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The synthesis of beryllium halide etherates and the solution behavior in benzene, dichloromethane, and chloroform was studied by NMR, IR, and Raman spectroscopy. Mononuclear units of [BeX 2(L)2] (X = Cl, Br, I; L = Et2O, thf) were identified as the favorably formed species in solution. Treatment of the mononuclear diethyl ether beryllium halide adduct with one equivalent beryllium halide formed the dinuclear compounds [BeX 2(OEt2)]2 (X = Cl, Br, I). The solid-state structures of [BeCl2(thf)2] and [BeBr2(thf)2] have been determined by single crystal X-ray diffraction analysis. [BeI2(thf)2] decomposed in all solvents. In CD2Cl2 the salt [Be(thf)4]I2 was formed, whereas in C6D6 and CDCl3, BeI2 precipitated and [BeI(thf)3]+, [Be(thf)4]2+ together with the thf ring-opening product [Be(μ 2-O(CH2)4I)I(thf)]2 were observed in solution.

Dissociation and ligand exchange processes at mono- and dinuclear beryllium phosphine were studied. This revealed significantly different processes, which are strongly dependent on solvent and ligand and are accountable for their varied reactivity.

The bonding situation in the tricoordinated beryllium phenyl complexes [BePh

Funding Information: We thank the Deutsche Forschungsgemeinschaft for funding. T.G. thanks the HPC-EUROPA3 (INFRAIA-2016-1-730897) for a travel grant and the computing resources provided by CSC, the Finnish IT Center for Science. Publisher Copyright: © 2022 American Chemical Society. All rights reserved. The reaction of the uranium(IV) halides UCl4, UBr4, or UI4 with ethyl acetate (EtOAc) leads to the formation of the complexes [UX3(EtOAc)4][UX5(EtOAc)] (X = Cl, Br) or [UI4(EtOAc)3]. Thus, both UCl4 and UBr4 show self-ionization in ethyl acetate to a distorted pentagonal bipyramidal [UX3(EtOAc)4]+ cation and a distorted octahedral [UX5(EtOAc)]- anion. Surprisingly, the chloride and bromide compounds are not isotypic. While [UCl3(EtOAc)4][UCl5(EtOAc)] crystallizes in the orthorhombic crystal system, space group P212121 at 250 K, the bromide compound crystallizes in the monoclinic crystal system, P121/n1 at 100 K. Unexpectedly, UI4 does not show self-ionization but forms [UI4(EtOAc)3] molecules, which crystallize in the monoclinic crystal system, P21/c, at 100 K. The compounds were characterized by single-crystal X-ray diffraction, IR, Raman, and NMR spectroscopy, as well as molecular quantum chemical calculations using solvent models.

The synthesis of bis(diphenylphosphino)ethane (dppe) and PMe3 mono-adducts [(dppe)BeCl2]n and [(PMe3)BeCl2]2 is described and their spectroscopic properties discussed. Hydrolysis of these two compounds and of the bis(diphenylphosphino)propane (dppp) adduct to BeCl2 gave [dppeH2][BeCl4], [Me3PH]n[Be4Cl9]n and [dpppH2][Be2Cl6], which have been isolated and structurally characterized by single crystal X-ray diffraction. The reactions of [(PMe3)BeCl2]2 with p-cresole gave [Me3PH]2[Be2Cl4(OC7H7)2]. This phenoxide together with [(Me3PO)2Be2Cl4], the oxidation product of [(PMe3)BeCl2]2, have also been structurally characterized.

The diphenylphosphinites [(THF)Li(OPPh2)]4 and [(THF)2Be(OPPh2)2] have been synthesized via direct deprotonation of diphenylphosphine oxide with n BuLi and BePh2, respectively, as well as via salt metathesis. These compounds were characterized by multinuclear NMR spectroscopy, and the side-products of the reactions obtained under various reaction conditions have been identified. The beryllium derivative could not be isolated and decomposed into diphosphine oxide Ph2PP(O)Ph2. The solid-state structure of this final product together with that of [(THF)Li(OPPh2)]4 have been determined by single-crystal X-ray diffraction.

