Editing Platinum (section)

==Compounds==

===Halides===
Hexachloroplatinic acid mentioned above is probably the most important platinum compound, as it serves as the precursor for many other platinum compounds. By itself, it has various applications in photography, zinc etchings, [[Indelible ink#Indelible ink|indelible ink]], plating, mirrors, porcelain coloring, and as a catalyst.<ref name="krebs">{{cite book|title = The History and Use of our Earth's Chemical Elements|author = Krebs, Robert E.|chapter = Platinum|pages = [https://archive.org/details/historyuseofoure00kreb/page/124 124–127]|publisher = Greenwood Press|date = 1998|isbn = 978-0-313-30123-0|chapter-url = https://archive.org/details/historyuseofoure00kreb/page/124}}</ref>

Treatment of hexachloroplatinic acid with an ammonium salt, such as [[ammonium chloride]], gives [[ammonium hexachloroplatinate]],<ref name="Kauuf">{{Cite book|first1 = George B.|last1 = Kauffman|author-link = George B. Kauffman |date = 1967|volume = 9 |pages = 182–185|doi = 10.1002/9780470132401.ch51|last2 = Thurner|first2 = Joseph J.|last3 = Zatko|first3 = David A.| title=Inorganic Syntheses | chapter=Ammonium Hexachloroplatinate(IV) |isbn = 978-0-470-13240-1}}</ref> which is relatively insoluble in ammonium solutions. Heating this ammonium salt in the presence of hydrogen reduces it to elemental platinum.<!--Platinum is often isolated from ores and recycled thus.<ref>Cotton, S. A. [https://books.google.com/books?id=6VKAs6iLmwcC&pg=PA78 Chemistry of Precious Metals], Chapman and Hall (London): 1997. {{ISBN|0-7514-0413-6}}.</ref> Neither the text nor reference fit here--> [[Potassium hexachloroplatinate]] is similarly insoluble, and hexachloroplatinic acid has been used in the determination of potassium ions by [[gravimetry]].<ref>{{cite journal|first1 = G. F.|last1 =Smith |first2=J. L.|last2 = Gring|title = The Separation and Determination of the Alkali Metals Using Perchloric Acid. V. Perchloric Acid and Chloroplatinic Acid in the Determination of Small Amounts of Potassium in the Presence of Large Amounts of Sodium|journal = [[Journal of the American Chemical Society]]|date = 1933|volume = 55|issue = 10|pages = 3957–3961|doi = 10.1021/ja01337a007|bibcode =1933JAChS..55.3957S }}</ref>

When hexachloroplatinic acid is heated, it decomposes through [[platinum(IV) chloride]] and [[platinum(II) chloride]] to elemental platinum, although the reactions do not occur stepwise:<ref>{{cite journal|first1 = A. E.|last1 =Schweizer|first2 = G. T.|last2 =Kerr|title = Thermal Decomposition of Hexachloroplatinic Acid|journal = [[Inorganic Chemistry (journal)|Inorganic Chemistry]]|date = 1978|volume = 17|issue = 8|pages = 2326–2327|doi = 10.1021/ic50186a067}}</ref>

: {{chem2|(H3O)2PtCl6*''n''H2O <-> PtCl4 + 2 HCl + (''n'' + 2) H2O}}
: {{chem2|PtCl4 <-> PtCl2 + Cl2}}
: {{chem2|PtCl2 <-> Pt + Cl2}}

All three reactions are reversible. [[Platinum(II) bromide|Platinum(II)]] and [[platinum(IV) bromide]]s are known as well. [[Platinum hexafluoride]] is a strong oxidizer capable of [[dioxygenyl#Synthesis|oxidizing oxygen]].

===Oxides===
[[Platinum(IV) oxide]], {{chem2|PtO2}}, also known as "[[Adams' catalyst]]", is a black powder that is soluble in [[potassium hydroxide]] (KOH) solutions and concentrated acids.<ref name="perry">{{Cite book |title = Handbook of Inorganic Compounds |series=Nature |volume=177 |last=Perry |first=D. L. |pages = 296–298|date = 1995|issue=4510 |isbn = 978-0-8493-8671-8|bibcode=1956Natur.177..639.|doi=10.1038/177639a0|s2cid=4184615}}</ref> {{chem2|PtO2}} and the less common {{chem2|PtO}} both decompose upon heating.<ref name="lagowski" /> Platinum(II,IV) oxide, {{chem2|Pt3O4}}, is formed in the following reaction:

