π-Complexation of Post-Transition Metals by Neutral Aromatic Hydrocarbons: The Road from Observations in the 19th Century to New Aspects of Supramolecular Chemistry

Abstract

Compounds of the elements in the three triads of post-transition metals, Ga-In-Tl, Ge-Sn-Pb, and As-Sb-Bi, form in their low-valence states a variety of stable complexes with neutral hydrocarbons. This chemistry is reviewed starting from the early discoveries in the 19th century and including the most recent contributions.

Well‐Defined Stibonic and Tellurinic Acids

“…The inorganic cores of 3 and 6 are effectively shielded by the bulky m-terphenyl substituents, which prevent further aggregation, while in 6 two mesityl groups in ortho position are engaged in Menshutkin type interactions with the lone pairs of the Te atoms (centroid (C20-C25)···Te1 3.399(1) ). [12] In 3 the equatorial and axial endocyclic Sb À O bond lengths (1.913(2) and 2.035(2) ) vary only marginally (by 0.122(2) ) and compare well with those of (Ph 3 SbO) 2 (1.928(3) and 2.071(4) ). [6] By contrast, in 6 the equatorial and axial endocyclic TeÀO bond lengths (1.897 (5) and 2.143(5) ) differ by 0.246(5) .…”

Supra-molecular synthons based on gold…π(arene) interactions

“…Not only do Au…Au interactions lead to fascinating supra-molecular architectures, the fact that the energy of stabilisation afforded to their crystal structures can match that provided by conventional hydrogen bonding [10] led to competition studies between these synthons [11][12][13][14]. By contrast, considerably less attention has been directed to ascertaining formation of Au…π(arene) interactions [15]; analogous interactions are well established in the supramolecular chemistry of the main group elements [16][17][18]. Herein, an overview of Au…π(arene) interactions, formed both intra-and inter-molecularly, operating in the crystal structures of molecular gold compounds is given, and their presence in macro-molecular structures is also discussed, along with future prospects for this type of interaction.…”

The Interplay between Various σ- and π-Hole Interactions of Trigonal Boron and Trigonal Pyramidal Arsenic Triiodides

“…Crystalline material was prepared accidentally during the attempts to synthesize a complex analogous to the previously published adducts of arenes and SbCl3 [22][23][24]. The exchange of the sodium cation from the borosilicate Simax ® glassware (Kavalierglass, a.s., Sázava, Czech Republic) and the arsenic atom obviously took place (see Figure 3).…”