A series of brightly colored (“pantochromic”) alkaline earth metal 1,3-dimethylviolurates AE(Me2Vio)2 have been prepared and fully characterized.

The suitability of ethylenediamine (en) as an alternative solvent to liquid ammonia in beryllium chemistry was evaluated. Therefore, BeF2, BeCl2, BeBr2, BeI2, [Be(NH3)4](N3)2, [Be(NH3)4](CN)2 and [Be(NH3)4](SCN)2 were reacted with ethylenediamine and analysed via NMR and IR spectroscopy. Additionally single crystal structures of [BeF2(en)]n, [Be(en)3]Cl2, [Be(en)3]Br2, [Be(en)2]I2·en, [Be(en)2](N3)2·en, [Be(en)2]4(SCN)7Cl and [Be3(OH)3(en)3][C2H9N2](SCN)4 were obtained. The anions were found to have a distinct influence on the solubility as well as on the species present in solution and the solid state, while ethylenediamine can act as mono- and bidentate ligand or as a crystal solvent.

The synthesis of a second beryllium bromide modification, β-BeBr2, was accomplished through recrystallization of α-BeBr2 from benzene in the presence of cyclo-decamethylpentasiloxane. This phase wa...

The solution behavior of beryllium halides and triflate in acetonitrile was studied by NMR, IR and Raman spectroscopy. Thereby mononuclear units [(MeCN)2BeX 2] (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)BeX 2]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.

Double bonds have been realized for a wide variety of elements in the p-, d-, and f-blocks. However, no s-block metal complexes with a double bond have been identified. Here we report the synthesis...

Beryllium and BeCl2 were treated with trifluoromethanesulfonic acid and trimethylsilyltriflate, respectively to form beryllium triflates BeL2(OTf)2 (L=H2O, THF, n Bu2O). The Be–O atomic distances (1.605–1.635 Å) between Be2+ and the triflate anions in solid state are the shortest known distances of this kind in a metal triflate yet. Attempts to remove the solvate molecules led to the decomposition of the obtained compounds.

Beryllium has long been considered the most toxic non-radioactive element to humans. However, it is shown that the acute toxicity of beryllium ions does not exceed that of other toxic cations like Cd2+, Ba2+, Hg2+ or As3+. The physiological mechanisms liable for the development of beryllium-associated diseases are discussed. Additionally an overview over proposed low-molecular model system for the beryllium species responsible for beryllioses is presented.

Beryllium metal was dissolved in liquid ammonia at ambient temperature through addition of alkali metals. Thereby, the amidoberyllates Cs[Be(NH2)3], [Na4 (NH2)2][Be(NH2)4] and K4[Be2O(NH2)4][Be(NH2)3]2 were isolated and structurally characterized via single crystal X-ray diffraction. In the case of Li we were able to synthesize Be(NH2)2 at ambient temperature. We present the first example of a [Be(NH2)4]2− anion as well as the first oxyamidoberyllate anion [Be2O(NH2)4]2−.

NEt3 adducts to BeCl2, BeBr2 and BeI2 were synthesized and characterised via NMR and IR spectroscopy as well as X-ray diffractometry. Depending on the halide and the state of matter these are either mono- or dinuclear. Population analyses were performed to determine the influence of the metal's partial charge on the coordination geometry. Additionally, the reactivity of these compounds towards C–Cl- and O–H-bonds was studied.

The hexa-μ2-amido-tetraammine-tetraberyllium compounds [Be4(NH2)6(NH3)4]X2 (X = Cl, Br, I, CN, SCN, N3) have been prepared from beryllium metal and NH4X or [Be(NH3)4]X2 in liquid ammonia at ambient temperature. The obtained compounds feature an adamantyl shaped complex cation, which was examined via X-ray diffraction, IR, Raman and NMR spectroscopy. The speciation in solution was studied via15N labeling experiments supplemented with quantum chemistry. Hereby, the intermediates [Be2(NH2)(NH3)6]3+ and [Be3(NH2)3(NH3)6]3+ were identified. Reactivity studies provided bis(N-acetimidoylacetamidinato-N,N′)-beryllium(ii), when [Be4(NH2)6(NH3)4]2+ was treated with acetonitrile. While the unprecedented octa-nuclear complex cation [Be8O(NH2)12(C5H5N)4]2+ was received from pyridine. This cluster proves that the [Be4O]6+ core can be stabilized without bidentate O-donor ligands., The boundaries of beryllium metal oxidation in acidic ammonia have been explored. This enabled the isolation of the tetra- and octa-nuclear beryllium amide complexes. The latter exhibits a completely new structural motive in coordination chemistry.

