| Atomic Mass | 195.084 |
|---|---|
| Electron Configuration | [Xe]6s14f145d9 |
| Oxidation States | +4, +2 |
| Year Discovered | 1735 |
| Atomic Mass | 195.084 |
|---|---|
| Electron Configuration | [Xe]6s14f145d9 |
| Oxidation States | +4, +2 |
| Year Discovered | 1735 |
| Element Name | Platinum |
|---|---|
| Element Symbol | Pt |
| InChI | InChI=1S/Pt |
| InChIKey | BASFCYQUMIYNBI-UHFFFAOYSA-N |
| Atomic Weight |
195.084(9) 195.084 195.1 195.084(9) |
|---|---|
| Electron Configuration |
[Xe]6s14f145d9 |
| Atomic Radius |
Van der Waals Atomic Radius : 209 pm (Van der Waals) Empirical Atomic Radius : 135pm (Empirical) Covalent Atomic Radius : 136(5) pm (Covalent) |
| Oxidation States |
+4, +2 6, 5, 4, 3, 2, 1, -1, -2, -3 (a mildly basic oxide) |
| Ground Level |
3D3 |
| Ionization Energy |
9 eV 8.95883 ± 0.00010 eV |
| Electronegativity |
Pauling Scale Electronegativity : 2.28(Pauling Scale) Allen Scale Electronegativity : 1.72(Allen Scale) |
| Electron Affinity |
2.128eV 2.56eV |
| Atomic Spectra |
Lines Holdings Levels Holdings |
| Physical Description |
Solid |
| Element Classification |
Metal |
| Element Period Number |
6 |
| Element Group Number |
10 |
| Density |
21.46 grams per cubic centimeter |
| Melting Point |
2041.55 K (1768.4°C or 3215.1°F) 1768.3°C |
| Boiling Point |
4098 K (3825°C or 6917°F) 3825°C |
| Estimated Crustal Abundance |
5×10-3 milligrams per kilogram |
| Estimated Oceanic Abundance |
Not Applicable |
The name derives from the Spanish platina for "silver". In 1735, the Spanish astronomer Antonio de Ulloa found platinum in Peru, South America. In 1741, the English metallurgist Charles Wood found platinum from Colombia, South America. In 1750, the English physician William Brownrigg prepared purified platinum metal.
Used by the pre-Columbian Indians of South America, platinum wasn't noticed by western scientists until 1735. Platinum can occur free in nature and is sometimes found in deposits of gold-bearing sands, primarily those found in the Ural mountains, Columbia and the western United States. Platinum, in the form of the mineral sperrylite (PtAs2), is also obtained as a byproduct of the nickel mining operation in the Sudbury region of Ontario, Canada. Credit for the modern rediscovery of platinum is usually given to Antonio de Ulloa.
Discovered in South America by Ulloa in 1735 and by Wood in 1741. The metal was used by pre-Columbian Indians.
| Year | Atomic Weight (uncertainty) [u] | Reference |
|---|---|---|
| 2005 | 195.084(9) | https://doi.org/10.1351/pac200678112051 |
| 1995 | 195.078(2) | https://doi.org/10.1351/pac199668122339 |
| 1979 | 195.08(3) | https://doi.org/10.1351/pac198052102349 |
| 1969 | 195.09(3) | https://doi.org/10.1351/pac197021010091 |
| 1955 | 195.09 | https://doi.org/10.1021/ja01595a001 |
| 1925 | 195.23 | https://doi.org/10.1039/CT9252700913 |
| 1911 | 195.2 | https://doi.org/10.1021/ja01928a001 |
| 1909 | 195.0 | https://doi.org/10.1021/ja01931a001 |
| 1902 | 194.8 | https://doi.org/10.1007/BF01370337 |
Platinum is a beautiful silvery-white metal, when pure, and is malleable and ductile. It has a coefficient of expansion almost equal to that of soda-lime-silica glass, and is therefore used to make sealed electrodes in glass systems. The metal does not oxidize in air at any temperature, but is corroded by halogens, cyanides, sulfur, and caustic alkalis.
