Editing Einsteinium (section)

===Halides===
[[File:Einsteinium triiodide by transmitted light.jpg|thumb|[[Einsteinium(III) iodide]] glowing in the dark]]

Einsteinium [[halide]]s are known for the oxidation states +2 and +3.<ref name="YOUNG_1981">{{cite journal|last1=Young|first1=J. P.|last2=Haire|first2=R. G.|last3=Peterson|first3=J. R.|last4=Ensor|first4=D. D.|last5=Fellow|first5=R. L.|title=Chemical consequences of radioactive decay. 2. Spectrophotometric study of the ingrowth of berkelium-249 and californium-249 into halides of einsteinium-253|journal=Inorganic Chemistry|volume=20|pages=3979–3983|date=1981|doi=10.1021/ic50225a076|issue=11}}</ref><ref name = "HOWI_1969">[[#Holleman|Holleman]], p. 1969</ref> The most stable state is +3 for all halides from fluoride to iodide.

Einsteinium(III) fluoride (EsF{{sub|3}}) can be precipitated from Es(III) chloride solutions upon reaction with [[fluoride]] ions. An alternative preparation procedure is to exposure Es(III) oxide to [[chlorine trifluoride]] (ClF{{sub|3}}) or F{{sub|2}} gas at a pressure of 1–2 atmospheres and temperature 300–400°C. The EsF{{sub|3}} crystal structure is hexagonal, as in californium(III) fluoride (CfF{{sub|3}}) where the Es{{sup|3+}} ions are 8-fold coordinated by fluorine ions in a bicapped [[Octahedral molecular geometry#Trigonal prismatic geometry|trigonal prism]] arrangement.<ref name="ES_F3">{{cite journal|last1=Ensor|first1=D. D.|last2=Peterson|first2=J. R.|last3=Haire|first3=R. G.|last4=Young|first4=J. P.|title=Absorption spectrophotometric study of {{sup|253}}EsF{{sub|3}} and its decay products in the bulk-phase solid state|journal=Journal of Inorganic and Nuclear Chemistry|volume=43|pages=2425–2427|date=1981|doi=10.1016/0022-1902(81)80274-6|issue=10}}</ref><ref name="g1270">[[#Greenwood|Greenwood]], p. 1270</ref><ref>{{cite journal|last1=Young|first1=J. P.|last2=Haire|first2=R. G.|last3=Fellows|first3=R. L.|last4=Peterson|first4=J. R.|title=Spectrophotometric studies of transcurium element halides and oxyhalides in the solid state|journal=Journal of Radioanalytical Chemistry|volume=43|pages=479–488|date=1978|doi=10.1007/BF02519508|issue=2|bibcode=1978JRNC...43..479Y |s2cid=95361392}}</ref>

Es(III) chloride (EsCl{{sub|3}}) can be prepared by annealing Es(III) oxide in the atmosphere of dry hydrogen chloride vapors at about 500°C for some 20 minutes. It crystallizes upon cooling at about 425°C into an orange solid with a [[hexagonal crystal family|hexagonal]] structure of [[uranium(III) chloride|UCl{{sub|3}} type]], where einsteinium atoms are 9-fold coordinated by chlorine atoms in a tricapped trigonal prism geometry.<ref name="m99">Miasoedov, B. F. Analytical chemistry of transplutonium elements, Wiley, 1974 (Original from the University of California), {{ISBN|0-470-62715-8}}, p. 99</ref><ref name="g1270" /><ref>{{cite journal|last1=Fujita|first1=D.|title=The solution absorption spectrum of Es<sup>3+</sup>|journal=Inorganic and Nuclear Chemistry Letters|volume=5|pages=245–250|date=1969|doi=10.1016/0020-1650(69)80192-3|issue=4|last2=Cunningham|first2=B. B.|last3=Parsons|first3=T. C.|last4=Peterson|first4=J. R.|url=http://www.escholarship.org/uc/item/3s43w87r|access-date=2019-07-14|archive-date=2020-03-09|archive-url=https://web.archive.org/web/20200309022304/https://escholarship.org/uc/item/3s43w87r|url-status=live}}</ref> [[Einsteinium(III) bromide]] (EsBr{{sub|3}}) is a pale-yellow solid with a [[monoclinic crystal system|monoclinic]] structure of [[aluminium chloride|AlCl{{sub|3}} type]], where the einsteinium atoms are [[Octahedral molecular geometry|octahedrally]] coordinated by bromine (coordination number 6).<ref name="s62" /><ref name="g1270" />

The divalent compounds of einsteinium are obtained by reducing the trivalent halides with [[hydrogen]]:<ref name="ES_II">{{cite journal|url=http://hal.archives-ouvertes.fr/docs/00/21/88/31/PDF/ajp-jphyscol197940C435.pdf|title=Preparation, characterization, and decay of einsteinium(II) in the solid state|journal=Le Journal de Physique|author=Peterson, J.R.|display-authors=etal|volume=40|issue=4|page=C4–111|date=1979|doi=10.1051/jphyscol:1979435|citeseerx=10.1.1.729.8671|s2cid=95575017 |access-date=2010-11-24|archive-date=2012-03-07|archive-url=https://web.archive.org/web/20120307233035/http://hal.archives-ouvertes.fr/docs/00/21/88/31/PDF/ajp-jphyscol197940C435.pdf|url-status=live}} [http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6593662 manuscript draft] {{Webarchive|url=https://web.archive.org/web/20130513121141/http://www.osti.gov/energycitations/product.biblio.jsp?osti_id=6593662 |date=2013-05-13 }}</ref>
:2 EsX{{sub|3}} + H{{sub|2}} → 2 EsX{{sub|2}} + 2 HX; X = F, Cl, Br, I

[[Einsteinium(II) chloride]] (EsCl{{sub|2}}),<ref>Fellows, R.L.; Young, J.P.; Haire, R.G. and Peterson J.R. (1977) in: GJ McCarthy and JJ Rhyne (eds) ''The Rare Earths in Modern Science and Technology'', Plenum Press, New York, pp. 493–499.</ref> [[einsteinium(II) bromide]] (EsBr{{sub|2}}),<ref>Young, J.P.; Haire R.G., Fellows, R.L.; Noe, M. and Peterson, J.R. (1976) "Spectroscopic and X-Ray Diffraction Studies of the Bromides of Californium-249 and Einsteinium-253", in: W. Müller and R. Lindner (eds.) ''Plutonium 1975'', North Holland, Amsterdam, pp. 227–234.</ref> and [[einsteinium(II) iodide]] (EsI{{sub|2}})<ref name = "YOUNG_1981" /> have been produced and characterized by optical absorption, with no structural information available yet.<ref name="s62" />

Known oxyhalides of einsteinium include EsOCl,<ref name="YOUNG_1981" /> EsOBr<ref name="ES_II" /> and EsOI.<ref name="YOUNG_1981" /> These salts are synthesized by treating a trihalide with a vapor mixture of water and the corresponding hydrogen halide: for example, EsCl{{sub|3}} + H{{sub|2}}O/HCl to obtain EsOCl.<ref name="s60">[[#Seaborg|Seaborg]], p. 60</ref>