The interplay of metal ions with polysaccharides is important for the immune recognition in the lung. Due to the localization of beryllium associated diseases to the lung, it is likely that beryllium carbohydrate complexes play a vital role for the development of berylliosis. Herein, we present a detailed study on the interaction of Be2+ ions with fructose and glucose as well as simpler biomimetic ligands, which emulate binding motives of saccharides. Through NMR and IR spectroscopy as well as single‐crystal X‐ray diffraction, complemented by competition reactions we were able to determine a distinctive trend in the binding affinity of these ligands. This suggests that under physiological conditions beryllium ions are only bound irreversibly in glycoproteins or polysaccharides if a quasi ideal tetrahedral environment and κ4‐coordination is provided by the respective biomolecule. Furthermore, Lewis acid induced conversions of the ligands and an extreme increase in the Brønstedt acidity of the present OH‐groups imply that upon enclosure of Be2+, alterations may be induced by the metal ion in glycoproteins or polysaccharides. In addition the frequent formation of Be‐O‐heterocycles indicates that multinuclear beryllium compounds might be the actual trigger of berylliosis. This investigation on beryllium coordination chemistry was supplemented by binding studies of selected biomimetic ligands with Al3+, Zn2+, Mg2+, and Li+, which revealed that none of these beryllium related ions was tetrahedrally coordinated under the give conditions. Therefore, studies on the metabolization of beryllium compounds cannot be performed with other hard cations as a substitute for the hazardous Be2+., Beryllium chemistry: A detailed study on the interaction of saccharide‐mimicking ligands with Be2+ delivered the first comprehensive knowledge on the preferred binding environment around Be ions in polysaccharides and glycoproteins (see graphic). Additional experiments enabled elucidation of beryllium‐induced alterations in biomolecules, which sheds light on the biochemical mechanisms liable for the development of berylliosis.

It is common knowledge that metal-to-ligand π back-donation requires filled atomic orbitals at the metal center. However, we show through a combined experimental and theoretical approach that Be(II)→N-heterocyclic carbene (NHC) π back-donation is present in the two carbene adducts [(iPr)BeBr

We report the synthesis and crystal structure of the first quinolino[7,8

Alkaline earth metal catalysis has been a growing field in recent years. To enhance reactivity and to understand the metal-substrate interactions in more detail, reactions are increasingly carried out in weakly coordinating solvents. This article gives an overview over the two main approaches to facilitate this, which are either through the employment of highly dipolar haloaryls as solvents, or by increasing the solubility of the ligand systems. The resulting coordination modes and reactivities are presented together with the synthetic strategies. Additionally, the latest results of group 1 complex chemistry in aliphatic solvents are illustrated and future challenges are highlighted.

Aluminum-based adjuvants for vaccines and beryllium ions interact with the same immune receptor. The Be4O core, which is also found in beryllium oxocarboxylates, has been proposed to be the binding species in the latter case. However, this is not proven due to a lack of suitable probes for the Be4O moiety. Therefore, a versatile synthetic route to beryllium oxocarboxylates has been developed to investigate the steric and electronic influence of the ligands onto their molecular and spectroscopic properties. The oxocarboxylates exhibit extremely narrow line widths in 9Be NMR spectroscopy, and the chemical shift is only influenced by the sterics of the ligands. The mean variation of the atomic distances in the central Be4O building block is extremely small over all investigated compounds, and even the C-C distances are only little perturbed by the properties of the ligands. Vibrational spectroscopy showed Be-O bands; however, further distinctions could not be drawn.

