Beryllium chloride
{{chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 470445523
| Name = Beryllium chloride
| ImageFile = BeCl2polymer.png
| ImageFile1 = EntryWithCollCode92585.png
| ImageSize1 = 250px
| ImageFile2 = EntryWithCollCode92587.png
| ImageSize2 = 250px
| IUPACName = Beryllium chloride
| Section1 = {{Chembox Identifiers
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 22991
| InChI = 1/Be.2ClH/h;2*1H/q+2;;/p-2
| InChIKey = LWBPNIJBHRISSS-NUQVWONBAX
| SMILES = [Be+2].[Cl-].[Cl-]
| SMILES_Comment = ionic depiction
| SMILES1 = Cl[Be]Cl
| SMILES1_Comment = covalent monomer
| SMILES2 = Cl[Be-2](Cl)([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1([Cl+]1)[Cl+][Be-2]1(Cl)Cl
| SMILES2_Comment = polymer
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/Be.2ClH/h;2*1H/q+2;;/p-2
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = LWBPNIJBHRISSS-UHFFFAOYSA-L
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 7787-47-5
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 58B7024067
| PubChem = 24588
| RTECS = DS2625000
}}
| Section2 = {{Chembox Properties
| Formula = BeCl2
| MolarMass = 79.9182 g/mol
| Appearance = White or yellow crystals
| Density = 1.899 g/cm3, solid
| Solubility = 15.1 g/100 mL (20 °C)
| MeltingPtC = 399
| BoilingPtC = 482
| SolubleOther = soluble in alcohol, ether, benzene, and pyridine
slightly soluble in chloroform and sulfur dioxide
}}
| Section3 = {{Chembox Structure
| CrystalStruct = hexagonal
| MolShape = polymer
| Dipole =
}}
| Section4 = {{Chembox Thermochemistry
| DeltaHf = −6.136 kJ/g or −494 kJ/mol
| DeltaHc = 16 kJ/mol
| DeltaGf = −468 kJ/mol
| Entropy = 63 J/mol K
| HeatCapacity = 7.808 J/K or 71.1 J/mol K
}}
| Section7 = {{Chembox Hazards
| LD50 = 86 mg/kg (rat, oral)
| REL = Ca C 0.0005 mg/m3 (as Be){{PGCH|0054}}
| PEL = TWA 0.002 mg/m3
C 0.005 mg/m3 (30 minutes), with a maximum peak of 0.025 mg/m3 (as Be)
}}
| Section8 = {{Chembox Related
| OtherAnions = Beryllium fluoride
Beryllium bromide
Beryllium iodide
| OtherCations = Magnesium chloride
Calcium chloride
Strontium chloride
Barium chloride
Radium chloride
}}
}}
Beryllium chloride is an inorganic compound with the formula BeCl2. It is a colourless, hygroscopic solid that dissolves well in many polar solvents. Its properties are similar to those of aluminium chloride, due to beryllium's diagonal relationship with aluminium.
Structure and synthesis
Beryllium chloride is prepared by reaction of the metal with chlorine at high temperatures:Irving R. Tannenbaum "Beryllium Chloride" Inorganic Syntheses, 1957, vol. 5, p. 22. {{doi|10.1002/9780470132364.ch7}}
:Be + Cl2 → BeCl2
BeCl2 can also be prepared by carbothermal reduction of beryllium oxide in the presence of chlorine.Cotton, F. A.; Wilkinson, G. (1980) Advanced Inorganic Chemistry John Wiley and Sons, Inc: New York, {{ISBN|0-471-02775-8}}. BeCl2 can be prepared by treating beryllium with hydrogen chloride.
Two forms (polymorphs) of BeCl2 are known. Both structures consist tetrahedral Be2+ centers interconnected by doubly bridging chloride ligands. One form consist of edge-sharing polytetrahedra. The other form resembles zinc iodide with interconnected adamantane-like cages.{{cite journal|author=Troyanov, S.I.|title=Crystal Modifications of Beryllium Dihalides BeCl2, BeBr2 and BeI2|journal=Zhurnal Neorganicheskoi Khimii|year=2000|volume=45|page=1619-1624}} In contrast, BeF2 is a 3-dimensional polymer, with a structure akin to that of quartz.
In the gas phase, BeCl2 exists both as a linear monomer and a bridged dimer with two bridging chlorine atoms where the beryllium atom is 3-coordinate.{{Greenwood&Earnshaw}} The linear shape of the monomeric form is as predicted by VSEPR theory. The linear shape contrasts with the monomeric forms of some of the dihalides of the heavier members of group 2, e.g. CaF2, SrF2, BaF2, SrCl2, BaCl2, BaBr2, and BaI2, which are all non-linear. Beryllium chloride dissolves to give tetrahedral [Be(OH2)4]2+ ion in aqueous solutions as confirmed by vibrational spectroscopy.{{cite journal |doi=10.1039/B902481F|title=Hydration of Beryllium(II) in Aqueous Solutions of Common Inorganic Salts. A Combined Vibrational Spectroscopic and ab initio Molecular Orbital Study|year=2009|last1=Rudolph|first1=Wolfram W.|last2=Fischer|first2=Dieter|last3=Irmer|first3=Gert|last4=Pye|first4=Cory C.|journal=Dalton Transactions|issue=33|pages=6513–6527|pmid=19672497}}
Reactions
When treated with water, beryllium chloride forms a tetrahydrate, BeCl2•4H2O ([Be(H2O)4]Cl2). BeCl2 is also soluble in some ethers.{{RubberBible87th}}Holleman, A. F.; Wiberg, E. (2001) Inorganic Chemistry Academic Press: San Diego, {{ISBN|0-12-352651-5}}
When suspended in diethyl ether, beryllium chloride converts to the colorless dietherate:{{cite journal |doi=10.1515/znb-2023-0303 |title=Structure and Spectroscopic Properties of Etherates of the Beryllium Halides |date=2023 |last1=Bekiş |first1=Deniz F. |last2=Thomas-Hargreaves |first2=Lewis R. |last3=Berthold |first3=Chantsalmaa |last4=Ivlev |first4=Sergei I. |last5=Buchner |first5=Magnus R. |journal=Zeitschrift für Naturforschung B |volume=78 |issue=3–4 |pages=165–173 }}
:{{chem2|BeCl2 2 O(C2H5)2 → BeCl2(O(C2H5)2)2}}
This ether ligand can be displaced by other Lewis bases.
Beryllium chloride forms complexes with phosphines.{{Cite journal |last1=Buchner |first1=Magnus R. |last2=Müller |first2=Matthias |last3=Rudel |first3=Stefan S. |date=2017-01-19 |title=Beryllium Phosphine Complexes: Synthesis, Properties, and Reactivity of (PMe3)2BeCl2 and (Ph2PC3H6PPh2)BeCl2 |url=https://onlinelibrary.wiley.com/doi/10.1002/anie.201610956 |journal=Angewandte Chemie International Edition |language=en |volume=56 |issue=4 |pages=1130–1134 |doi=10.1002/anie.201610956|pmid=28004465}}
Applications
Beryllium chloride is used as a raw material for the electrolysis of beryllium, and as a catalyst for Friedel-Crafts reactions.
References
External links
- [http://webbook.nist.gov/cgi/cbook.cgi?ID=C7787475&Units=SI Properties of BeCl2] from NIST
{{Beryllium compounds}}
{{Chlorides}}