:{{chem2|2 Pt(2+) + Pt(4+) + 4 O(2−) → Pt3O4}}

===Other compounds===
Unlike [[palladium acetate]], [[platinum(II) acetate]] is not commercially available. Where a base is desired, the halides have been used in conjunction with [[sodium acetate]].<ref name = han/> The use of platinum(II) acetylacetonate has also been reported.<ref>{{cite journal|first1 = Sebastian |last1= Ahrens |first2= Thomas|last2= Strassner|doi = 10.1016/j.ica.2006.05.042|title = Detour-free synthesis of platinum-bis-NHC chloride complexes, their structure and catalytic activity in the CH activation of methane|date = 2006|journal = Inorganica Chimica Acta|volume = 359|pages = 4789–4796|issue = 15}}</ref>

Platinum exhibits negative oxidation states at surfaces reduced electrochemically,<ref>{{cite journal|doi=10.1021/jp068879d|title=Spectroscopic Evidence of Platinum Negative Oxidation States at Electrochemically Reduced Surfaces|date=2007|display-authors=4|last1=Ghilane|first1=J.|last2=Lagrost|first2=C.|last3=Guilloux-Viry|first3=M.|last4=Simonet|first4=J.|last5=Delamar|first5=M.|last6=Mangeney|first6=C.|last7=Hapiot|first7=P.|journal=Journal of Physical Chemistry C|volume=111|pages=5701–7|issue=15}}</ref> and several "platinides" have been synthesized in which platinum exhibits oxidation states ranging from −1 to −2.  The negative oxidation states exhibited by platinum are unusual for metallic elements, and they are attributed to the relativistic stabilization of the 6s orbitals.<ref name="Jansen" /> Barium platinides include BaPt, {{chem|Ba|3|Pt|2}}, and {{chem|Ba|2|Pt}}.<ref>{{cite journal| doi = 10.1039/b514631c |title = An experimental proof for negative oxidation states of platinum: ESCA-measurements on barium platinides|first1=Andrey |last1= Karpov| first2=Mitsuharu| pmid = 16479284 |last2=Konuma|first3=Martin |last3=Jansen|journal = Chemical Communications|volume = 44|date = 2006| issue = 8|pages = 838–840}}</ref> Caesium platinide, {{chem|Cs|2|Pt}}, a dark-red transparent crystalline compound<ref>{{cite journal|doi=10.1002/anie.200352314|title=Cs2Pt: A Platinide(-II) Exhibiting Complete Charge Separation|date=2003|last1=Karpov|first1=Andrey|last2=Nuss|first2=Jürgen|last3=Wedig|first3=Ulrich|last4=Jansen|first4=Martin|journal=Angewandte Chemie International Edition|volume=42|issue=39|pages=4818–21|pmid=14562358}}</ref> has been shown to contain Pt{{su|p=2−}} anions.<ref name="Jansen">{{cite journal|doi=10.1016/j.solidstatesciences.2005.06.015|title=Effects of relativistic motion of electrons on the chemistry of gold and platinum|date=2005|last1=Jansen|first1=Martin|journal=Solid State Sciences|volume=7|pages=1464–74|bibcode=2005SSSci...7.1464J|issue=12|doi-access=free}}</ref> The "platinum [[Grignard reagent|Grignard]]" Pt(MgCl)<sub>2</sub>&middot;{{mvar|n}}[[tetrahydrofuran|THF]] conjecturally contains Pt<sup>2&minus;</sup> as well.<ref>{{Cite journal |last=Ellis |first=John E. |date=2006-04-17 |title=Adventures with Substances Containing Metals in Negative Oxidation States |url=https://pubs.acs.org/doi/10.1021/ic052110i |journal=Inorganic Chemistry |language=en |volume=45 |issue=8 |page=3170 |doi=10.1021/ic052110i |issn=0020-1669}}</ref>  

It is predicted that even the cation {{chem|PtO|4|2+}} in which platinum exists in the +10 oxidation state may be achievable.<ref>{{cite web |first=M. |last=Gunther |title=Oxidation state +10 may exist in a platinum compound |date=13 June 2016 |publisher=Chemistry World |url=https://www.chemistryworld.com/news/oxidation-state-10-may-exist-in-a-platinum-compound/1010184.article}}<br/>{{cite journal |first1=H.S. |last1=Yu |first2=D.G. |last2=Truhlar |title=Oxidation State 10 Exists |journal=Angew. Chem. Int. Ed. |volume=55 |issue= 31|pages=9004–6 |date=2016 |doi=10.1002/anie.201604670 |pmid=27273799 |url=|doi-access=free }}</ref>

