Wikipedia:WikiProject Chemicals/Chembox validation/VerifiedDataSandbox and Beryllium hydride: Difference between pages

{{for|the monohydride|Beryllium monohydride}}

|Verifiedfields = changed

|Watchedfields = changed

|verifiedrevid = 470456352

|Name = Beryllium hydride

|ImageFile = Beryllium-hydride-3D-balls.png

|ImageSize = 230px

|OtherNames = Beryllium dihydride<br>Beryllium hydride<br>Beryllane

|Section1={{Chembox Identifiers

|InChI = 1/Be.2H/rBeH2/h1H2

|InChIKey = RWASOQSEFLDYLC-JICJMJRQAQ

|ChEBI_Ref = {{ebicite|correct|EBI}}

|ChEBI = 33787

|SMILES = [BeH2]

|StdInChI_Ref = {{stdinchicite|correct|chemspider}}

|StdInChI = 1S/Be.2H

|StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

|StdInChIKey = RWASOQSEFLDYLC-UHFFFAOYSA-N

|CASNo_Ref = {{cascite|correct|CAS}}

|CASNo = 7787-52-2

|UNII_Ref = {{fdacite|correct|FDA}}

|UNII = 5M7P3TK96I

|PubChem = 139073

|ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

|ChemSpiderID=17215712

|Section2={{Chembox Properties

|Formula = BeH{{sub|2}}

|MolarMass = 11.03 g mol{{sup|−1}}

|Appearance =white solid<ref name=G&E />

|Density = 0.65 g/cm{{sup|3}}

|Solubility = decomposes

|SolubleOther = insoluble in [[diethyl ether]], [[toluene]]

|MeltingPtC = 250

|MeltingPt_notes = decomposes

}}

|Section4={{Chembox Thermochemistry

|HeatCapacity = 30.124 J/mol K

}}

|Section7={{Chembox Hazards

|REL = Ca C 0.0005 mg/m{{sup|3}} (as Be)<ref name=PGCH>{{PGCH|0054}}</ref>

|PEL = TWA 0.002 mg/m{{sup|3}}<br/>C 0.005 mg/m{{sup|3}} (30 minutes), with a maximum peak of 0.025 mg/m{{sup|3}} (as Be)<ref name=PGCH/>

|IDLH = Ca [4 mg/m{{sup|3}} (as Be)]<ref name=PGCH/>

}}

|Section8={{Chembox Related

|OtherCations = [[lithium hydride]], [[sodium hydride]], [[magnesium hydride]], [[calcium hydride]], [[borane|boron hydrides]], [[aluminium hydride]]

|OtherCompounds = [[beryllium fluoride]]

}}

}}

'''Beryllium hydride''' (systematically named '''poly[beryllane(2)]''' and '''beryllium dihydride''') is an [[inorganic compound]] with the [[chemical formula]] ({{Chem|BeH|2|}}){{sub|''n''}} (also written ({{Chem|[BeH|2|]}}){{sub|''n''}} or {{Chem|BeH|2}}). This [[alkaline earth hydride]] is a colourless solid that is insoluble in solvents that do not decompose it. Unlike the [[ionic bond|ionically bonded]] [[hydride]]s of the heavier [[alkaline earth metal|Group 2]] elements, beryllium hydride is [[covalent bond|covalently bonded]]<ref name=G&E>{{Greenwood&Earnshaw|p=115}}</ref> ([[three-center two-electron bond]]).

