A Second Modification of Beryllium Bromide: β-BeBr₂

Abstract

The synthesis of a second beryllium bromide modification, β-BeBr 2 , was accomplished through recrystallization of α-BeBr 2 from benzene in the presence of cyclo-decamethylpentasiloxane. This phase was analyzed via single-crystal X-ray diffraction and IR and Raman spectroscopy as well as density functional theory calculations. This enabled a comparison to α-BeBr 2 and the α and β phases of beryllium chloride and iodide.

Beryllium‐Mediated Halide and Aryl Transfer onto Silicon

“…There is a correlation between the ring size of cyclosiloxanes and crown ethers concerning metal ion complexation. [5] For beryllium it is known that only [12]crown-4 can coordinate Be 2 + endo-cyclically via three of its four O-donor sites, [33,34] while [15]crown-5 [35] and [18]crown-6 only coordinate via two oxygen atoms in an exo-cyclic fashion. [36] Therefore, we reacted BeCl 2 , BeBr 2 , BeI 2 and [Be 3 Ph 6 ] with D 3 in the hope to either form beryllium complexes with D 3 or to reorganize the cyclosiloxane scaffold due to Si-O bond cleavage and reformation.…”

“…However, if the reaction mixtures are left standing for too long, an unidentified product mixture is formed. [18] This is presumably due to Si-O bond cleavage, as seen with partially silicon based crown ethers in the presence of BeCl 2 . [19] In general, little is known about beryllium siloxane and silanolate complexes due to the severe health hazards associated with beryllium and its compounds.…”

Trendbericht Festkörperchemie 2022

“…Buchner und von Hänisch haben β-BeBr 2 synthetisiert, die zweite Modifikation des Berylliumbromids. 1) Sie erhielten die Verbindung durch Rekristallisation von α-BeBr 2 aus Benzol in der Gegenwart von Cyclodecamethylpentasiloxan. Quantenchemischen Rechnungen zufolge ist die β-Modifikation von BeBr 2 wie bei BeCl 2 und BeI 2 stabiler als die jeweiligen α-Modifikationen.…”

Handling Beryllium, the Safe Way

“…13−16 Researchers have developed efficient routes for the synthesis of beryllium halides 17 and have found a new polymorph of BeBr 2 . 18 Scientists have studied the influence on structure and reactivity of beryllium compounds 19−21 as well as their reactivity in substrate activation. 22−27 Furthermore, various novel Be−element single 28,29 and multiple bonds 30,31 have been prepared, and their bonding situation was evaluated in depth.…”

“…Dubbed as the most toxic nonradioactive element, beryllium has been the focus of little fundamental research in the second half of the twentieth century . In the past two decades, however, beryllium chemistry has received significantly more interest. − This highly diverse field of research ranges from studies on fundamental compound classes like acido beryllates and amino and amido beryllium complexes − to investigations of the structure, properties, and reactivity of organo-beryllium compounds. − Researchers have developed efficient routes for the synthesis of beryllium halides and have found a new polymorph of BeBr 2 . Scientists have studied the influence on structure and reactivity of beryllium compounds − as well as their reactivity in substrate activation. − Furthermore, various novel Be–element single , and multiple bonds , have been prepared, and their bonding situation was evaluated in depth. − The groups of Braunschweig and Gilliard synthesized low-valent beryllium complexes and investigated their reactivity, − while the correct interpretation of the oxidation states in these compounds still receives attention. − …”