 Li 7 was predicted to have a perfect seven-peak star-like structure due to the electron donation behavior of the Li atoms. 28 Some experimental data on sodium doped silicon clusters, including threshold photoionization and photoelectron spectroscopy studies, are available. [29][30][31][32] However, not many experiments are reported for the lithium congener.…”