It is insoluble in hydrochloric and nitric acid, but dissolves when they are mixed as aqua regia, forming chloroplatinic acid.
Platinum is a soft, dense, ductile metal that is very resistant to corrosion. It is used to make jewelry, wire, electrical contacts and laboratory vessels. Platinum expands at nearly the same rate as soda-lime-silica glass, so it is used to make sealed electrodes in glass systems. Platinum is used to coat missile nose cones, jet engine fuel nozzles and other devices that must operate reliably for long periods of time at high temperatures. Platinum resistance wires are used in high temperature electric furnaces. Platinum anodes are used in cathodic protection systems to prevent ships, pipelines and steel piers from corroding in salt water.
Platinum is widely used as a catalyst. It will convert methyl alcohol vapors (CH4O) into formaldehyde (CH2O) on contact, glowing red hot in the process. This effect is used to make small hand warmers. Platinum is also used in a device called a catalytic converter, a device found in the exhaust systems of most cars. Catalytic converters combine carbon monoxide (CO) and unburned fuel from a car's exhaust with oxygen from the air, forming carbon dioxide (CO2) and water vapor (H2O). Platinum is also used as a catalyst in the production of sulfuric acid (H2SO4) and in the cracking of petroleum products. Fuel cells, devices that combine hydrogen and oxygen to produce electricity and water, also use platinum as a catalyst.
The metal is extensively used in jewelry, wire, and vessels for laboratory use, and in many valuable instruments including therocouple elements. It is also used for electrical contacts, corrosion-resistant apparatus, and in dentistry.
Platinum-cobalt alloys have magnetic properties. One such alloy made of 76.7% Pt and 23.3% Co, by weight, is an extremely powerful magnet that offers a B-H (max) almost twice that of Alnico V. Platinum resistance wires are used for constructing high-temperature electric furnaces.
The metal is used for coating missile nose cones, jet engine fuel nozzles, etc., which must perform reliably at high temperatures for long periods of time. The metal, like palladium, absorbs large volumes of hydrogen, retaining it at ordinary temperatures but giving it up when heated.
In the finely divided state platinum is an excellent catalyst, having long been used in the contact process for producing sulfuric acid. It is also used as a catalyst in cracking petroleum products. Much interest exists in using platinum as a catalyst in fuel cells and in antipollution devices for automobiles.
Platinum anodes are extensively used in cathodic protection systems for large ships and ocean-going vessels, pipelines, steel piers, etc. Fine platinum wire will glow red hot when placed in the vapor of methyl alcohol. It acts here as a catalyst, converting the alcohol to formaldehyde. The phenomenon has been used commercially to produce cigarette lighters and hand warmers. Hydrogen and oxygen explode in the presence of platinum.
Platinum occurs natively, accompanied by small quantities of iridium, osmium, palladium, ruthenium, and rhodium, all belonging to the same group of metals. These are found in the alluvial deposits of the Ural mountains, of Columbia, and of certain western American states. Sperrylite, occurring with the nickel-bearing deposits of Sudbury, Ontario, is the source of a considerable amount of metal.
The large production of nickel makes up for the fact that is only one part of the platinum metals in two million parts of ore.
See more information at the Platinum compound page.
| CID | Name | Formula | SMILES | Molecular Weight |
|---|---|---|---|---|
| 23939 | platinum | Pt | [Pt] | 195.08 |
| 105166 | platinum(2+) | Pt+2 | [Pt+2] | 195.08 |
| 105160 | platinum(4+) | Pt+4 | [Pt+4] | 195.08 |
| 161142 | platinum-191 | Pt | [191Pt] | 190.96168 |
| 167028 | platinum-195 | Pt | [195Pt] | 194.964794 |
| 167343 | platinum-199 | Pt | [199Pt] | 198.97060 |
| 167351 | platinum-193 | Pt | [193Pt] | 192.96298 |
| 177513 | platinum-188 | Pt | [188Pt] | 187.95940 |
| 177537 | platinum-186 | Pt | [186Pt] | 185.9594 |
| 177652 | platinum-197 | Pt | [197Pt] | 196.967343 |
| 185697 | platinum-200 | Pt | [200Pt] | 199.9714 |
| 177550 | platinum-189 | Pt | [189Pt] | 188.9608 |
| 46898737 | platinum-195(4+) | Pt+4 | [195Pt+4] | 194.964794 |
| Stable Isotope Count | 5 |
|---|
Astrophysicists have confirmed an anomaly in the isotopic composition of platinum in the chemically peculiar HgMn star χ Lupi, where the platinum isotopic composition was shown to be a mixture of 196Pt and 198Pt (Fig. IUPAC.78.1) [526].