== Synthesis ==

Unlike the other [[alkaline earth metal|group 2]] metals, beryllium does not react with hydrogen.<ref name = "Wiberg&Holleman">Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier {{ISBN|0-12-352651-5}}, p. 1048</ref> Instead, BeH{{sub|2}} is prepared from preformed beryllium(II) compounds. It was first synthesized in 1951 by treating [[dimethylberyllium]], Be(CH{{sub|3}}){{sub|2}}, with [[lithium aluminium hydride]], LiAlH{{sub|4}}.<ref>{{cite journal |author1=Glenn D. Barbaras |author2=Clyde Dillard |author3=A. E. Finholt |author4=Thomas Wartik |author5=K. E. Wilzbach |author6=H. I. Schlesinger |name-list-style=amp | year = 1951 | title = The Preparation of the Hydrides of Zinc, Cadmium, Beryllium, Magnesium and Lithium by the Use of Lithium Aluminum Hydride | journal = [[Journal of the American Chemical Society]] | volume = 73 | issue = 10 | pages = 4585–4590 | doi = 10.1021/ja01154a025 }}</ref>

Purer BeH{{sub|2}} forms from the [[pyrolysis]] of di-tert-butylberyllium, Be(C[CH{{sub|3}}]{{sub|3}}){{sub|2}} at 210°C.<ref>{{cite journal |author1=G. E. Coates |author2=F. Glockling |name-list-style=amp | year = 1954 | title = Di-tert.-butylberyllium and beryllium hydride | journal = [[Journal of the Chemical Society]] | pages = 2526–2529 | doi = 10.1039/JR9540002526}}</ref>

A route to highly pure samples involves the reaction of [[triphenylphosphine]], PPh{{sub|3}}, with [[beryllium borohydride]], Be(BH{{sub|4}}){{sub|2}}:<ref name=G&E/>

:Be(BH{{sub|4}}){{sub|2}} + 2 PPh{{sub|3}} → BeH{{sub|2}} + 2 Ph{{sub|3}}PBH{{sub|3}}

== Structure ==

=== Gaseous form ===

[[File:Beryllium-hydride-molecule-IR-3D-balls.png|150px|thumb|left|Structure of gaseous BeH{{sub|2}}.]]

Isolated molecules of {{Chem|BeH|2}} (sometimes called dihydridoberyllium and written {{Chem|[BeH|2|]}} to emphasize the differences with the solid state) are only stable as a [[Concentration|dilute]] gas. When condensed, unsolvated {{Chem|BeH|2}} will spontaneously autopolymerise.

Free molecular BeH{{sub|2}} produced by high-temperature electrical discharge has been confirmed to have [[Linear molecular geometry|linear geometry]] with a Be-H bond length of 133.376 pm. Its hybridization is ''sp''.<ref>{{cite journal |author1=Peter F. Bernath |author2=Alireza Shayesteh |author3=Keith Tereszchuk |author4=Reginald Colin |year=2002 |title=The Vibration-Rotation Emission Spectrum of Free BeH₂ |journal=Science |volume=297 |issue=5585 |pages=1323–1324 |bibcode=2002Sci...297.1323B |doi=10.1126/science.1074580 |pmid=12193780 |s2cid=40961746}}</ref>

=== Condensed Beryllium hydride ===

BeH{{sub|2}} is usually formed as an amorphous white solid, but a [[hexagonal crystal system|hexagonal crystalline form]] with a higher density (~0.78 g/cm{{sup|3}}) was reported,<ref name="Brendel">{{cite journal |author1=G. J. Brendel |author2=E. M. Marlett |author3=L. M. Niebylski |name-list-style=amp | year = 1978 | title = Crystalline beryllium hydride | journal = [[Inorganic Chemistry (journal)|Inorganic Chemistry]] | volume = 17 | issue = 12 | pages = 3589–3592 | doi = 10.1021/ic50190a051}}</ref> prepared by heating amorphous BeH{{sub|2}} under pressure, with 0.5-2.5% [[lithium hydride|LiH]] as a catalyst.