Aldehydes play a key role in the human metabolism. Therefore, it is essential to know their reactivity with beryllium compounds in order to assess its effects in the body. The reactivity of simple aldehydes towards beryllium halides (F, Cl, Br, I) was studied through solution and solid‐state techniques and revealed distinctively different reactivities of the beryllium halides, with BeF2 being the least and BeI2 the most reactive. Rearrangement and aldol condensation reactions were observed and monitored by in situ NMR spectroscopy. Crystal structures of various compounds obtained by Be2+‐catalyzed cyclization, rearrangement, and aldol addition reactions or ligation of beryllium halides have been determined, including unprecedented one‐dimensional BeCl2 chains and the first structurally characterized example of an 1‐iodo‐alkoxide. Long‐term studies showed that only aldehydes without a β‐H can form stable beryllium complexes, whereas other aldehydes are oligo‐ and polymerized or decomposed by beryllium halides.

Electrospray ionization mass spectrometry (ESI MS) is a powerful technique for the study of coordination complexes because of its ability to analyze solution systems involving very low concentrations of metal complexes. In this work, the coordination chemistry of Be ions with a selection of well-known 1,3-diketone and related 1,2-diketone ligands has been investigated using ESI MS. With acetylacetone (Hacac), a range of acac-containing ions is observed, including [Be(acac)2H]+, [Be(acac)(MeOH) n]+ ( n = 1, 2), and polynuclear species such as the dinuclear [Be2(acac)3]+ and trinuclear [Be3O(acac)3]+. Density functional theory calculations indicate that the latter species has a central Be3(μ3-O) core, with each Be chelated (as opposed to being bridged) by an acac ligand. The effect of changing the substituents on 1,3-diketone was explored by an investigation of mixtures of Be2+ with other 1,3-diketones such as dibenzoylmethane (Hdbm), where the [Be(dbm)2H]+ ion showed a lesser tendency to undergo fragmentation and aggregation processes. Comparisons with the corresponding aluminum acetylacetone system were also made. In contrast, mixtures of Be2+ and the 1,2-diketones diacetyl and phenanthrenequinone showed poor metal-ligand interactions. Be2+ interacted with the 1,2-diketone benzil [PhC(O)C(O)Ph], forming the [Be(benzil) n]2+ ( n = 2-4) ions. The synthesis (from BeCl2) and X-ray structures of the dibenzoylmethanato (dbm) complex Be(dbm)2 and the benzil complex [BeCl2(benzil)] are also reported.

Tetraammineberyllium halides and pseudo-halides [Be(NH3)4]X2 (X = Cl, Br, I, CN, SCN, N3) as well as Be(NH3)2F2 have been prepared from beryllium metal and NH4X or NH4F in liquid ammonia at ambient temperature, respectively. Diammineberyllium halides Be(NH3)2X'2 (X' = Cl, Br, I) were synthesized at 300 °C from Be and NH4X'. The obtained compounds were characterised via X-ray diffraction, and IR and Raman spectroscopy and their thermal decomposition was studied by TGA.

The synthesis of a second beryllium bromide modification, β-BeBr

This paper studies the magnetic moment of the stable nucleus ${}^{207}$Pb by Nuclear Magnetic Resonance (NMR) measurements.By combining complex chemistry in the preparation of the $[{\mathrm{PbF}}_{6}{]}^{2\ensuremath{-}}$, sensitive NMR measurements, and highly accurate relativistic calculations of the shielding corrections, the authors show an improved value.