![Fig. IUPAC.78.1: Observed spectra of the chemically peculiar HgMn star χ Lupi (solid blue line) compared to a synthetic spectra calculated with a mixture of 70 percent ¹⁹⁶Pt and 30 percent ¹⁹⁸Pt (dotted pink line) (modified after [526]).](https://pubchem.ncbi.nlm.nih.gov/images/iupac/j_pac-2015-0703_fig_106.jpg)
The decay of 190Pt (with a half-life of 4.9×1011 years) to 186Os over time has been used for dating rocks and iron meteorites [527].
195mPt (with a half-life of 4 days) is used for pharmacokinetic studies of platinum-based anti-tumor agents in cancer diagnosis and cancer therapy [188]. The m in the superscript of 195mPt indicates a metastable state of the isotope. 195mPt can be produced from the stable isotopes 192Os or 195Pt via the 192Os (α, n) 195mPt reaction and the 195Pt (n, n′) 195mPt reaction, respectively.
| Isotope | Atomic Mass (uncertainty) [u] | Abundance (uncertainty) | |
|---|---|---|---|
| 190Pt | 189.959 950(5) | 0.000 12(2) | 0.00012(2) |
| 192Pt | 191.961 04(2) | 0.007 82(24) | 0.00782(24) |
| 194Pt | 193.962 683(3) | 0.328 64(410) | 0.3286(40) |
| 195Pt | 194.964 794(3) | 0.337 75(240) | 0.3378(24) |
| 196Pt | 195.964 955(3) | 0.252 11(340) | 0.2521(34) |
| 198Pt | 197.967 90(2) | 0.073 56(130) | 0.07356(130) |
| Nuclide | Atomic Mass and Uncertainty [u] | Half Life and Uncertainty | Discovery Year | Decay Modes, Intensities and Uncertainties [%] |
|---|---|---|---|---|
| 165Pt | 164.999658 ± 0.000429 [Estimated] | 370 us ± 180 | 2019 | α=100% |
| 166Pt | 165.994866 ± 0.000322 [Estimated] | 294 us ± 62 | 1996 | α=100% |
| 167Pt | 166.992750 ± 0.000329 [Estimated] | 915 us ± 123 | 1996 | α=100% |
| 168Pt | 167.988180196 ± 0.00016096 | 2.02 ms ± 0.10 | 1981 | α≈100%; β+ ? |
| 169Pt | 168.986619 ± 0.000215 [Estimated] | 6.99 ms ± 0.09 | 1981 | α≈100%; β+ ? |
| 170Pt | 169.982502087 ± 0.000019588 | 13.93 ms ± 0.16 | 1981 | α≈100%; β+ ? |
| 171Pt | 170.981248868 ± 0.000086904 | 45.5 ms ± 2.5 | 1981 | α=86±0.3%; β+ ? |
| 171Ptm | 170.981248868 ± 0.000086904 | 901 ns ± 9 | 2010 | IT=100% |
| 172Pt | 171.977341059 ± 0.000011139 | 97.6 ms ± 1.3 | 1981 | α=96±0.3%; β+ ? |
| 173Pt | 172.976449922 ± 0.000068096 | 382 ms ± 2 | 1966 | α=86±0.4%; β+ ? |
| 174Pt | 173.972820431 ± 0.000011098 | 862 ms ± 8 | 1966 | α=74.9±2.4%; β+ ? |