[[File:BeH2 structure.svg|thumb|250px|Subunit of structure of BeH{{sub|2}}. Each Be is tetrahedral and each H is [[bridging ligand|doubly bridging]].<ref name="Smith" />|left]]

A more recent investigation found that crystalline beryllium hydride has a body-centred [[orthorhombic crystal system|orthorhombic]] [[unit cell]], containing a network of corner-sharing BeH{{sub|4}} tetrahedra, in contrast to the flat, hydrogen-bridged, infinite chains previously thought to exist in crystalline BeH{{sub|2}}.<ref name=Smith>{{cite journal | author = Gordon S. Smith | author2 = Quintin C. Johnson | author3 = Deane K. Smith| author4 = D. E. Cox | author5 = Robert L. Snyder | author6 = Rong-Sheng Zhou | author7 = Allan Zalkin | name-list-style = amp | year = 1988 | title = The crystal and molecular structure of beryllium hydride | journal = [[Solid State Communications]] | volume = 67 | issue = 5 | pages = 491–494 | doi = 10.1016/0038-1098(84)90168-6 | bibcode = 1988SSCom..67..491S }}</ref>

Studies of the amorphous form also find that it consists of a network of corner shared tetrahedra.<ref>{{cite journal |author1=Sujatha Sampath |author2=Kristina M. Lantzky |author3=Chris J. Benmore |author4=Jörg Neuefeind |author5=Joan E. Siewenie |name-list-style=amp | year = 2003 | title = Structural quantum isotope effects in amorphous beryllium hydride | journal = J. Chem. Phys. | volume = 119 | issue = 23| pages = 12499 | doi = 10.1063/1.1626638|bibcode=2003JChPh.11912499S }}</ref>

== Chemical properties ==

===Reaction with water and acids===

Beryllium hydride reacts slowly with water but is rapidly hydrolysed by acid such as [[hydrogen chloride]] to form [[beryllium chloride]].<ref name = "Wiberg&Holleman"/>

:BeH{{sub|2}} + 2 H{{sub|2}}O → Be(OH){{sub|2}} + 2 H{{sub|2}}

:BeH{{sub|2}} + 2 HCl → BeCl{{sub|2}} + 2 H{{sub|2}}

===Reaction with Lewis bases===

The two-coordinate hydridoberyllium group can accept an electron-pair donating [[ligand]] (L) into the molecule by adduction:<ref name="Sharp2000">{{Cite journal |last1=Sharp |first1=Stephanie B. |last2=Gellene |first2=Gregory I. |date=23 November 2000 |title=σ Bond Activation by Cooperative Interaction with ''n''s{{sup|2}} Atoms: Be + ''n'' {{Chem|H|2}}, ''n'' = 1−3 |journal=The Journal of Physical Chemistry A |volume=104 |issue=46 |pages=10951–10957 |doi=10.1021/jp002313m}}</ref>

:{{Chem|[BeH|2|]}} + L → {{Chem|[BeH|2|L]}}

Because these reactions are energetically favored, beryllium hydride has [[lewis acids and bases|Lewis-acidic]] character.

The reaction with [[lithium hydride]] (in which the hydride ion is the Lewis base), forms sequentially LiBeH{{sub|3}} and [[Lithium beryllium hydride|Li{{sub|2}}BeH{{sub|4}}]].<ref name="Wiberg&Holleman" /> The latter contains the [[tetrahydridoberyllate(2-)]] anion {{Chem|BeH|4|2-}}.

Beryllium hydride reacts with [[trimethylamine]], N(CH{{sub|3}}){{sub|3}} to form a dimeric adduct with bridging hydrides.<ref name="Shepherd1969">{{Cite journal|last=Shepherd Jr.|first=Lawrence H. |author2=Ter Haar, G. L. |author3=Marlett, Everett M.|title=Amine complexes of beryllium hydride|journal=Inorganic Chemistry|date=April 1969|volume=8|issue=4|pages=976–979|doi=10.1021/ic50074a051}}</ref> However, with [[dimethylamine]], HN(CH{{sub|3}}){{sub|2}} it forms a trimeric beryllium diamide, [Be(N(CH{{sub|3}}){{sub|2}}){{sub|2}}]{{sub|3}}, and hydrogen.<ref name="Wiberg&Holleman" />

== References ==

{{Reflist|2}}

{{Beryllium compounds}}

{{Hydrides by group}}

[[Category:Beryllium compounds]]

[[Category:Metal hydrides]]

[[Category:Substances discovered in the 1950s]]