Cobalt(II) nitrate

<h2 id="composition-and-structures">Composition and structures</h2>
As well as the anhydrous compound Co(NO3)2, several <a href="/facts/Hydrate/dev82l69">hydrates</a> of cobalt(II) nitrate exist. These hydrates have the <a href="/facts/Chemical_formula/hghUtthl">chemical formula</a> Co(NO3)2·nH2O, where n = 0, 2, 4, 6.
Anhydrous cobalt(II) nitrate adopts a three-dimensional polymeric network structure, with each cobalt(II) atom approximately octahedrally coordinated by six oxygen atoms, each from a different nitrate ion. Each nitrate ion coordinates to three cobalts.<a class="footnote-ref" id="fnref:2" href="#fn:2">2</a> The dihydrate is a two-dimensional polymer, with nitrate bridges between Co(II) centres and hydrogen bonding holding the layers together.<a class="footnote-ref" id="fnref:3" href="#fn:3">3</a> The tetrahydrate consists of discrete, octahedral [(H2O)4Co(NO3)2] molecules. The hexahydrate is better described as hexaaquacobalt(II) nitrate, [Co(OH2)6][NO3]2, as it consists of discrete [Co(OH2)6]2+ and [NO3]− ions.<a class="footnote-ref" id="fnref:4" href="#fn:4">4</a> Above 55 °C, the hexahydrate converts to the trihydrate and at higher temperatures to the monohydrate.<a class="footnote-ref" id="fnref:5" href="#fn:5">5</a>

<h2 id="uses-and-reactions">Uses and reactions</h2>
It is commonly reduced to metallic high purity cobalt.<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a> It can be absorbed on to various <a href="/facts/Catalyst_support/zLpv8hJB">catalyst supports</a> for use in <a href="/facts/Fischer%25E2%2580%2593Tropsch/qx8noLlC">Fischer–Tropsch</a> catalysis.<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a> It is used in the preparation of dyes and inks.<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a>
Cobalt(II) nitrate is a common starting material for the preparation of coordination complexes such as <a href="/facts/Cobaloxime/HAMrxNWn">cobaloximes</a>,<a class="footnote-ref" id="fnref:9" href="#fn:9">9</a> carbonatotetraamminecobalt(III),<a class="footnote-ref" id="fnref:10" href="#fn:10">10</a> and others.<a class="footnote-ref" id="fnref:11" href="#fn:11">11</a>

<h2 id="production">Production</h2>
The hexahydrate is prepared treating metallic cobalt or one of its oxides, hydroxides, or carbonate with <a href="/facts/Nitric_acid/UDbwGp6s">nitric acid</a>: 

Co + 4 HNO3 + 4 H2O → Co(H2O)6(NO3)2 + 2 NO2
CoO + 2 HNO3 + 5 H2O → Co(H2O)6(NO3)2
CoCO3 + 2 HNO3 + 5 H2O → Co(H2O)6(NO3)2 + CO2

<h2 id="references">References</h2>

<ol>
<li id="fn:1">John Dallas Donaldson, Detmar Beyersmann, "Cobalt and Cobalt Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a07_281.pub2 <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Tikhomirov, G. A.; Znamenkov, K. O.; Morozov, I. V.; Kemnitz, E.; Troyanov, S. I. (2002). "Anhydrous Nitrates and Nitrosonium Nitratometallates of Manganese and Cobalt, M(NO3)2, NO[Mn(NO3)3], and (NO)2[Co(NO3)4]: Synthesis and Crystal Structure". Z. anorg. allg. Chem. 628 (1): 269–273. doi:10.1002/1521-3749(200201)628:1<269::AID-ZAAC269>3.0.CO;2-P. <a href="https://doi.org/10.1002%2F1521-3749%28200201%29628%3A1%3C269%3A%3AAID-ZAAC269%3E3.0.CO%3B2-P" target="_blank">https://doi.org/10.1002%2F1521-3749%28200201%29628%3A1%3C269%3A%3AAID-ZAAC269%3E3.0.CO%3B2-P</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Ribár, B.; Milinski, N.; Herak, R.; Krstanovič, I.; Djurič, S. (1976). "The Crystal Structure of Cobalt Nitrate Dihydrate, Co(NO3)2·2H2O". Zeitschrift für Kristallographie. 144 (1–6): 133–138. Bibcode:1976ZK....144..133R. doi:10.1524/zkri.1976.144.1-6.133. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Prelesnik, P. V.; Gabela, F.; Ribar, B.; Krstanovic, I. (1973). "Hexaaquacobalt(II) nitrate". Cryst. Struct. Commun. 2 (4): 581–583. <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">John Dallas Donaldson, Detmar Beyersmann, "Cobalt and Cobalt Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a07_281.pub2 <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">John Dallas Donaldson, Detmar Beyersmann, "Cobalt and Cobalt Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005. doi:10.1002/14356007.a07_281.pub2 <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">Ernst B, Libs S, Chaumette P, Kiennemann A. Appl. Catal. A 186 (1-2): 145-168 1999 <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">Lewis, Richard J., Sr. (2002). Hawley's Condensed Chemical Dictionary (14th Edition). John Wiley & Sons. http://www.knovel.com/knovel2/Toc.jsp?BookID=704&VerticalID=0 <a href="http://www.knovel.com/knovel2/Toc.jsp?BookID=704&VerticalID=0" target="_blank">http://www.knovel.com/knovel2/Toc.jsp?BookID=704&VerticalID=0</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
<li id="fn:9">Schrauzer, G. N. (1968). Bis(Dimethylglyoximato)Cobalt Complexes: ("Cobaloximes"). Inorganic Syntheses. pp. 61–70. doi:10.1002/9780470132425.ch12. ISBN 9780470132425. <a href="9780470132425" target="_blank">9780470132425</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></li>
<li id="fn:10">Schlessinger, G. (1960). "Carbonatotetramminecobalt(III) Nitrate". Inorganic Syntheses. 6: 173–175. doi:10.1002/9780470132371.ch55. ISBN 9780470132371. {{cite journal}}: ISBN / Date incompatibility (help) <a href="9780470132371" target="_blank">9780470132371</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></li>
<li id="fn:11">Hargens, Robert D.; Min, Woonza; Henney, Robert C. (1973). "Bis(ethylenediamine)sulfito Complexes of Cobalt(III)". Inorganic Syntheses. Inorganic Syntheses. pp. 77–81. doi:10.1002/9780470132456.ch15. ISBN 9780470132456. <a href="9780470132456" target="_blank">9780470132456</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></li>
</ol>

Cobalt(II) nitrate open-in-new

Cobalt(II) nitrate