The first synthesis of BePh2 was accomplished almost a century ago. However, its structure has remained unknown so far, while the corresponding aryls of the elements adjacent to beryllium in the periodic table are well investigated. Herein, we present an improved synthesis for diphenylberyllium and show by X‐ray diffraction that it forms a trinuclear complex in the solid state. NMR spectroscopy revealed that this structure is also retained in solution but exhibits dynamic behavior. Its stability against heat and coordinating solvents is discussed and the possible obstacles to the synthesis of BePh2 from BeCl2 are examined. In the process of this study two ether adducts, BePh2⋅Et2O and Be2Ph4⋅Et2O, have been characterized as well as the previously unknown triphenylberyllate anion. From the latter several single‐crystal structures were obtained under various conditions, in which [BePh3]− is either isolated or acts as a ligand for Li+. Furthermore, the crown ether induced selfionization of BePh2 is described and the resulting [(12‐crown‐4)BePh]+ cation was isolated, which shows an unusual 4+1 coordination around the Be atom., Finally, the structure of diphenylberyllium has been determined and its reactivity explored. BePh2 acts as a Lewis acid but with unexpectedly low ether‐affinity. Several triphenylberyllates were characterized, of which one originates from the selfionization of BePh2. The generated phenylberyllium cation exhibits an unusual 4+1 coordination and all compounds are stable in chlorinated solvents (see scheme). These findings enabled a classification of organoberyllium compounds in comparison to the other (pseudo)main group organyles.

The activation of C–Cl bonds in dichloromethane and chloroform was observed by BeCl2 in the presence of PMe3 and PCy3. This leads to the formation of [Me3PCH2Cl]Cl and [Cy3PCHCl2][BeCl3]. The latter compound is the first example of a tricoordinated beryllium species with nonbulky ligands and proof of the existence and stability of the long-predicted [BeCl3]− ion. In analogy to the isoelectronic BCl3, the trichloroberyllate anion exhibits Lewis acidic behavior toward electron-pair donors and was probed for the electronic and steric influence of the Lewis base. [BeCl3]− can also act as a chloride ion donor or acceptor, leading to the formation of neutral phosphane adducts to BeCl2 and [BeCl4]2–. The existing equilibria between these species were investigated and showed high chloride mobility.

Invited for the cover of this issue is the group of Magnus R. Buchner at Philipps-Universität Marburg. The image depicts a piece of beryllium decomposing sugar cubes. Read the full text of the article at 10.1002/chem.201903439.

The coordination mode around beryllium in proteins and the binding affinity towards the peptide are unknown because there have been no coordination compounds of beryllium with ligands bearing bio-relevant functional groups. We report the first comprehensive study on Be complexes with monodentate carboxylic acids, esters, aldehydes, and alcohols. Through solution and solid-state techniques we determined that the binding affinities of Be2+ ions towards the functional groups are: carboxylate > alcohol > aldehyde > ester. Crystal structures of all the compounds have been determined including the unprecedented dodeca-nuclear macrocyclic ring structure of non-basic beryllium benzoate, which is the first example of those beryllium carboxylates. These findings enable the evaluation of potential beryllium binding sites inside proteins and is required to understand the mechanism of metal-triggered immune responses.

Here we present a facile synthesis for anhydrous BeCl2, BeBr2 and BeI2 from the elements under mild conditions. While this method delivers pure BeI2 directly, BeCl2 and BeBr2 were further purified by vacuum sublimation. Complete sets of solid state IR and Raman spectroscopic and X-ray powder diffraction data of these beryllium halides were collected including the previously missing IR and Raman spectra of BeBr2 and BeI2. All halides were additionally investigated by quantum chemical calculations. This allowed an assignment of the IR and Raman modes, which had never been done before on any beryllium halide and allowed interpretation of the experimental data as well as the differentiation of polymorphs.

Starting from the respective metal, we have synthesized the binary hexafluorides MF6 of M = Mo, Os, Ir, Te, and U by the use of a remote fluorine plasma source using a mixture of Ar and NF3 as the feed gas. The formation of the binary hexafluorides was confirmed by several different spectroscopic methods including IR, Raman, UV/VIS, and NMR spectroscopy.

We have reacted β-uranium(V) fluoride with liquid anhydrous hydrogen cyanide and obtained a 1D coordination polymer with the composition ["U" "F" _"5" ("HCN" )_"2" ], (_"∞" ^"1" )"[U" "F" _"4/1" "F" _"2/2" ("HCN" )_"2/1" "]" , revealed by single crystal X-ray structure determination. The reaction system was furthermore studied by means of vibrational and NMR spectroscopy, as well as by quantum chemical calculations. The compound presents the first described polymeric HCN Lewis adduct and the first HCN adduct of a uranium fluoride.