Assembly of One to Four As4_4 Analogues, (Ge2_2As2_2)2−^{2-} or (Ge3_3As)3−^{3-}, in the Coordination Sphere of [PhM]+^+, [MesM]+^+, or M2+^{2+} (M = Zn, Cd, Hg)

Pseudo-tetrahedral units of p-block atoms proved to be excellent building blocks for novel molecular architectures and for introducing new elemental combinations which are not otherwise accessible. In this work, we present a series of clusters obtained by reactions of binary Ge/As anions with [MPh2] (M=Zn, Cd, Hg; Ph=phenyl). The study is grounded on the fact that the binary reactant gained by extracting the solid ‘K2GeAs’ with ethane-1,2-diamine (en) co-exists as (Ge2As2)2− and (Ge3As)3− in solution. This allows for a larger variety of products by ‘selecting’ the most suitable species for the final ternary complex to crystallize. The reactions afforded the unprecedented first step of the corresponding interaction, thus attachment of (MPh)+ to a pseudo-tetrahedral unit in [PhZn(Ge3As)]2− (1) and [PhHg(Ge3As)]2− (2), and complex anions with two, three, or four units, [(Ge3As)Zn(Ge2As2)]3− (3), [Cd3(Ge3As)3]3− (4), and [Zn3(Ge3As)4]6− (5). Quantum chemistry confirmed the compositions and the positions of the Ge or As atoms, beside explaining structural peculiarities. The subtle impact of different [MR2] reactants was additionally studied by corresponding reactions using [ZnMes2] (Mes=mesityl), which showed success in selectively crystallizing [MesZn(Ge3As)]2− (6). Based on our findings, we derive a suggestion of the underlying reaction cascade

φ-Aromaticity in prismatic {Bi6_6}-based clusters

The occurrence of aromaticity in organic molecules is widely accepted, but its occurrence in purely metallic systems is less widespread. Molecules comprising only metal atoms (M) are known to be able to exhibit aromatic behaviour, sustaining ring currents inside an external magnetic field along M–M connection axes (σ-aromaticity) or above and below the plane (π-aromaticity) for cyclic or cage-type compounds. However, all-metal compounds provide an extension of the electrons’ mobility also in other directions. Here, we show that regular {Bi$_6$} prisms exhibit a non-localizable molecular orbital of f-type symmetry and generate a strong ring current that leads to a behaviour referred to as φ-aromaticity. The experimentally observed heterometallic cluster [{CpRu}$_3$Bi$_6$]–, based on a regular prismatic {Bi$_6$} unit, displays aromatic behaviour; according to quantum chemical calculations, the corresponding hypothetical Bi$_6$$^{2−}$ prism shows a similar behaviour. By contrast, [{(cod)Ir}$_3$Bi$_6$] features a distorted Bi$_6$ moiety that inhibits φ-aromaticity

Homoleptic Poly(nitrato) Complexes of Group 14 Stable at Ambient Conditions

Using a novel approach in homoleptic nitrate chemistry, Sn(NO3)62− (3c) as well as the previously unknown hexanitrato complexes Si(NO3)62− (1c), Ge(NO3)62− (2c) were synthesized from the element tetranitrates as salt-like compounds which were isolated and characterized using 1H, 14N, and 29Si NMR and IR spectroscopies, elemental and thermal analyses, and single-crystal XRD. All hexanitrates are moderately air-sensitive at 298 K and possess greater thermal stability toward NO2 elimination than their charge-neutral tetranitrato congeners as solids and in solution. The complexes possess distorted octahedral coordination skeletons and adopt geometries that are highly symmetric (3c) or deformed (1c, 2c) depending on the degree of steric congestion of the ligand sphere. As opposed to the κ2O,O′ coordination mode reported for Sn(NO3)4 previously,1 all nitrato ligands of 3c coordinate in κ1O mode. Six geometric isomers of E(NO3)62− were identified as minima on the PES using DFT calculations at the B3LYP/6-311+G(d,p) level of which two were observed experimentally

Homoleptic Low-Valent Polyazides of Group 14 Elements

First examples of coordinatively unsaturated, homoleptic azido complexes of low-valent group 14 elements are reported. A simple strategy uses low-valent precursors, ionic azide transfer reagents and bulky cations to obtain salt-like compounds containing E(N3)3- of Ge(II)/Sn(II) which are fully characterised, including XRD. Remarkably, these compounds are kinetically stable at r.t. and isolable in sub-gram quantities

Insight into the formation of bismuth-tungsten carbonyl clusters

Abstract Multimetallic clusters play a key role as models to doped metals, as candidates to new types of superatomic catalysts and as precursors to new multimetallic solids. Understanding formation pathways is an essential and necessary step forward in the development of cluster synthesis and research, yet remains considerably lacking owing to difficulty in identification of intermediates and the ill-defined nature of common starting materials. Here we show progress in this regard by investigating the reactivity of an intermetallic solid of nominal composition ‘K5Ga2Bi4’ with [W(cod)(CO)4] upon extraction with ethane-1,2-diamine (en) and 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane (crypt-222). Several polybismuthide intermediates and by-products were identified along the reaction pathway, ultimately forming the new polybismuthide salt [K(crypt-222)]3[µ:η3-Bi3{W(CO)3}2]∙en∙tol. DFT calculations revealed plausible reaction schemes for the transformations taking place in the reaction mixture providing insight into the complex reactivity of ‘K5Ga2Bi4’ on the basis of in situ generation of Bi2 2−

Comments on “Does φ-Aromaticity exist in prismatic {Bi6}-based clusters?”

We read the manuscript by Dariusz W. Szczepanik and Miquel Solà with interest, and recognized several misinterpretations (based on oversimplifications) of our work and also errors that results from inappropriate/insufficient methods applied in their follow-up studies. This led to erroneous statements, which the authors additionally mixed with statements on aromaticity, which does not fully comply with definitions that have been well-established, e.g., for benzene. In this comment, we outline the misinterpretations, errors, and questionable statements, thereby referring to our work and further literature to underline the facts