title: Chemical Bonding and σ-Aromaticity in Charged Molecular Alloys: [Pd2As14]4-and [Au2Sb14]4-Clusters.
abstract: We report a computational study on the structures and bonding of a charged molecular alloy D2h[Pd2As14]4-(1), as well as a model D2h[Au2Sb14]4-(2) cluster. Our effort makes use of an array of quantum chemistry tools: canonical molecular orbital analysis, adaptive natural density partitioning, natural bond orbital analysis, orbital composition analysis, and nucleus independent chemical shift calculations. Both clusters consist of two X7(X = As, Sb) cages, which are interconnected via a M2(M = Pd, Au) dumbbell, featuring two distorted square-planar MX4units. Excluding the Pd/As or Au/Sb lone-pairs, clusters 1 and 2 are 50- and 44-electron systems, respectively, of which 32 electrons are for two-center two-electron (2c-2e) As-As or Sb-Sb σ bonds and an additional 16 electrons in 1 for 2c-2e Pd-As σ bonds. No covalent Pd-Pd or Au-Au bond is present in the systems. Cluster 1 is shown to possess two globally delocalized σ electrons, whereas 2 has two σ sextets (each associated with an AuSb4fragment). Thus, 1 and 2 conform to the (4n + 2) Hückel rule, for n = 0 and 1, respectively, rendering them σ-aromaticity.
authors.affiliation: Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan, 030006, China.
authors.forename: Xue-Rui
authors.initials: XR
authors.lastname: You
authors.affiliation: Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan, 030006, China.
authors.forename: Lin-Yan
authors.initials: LY
authors.lastname: Feng
authors.affiliation: Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan, 030006, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan, 030006, China. hj.zhai@sxu.edu.cn.|State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan, 030006, China. hj.zhai@sxu.edu.cn.
authors.forename: Hua-Jin
authors.initials: HJ
authors.lastname: Zhai