| 175Pt | 174.972400593 ± 0.000019982 | 2.43 s ± 0.04 | 1966 | α=64±0.5%; β+ ? |
| 176Pt | 175.968938162 ± 0.000013647 | 6.33 s ± 0.15 | 1966 | β+ ?; α=40±0.2% |
| 177Pt | 176.968469541 ± 0.00001609 | 10.0 s ± 0.4 | 1966 | β+=94.3±0.5%; α=5.7±0.5% |
| 177Ptm | 176.968469541 ± 0.00001609 | 2.35 us ± 0.04 | 1979 | IT=100% |
| 178Pt | 177.965649288 ± 0.000010878 | 20.7 s ± 0.7 | 1966 | β+=92.3±0.3%; α=7.7±0.3% |
| 179Pt | 178.965358742 ± 0.000008563 | 21.2 s ± 0.4 | 1966 | β+≈100%; α=0.24±0.3% |
| 180Pt | 179.963038010 ± 0.00001079 | 56 s ± 3 | 1966 | β+=99.48±0.5%; α=0.52±0.5% |
| 181Pt | 180.963089946 ± 0.000014695 | 52.0 s ± 2.2 | 1966 | β+≈100%; α=0.074±1% |
| 181Ptm | 180.963089946 ± 0.000014695 | >300 ns | 1992 | IT=100% |
| 182Pt | 181.961171605 ± 0.000014057 | 2.67 m ± 0.12 | 1963 | β+=0.962±0.2%; α=0.038±0.2% |
| 183Pt | 182.961595895 ± 0.000015261 | 6.5 m ± 1.0 | 1963 | β+≈100%; α=0.0096±0.5% |
| 183Ptm | 182.961595895 ± 0.000015261 | 43 s ± 5 | 1979 | β+=96.9±0.8%; IT=3.1±0.8%; α ? |
| 183Ptn | 182.961595895 ± 0.000015261 | >150 ns | 1990 | IT=100% |
| 184Pt | 183.959921929 ± 0.000015828 | 17.3 m ± 0.2 | 1963 | β+≈100%; α=0.0017±0.7% |
| 184Ptm | 183.959921929 ± 0.000015828 | 1.01 ms ± 0.05 | 1966 | IT=100% |
| 185Pt | 184.960613659 ± 0.000027731 | 70.9 m ± 2.4 | 1960 | β+≈100%; α=0.0050±2% |
| 185Ptm | 184.960613659 ± 0.000027731 | 33.0 m ± 0.8 | 1970 | β+≈100%; IT ? |
| 185Ptn | 184.960613659 ± 0.000027731 | 728 ns ± 20 | 1996 | IT=100% |
| 186Pt | 185.959350845 ± 0.000023344 | 2.08 h ± 0.05 | 1961 | β+=100%; α≈1.4e-4% |
| 187Pt | 186.960616646 ± 0.000025837 | 2.35 h ± 0.03 | 1961 | β+=100% |
| 187Ptm | 186.960616646 ± 0.000025837 | 311 us ± 15 | 1976 | IT=100% |
| 188Pt | 187.959397521 ± 0.000005694 | 10.16 d ± 0.18 | 1954 | ε=100%; α=2.6e-5±0.3% |
| 189Pt | 188.960848485 ± 0.000010832 | 10.87 h ± 0.12 | 1955 | β+=100% |
| 189Ptm | 188.960848485 ± 0.000010832 | 464 ns ± 25 | 1970 | IT=100% |
| 189Ptn | 188.960848485 ± 0.000010832 | 143 us ± 5 | 1976 | IT=100% |
| 190Pt | 189.959949823 ± 0.000000705 | 483 Gy ± 3 | 1949 | IS=0.012±0.2%; α=100%; 2β+ ? |
| 191Pt | 190.961676261 ± 0.00000443 | 2.83 d ± 0.02 | 1948 | ε=100% |
| 191Ptm | 190.961676261 ± 0.00000443 | >1 us | 1976 | IT=100% |
| 191Ptn | 190.961676261 ± 0.00000443 | 95 us ± 5 | 1967 | IT=100% |
