Cis-Diamminediiodoplatinum(II)
Chemical compound
From Wikipedia, the free encyclopedia
cis-Diamminediiodoplatinum(II) is a coordination complex of platinum(II) with the formula cis-[PtI2(NH3)2]. It is a red solid. Its structure has been confirmed by X-ray crystallography.[1] It is the usual precursor to a popular anticancer drug cisplatin, cis-[PtCl2(NH3)2].[2]
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| Names | |
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| IUPAC name
(SP-4-2)-Diamminediiodoplatinum(II) | |
| Other names
cis-Diiododiammineplatinum, cis-Platinumdiammine diiodide | |
| Identifiers | |
3D model (JSmol) |
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| ChemSpider | |
| ECHA InfoCard | 100.036.452 |
| EC Number |
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PubChem CID |
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| Properties | |
| H6I2N2Pt | |
| Molar mass | 482.955 g·mol−1 |
| Appearance | red-orange solid |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Synthesis
Its synthesis entails the reaction of ammonia with potassium tetraiodoplatinate, generated in situ via the reaction of potassium tetrachloroplatinate with potassium iodide:[3]
- [PtI4]2− + 2 NH3 → cis-[PtI2(NH3)2] + 2 I−
In this conversion, the addition of the second ammonia ligand is governed by the trans effect.[4][2]
A variety of related alkylamine complexes can be prepared similarly.[5][6]
Reactions
Of commercial interest, cis-[PtI2(NH3)2] reacts with aqueous silver nitrate to give the diaquo complex, which subsequently can be converted to cisplatin:[2][3]
- cis-[PtI2(NH3)2] + 2 Ag+ + 2 H2O → cis-[Pt(H2O)2(NH3)2]2+ + 2 AgI
- cis-[Pt(H2O)2(NH3)2]2+ + 2 Cl− → cis-[PtCl2(NH3)2] + 2 H2O
cis-[PtI2(NH3)2] reacts with perchloric acid to undergo deamination, giving the dimeric iodo-bridged complex:[7]
- 2 cis-[PtI2(NH3)2] + 2 HClO4 → [Pt2I4(NH3)2] + 2 NH4ClO4
This dimeric complex can then be aminated:[7]
- [Pt2I4(NH3)2] + 2 RNH2 → 2 cis-[PtI2(NH3)(H2NR)]
Oxidative addition of iodine to cis-[PtI2(NH2)2] gives the trans Pt(IV) derivative:[5]
- cis-[PtI2(NH3)2] + I2 → trans-[PtI4(NH3)2]