[[Zeise's salt]], containing an [[ethylene]] ligand, was one of the first [[organometallic compound]]s discovered. {{chem name|[[Dichloro(cycloocta-1,5-diene)platinum(II)]]}} is a commercially available [[Alkene|olefin]] complex, which contains easily displaceable [[1,5-Cyclooctadiene|cod ligands]] ("cod" being an abbreviation of 1,5-cyclooctadiene). The cod complex and the halides are convenient starting points to platinum chemistry.<ref name="han" />

[[Cisplatin]], or {{chem name|''cis''-diamminedichloroplatinum(II)}} is the first of a series of square planar platinum(II)-containing chemotherapy drugs.<ref>{{cite book|last1=Riddell|first1=Imogen A.|last2=Lippard|first2=Stephen J.
|editor1-last=Sigel|editor1-first=Astrid|editor2-last=Sigel|editor2-first=Helmut|editor3-last=Freisinger|editor3-first=Eva|editor4-last=Sigel|editor4-first=Roland K. O.
|title=Metallo-Drugs:Development and Action of Anticancer Agents
|series=Metal Ions in Life Sciences|volume=18|date=2018
|isbn=978-3-11-046984-4
|doi=10.1515/9783110470734-007
|pmid=29394020|pages=1–42|chapter=Cisplatin and Oxaliplatin:Our Current Understanding of Their Actions}}</ref> Others include [[carboplatin]] and [[oxaliplatin]]. These compounds are capable of [[cross-link|crosslinking]] [[DNA]], and kill cells by similar pathways to alkylating [[chemotherapy|chemotherapeutic agents]].<ref name="Richards">{{cite journal|last1 = Richards|first1 = A. D.|last2 = Rodger|first2 = A.|date = 2007|title = Synthetic metallomolecules as agents for the control of DNA structure|journal = Chemical Society Reviews|volume = 36|pages = 471–483|doi = 10.1039/b609495c|pmid = 17325786|issue = 3|df = dmy-all|url = http://wrap.warwick.ac.uk/2189/1/WRAP_Richards_Revised_article1.pdf}}</ref> (Side effects of cisplatin include nausea and vomiting, hair loss, tinnitus, hearing loss, and nephrotoxicity.)<ref name="M.D.R.Ph.2014">{{cite book|last1=Carinder|first1=James A.|last2=Morrison|first2=Pilar M.|last3=Morrison|first3=David G.|author4=Jack E. Saux III|title=Practical Oncology Protocols|url=https://books.google.com/books?id=rxPaAwAAQBAJ&pg=PA22|access-date=11 June 2016|date=7 July 2014|publisher=Mill City Press, Incorporated|isbn=978-1-62652-816-1|page=22|url-status=live|archive-url=https://web.archive.org/web/20171109202329/https://books.google.com/books?id=rxPaAwAAQBAJ&pg=PA22|archive-date=9 November 2017|df=dmy-all}}</ref><ref name="TaguchiNazneen2005">{{Cite book|last1=Taguchi|first1=Takashi|last2=Nazneen|first2=Arifa|last3=Abid|first3=M. Ruhul|last4=Razzaque|first4=Mohammed S.|title=Cisplatin-Associated Nephrotoxicity and Pathological Events|year=2005|pages=107–121|doi=10.1159/000086055|pmid=15912030|volume=148|series=Contributions to Nephrology|isbn=978-3-8055-7858-5|s2cid=24509477}}</ref>

[[Organoplatinum]] compounds such as the above antitumour agents, as well as soluble inorganic platinum complexes, are routinely characterised using [[Platinum-195 nuclear magnetic resonance|{{chem|195|Pt}} nuclear magnetic resonance spectroscopy]].

<gallery widths="160px" heights="140px">
File:Hexachloridoplatinat-Ion.svg|The hexachloroplatinate ion
File:Zeise's-salt-anion-3D-balls.png|The anion of Zeise's salt
File:Dichloro(cycloocta-1,5-diene)platinum(II)-from-xtal-3D-balls-E.png|{{chem name|Dichloro(cycloocta-1,5-diene)platinum(II)}}
File:Cisplatin-3D-balls.png|Cisplatin</gallery>