| 192Pt | 191.961042667 ± 0.000002758 | Stable >60Py | 1935 | IS=0.782±2.4%; α ? |
| 192Ptm | 191.961042667 ± 0.000002758 | 272 ns ± 23 | 1976 | IT=100% |
| 193Pt | 192.962984546 ± 0.000001458 | 50 y ± 6 | 1948 | ε=100% |
| 193Ptm | 192.962984546 ± 0.000001458 | 4.33 d ± 0.03 | 1949 | IT=100% |
| 194Pt | 193.962683498 ± 0.000000532 | Stable | 1935 | IS=32.864±41% |
| 195Pt | 194.964794325 ± 0.00000054 | Stable >6.3Ey | 1935 | IS=33.775±24%; α ? |
| 195Ptm | 194.964794325 ± 0.00000054 | 4.010 d ± 0.005 | 1960 | IT=100% |
| 196Pt | 195.964954648 ± 0.000000547 | Stable | 1935 | IS=25.211±34% |
| 197Pt | 196.967343030 ± 0.000000575 | 19.8915 h ± 0.0019 | 1936 | β-=100% |
| 197Ptm | 196.967343030 ± 0.000000575 | 95.41 m ± 0.18 | 1941 | IT=96.7±0.4%; β-=3.3±0.4% |
| 198Pt | 197.967896718 ± 0.000002254 | Stable | 1935 | IS=7.356±13%; 2β- ?; α ? |
| 199Pt | 198.970597022 ± 0.000002317 | 30.80 m ± 0.21 | 1937 | β-=100% |
| 199Ptm | 198.970597022 ± 0.000002317 | 13.48 s ± 0.16 | 1959 | IT=100% |
| 200Pt | 199.971444609 ± 0.000021588 | 12.6 h ± 0.3 | 1957 | β-=100% |
| 201Pt | 200.974513305 ± 0.000053788 | 2.5 m ± 0.1 | 1962 | β-=100% |
| 201Ptm | 200.974513305 ± 0.000053788 | 10 s [Estimated] | IT ? | |
| 202Pt | 201.975639000 ± 0.000027 | 44 h ± 15 | 1992 | β-=100% |
| 202Ptm | 201.975639000 ± 0.000027 | 141 us ± 7 | 2005 | IT=100% |
| 203Pt | 202.979055 ± 0.000215 [Estimated] | 22 s ± 4 | 2008 | β-=100% |
| 203Ptm | 202.979055 ± 0.000215 [Estimated] | 12 s ± 5 | 2008 | β-≈100%; IT ? |
| 203Ptn | 202.979055 ± 0.000215 [Estimated] | >100 ns [Estimated] | 2008 | IT=100% |
| 203Ptp | 202.979055 ± 0.000215 [Estimated] | 641 ns ± 55 | 2011 | IT=100% |
| 204Pt | 203.981084 ± 0.000215 [Estimated] | 10.3 s ± 1.4 | 2008 | β-=100% |
| 204Ptm | 203.981084 ± 0.000215 [Estimated] | 5.5 us ± 0.7 | 2009 | IT=100% |
| 204Ptn | 203.981084 ± 0.000215 [Estimated] | 55 us ± 3 | 2009 | IT=100% |
| 204Ptp | 203.981084 ± 0.000215 [Estimated] | 146 ns ± 14 | 2009 | IT=100% |
| 205Pt | 204.986237 ± 0.000322 [Estimated] | 2 s >300ns [Estimated] | 2009 | β- ? |
| 206Pt | 205.990080 ± 0.000322 [Estimated] | 500 ms >300ns [Estimated] | 2012 | β- ?; β-n ? |
| 207Pt | 206.995556 ± 0.000429 [Estimated] | 600 ms >300ns [Estimated] | 2012 | β- ?; β-n ? |
| 208Pt | 207.999463 ± 0.000429 [Estimated] | 220 ms >300ns [Estimated] | 2012 | β- ?; β-n ? |
