Behavior of beryllium halides and triflate in acetonitrile solutions

Abstract

The solution behavior of beryllium halides and triflate in acetonitrile was studied by NMR, IR and Raman spectroscopy. Thereby mononuclear units [(MeCN)2BeX2] (X = Cl, Br, I, OTf) were identified as dominant species in these solutions. The solid state structure of [(MeCN)2Be(OTf)2] has been determined by X-ray diffraction. If only one equivalent of MeCN is used the dinuclear compounds [(MeCN)BeX2]2 (X = Cl, Br, I) are formed. Partial halide and triflate dissociation into the monomeric complexes as well as the formation of hetero-halide complexes [(MeCN)2BeClBr], [(MeCN)2BeClI] and [(MeCN)2BeBrI] was observed.

Dimethylsulfide Adducts of the Beryllium Halides

“…We are interested in the speciation of beryllium compounds in solution [23–26] . For this reason, we have already investigated the beryllium halide adducts of O ‐donor solvents like carboxylic acid esters [27] and dimethylformamide [28] as wells as of the N ‐donor solvents ammonia, [29,30] ethylienediamine, [31] triethylamine [32] and acetonitrile [33] . Therefore, it made sense to extend this research into thioether adducts, especially due to the apparently weak Be−S bond strength, [22] which makes them promising precursors for beryllium alkyles.…”

Steric Influence on the Constitution of Beryllium Phosphine Complexes

“…This signal presumably originates from the PPh 3 adduct of a mixed beryllium chloride iodide species. Such beryllium species are known for halido beryllates [23] and also for acetonitrile adducts [25] . After three weeks of storage at ambient temperature the 9 Be NMR signal of 6 c had disappeared and only one broad signal at 4.6 ppm could be observed, which presumably originates from various mixed chloride iodide species with higher chlorine content than the species in the initial spectrum.…”

Synthesis and Derivatives of Beryllium Triflate

“…NMR Spectroscopy. 1 H, 9 Be, 13 C, 19 F, and 29 Si NMR spectra were recorded on Bruker AVANCE III HD 300 and AVANCE III 500 NMR spectrometers. The latter was equipped with a Prodigy CryoProbe.…”

“…The latter was equipped with a Prodigy CryoProbe. 1 H NMR (300/500 MHz) and 13 C NMR (76/126 MHz) chemical shifts are given relative to the solvent signal for CD 2 Cl 2 (5.32 and 53.8 ppm)/CDCl 3 (7.26 and 77.2 ppm), while 9 Be NMR (42 MHz), 19 F NMR (283 MHz), and 29 Si NMR (60 MHz) used 0.43 [M] BeSO 4 in D 2 O, neat CFCl 3 , and neat SiMe 4 as an external standard, respectively. NMR spectra were processed with the MestReNova software package.…”

“…However, even though alkaline earth metal triflates have been known for decades, there are no reports on the existence of beryllium triflate. The reason for the lack of reports on beryllium triflate might be the high oxophilicity of Be 2+ , which renders most known synthetic approaches to metal triflates inappropriate, , since water or organic donor solvents cannot be removed from the beryllium center under conditions which keep the triflate group intact. , However, considering the high ion potential of beryllium, this should be one of the strongest purely metal-based Lewis acids. Hence, we investigated various synthetic approaches toward homoleptic beryllium triflate and its coordination chemistry.…”