Platinum Group Metal Compounds and Catalysts: CAS Numbers, Structures and Uses

What Counts as a Platinum Group Metal Compound#

Most platinum group metal compounds on this site are catalysts, refining precursors or coordination complexes, not the metal itself. A compound qualifies when it carries a distinct chemical identity, either a discrete molecule with its own CAS number and formula or a defined heterogeneous mixture, such as platinum on carbon, cited under one CAS number for the metal it carries.

How Each Compound Page Is Structured#

Each compound page states five fields, repeated in the tables below for direct comparison:

• CAS number
• Molecular formula
• Molecular weight
• Structure
• Primary industrial or laboratory use

Two entries, tris(bipyridine)ruthenium(II) chloride and the Noyori catalyst, carry no CAS number confirmed in PubChem as of the September 2026 audit; their table cells print "not confirmed" rather than an invented number.

Platinum Compounds and Catalysts (16)#

Platinum forms 16 compounds and catalysts covered on this site, from chloroplatinic acid, the refining intermediate behind most other platinum chemistry, to Zeise's salt, the first alkene metal complex ever isolated. Most of the sixteen are precursors that convert platinum metal into a soluble form for refining or plating; the rest are hydrosilylation and hydrogenation catalysts.

* Speier's catalyst is the same substance as chloroplatinic acid, CAS 16941-12-1; the two pages take the refining and the hydrosilylation-history angle. † Platinum on carbon lists platinum's own CAS number; the heterogeneous mixture has no single formula.

Palladium Compounds and Cross-Coupling Catalysts (16)#

Palladium forms 16 compounds and catalysts covered on this site, dominated by the cross-coupling catalysts, palladium(II) acetate, tetrakis(triphenylphosphine)palladium and XPhos Pd G3, that underpin most modern pharmaceutical synthesis. Three more, palladium on carbon, Pearlman's catalyst and the Lindlar catalyst, are heterogeneous hydrogenation catalysts cited under the CAS number for the supported metal or the commercial mixture, not a discrete molecule.

‡ These three are heterogeneous mixtures with no single molecular formula; the CAS identifies the metal or the commercial preparation.

Rhodium Compounds (6)#

Rhodium forms 6 compounds covered on this site, led by Wilkinson's catalyst, the homogeneous hydrogenation catalyst that shares rhodium's own catalytic chemistry with a laboratory rather than an automotive application. Rhodium(III) chloride's CAS number is 10049-07-7, correcting an unflagged 12648-57-6 that circulated in earlier compound data, confirmed against PubChem CID 24872.

§ Conventional formula printed; PubChem's own fragment formula is C54H45ClP3Rh-. ¶ Corrects an unflagged 12648-57-6, confirmed against PubChem CID 24872.

Iridium Compounds (6)#

Iridium forms 6 compounds covered on this site, including Crabtree's and Vaska's catalysts, two of organometallic chemistry's standard reference complexes. Iridium(IV) oxide stands apart from the other five as a PEM electrolyser catalyst, reflecting iridium's separate role in hydrogen-economy demand.

Ruthenium Compounds and Metathesis Catalysts (9)#

Ruthenium forms 9 compounds covered on this site, including the Grubbs and Hoveyda-Grubbs catalysts that carry out olefin metathesis, work recognized by the 2005 Nobel Prize in Chemistry. Grubbs catalyst carries two generation-specific CAS numbers, 172222-30-9 and 246047-72-3, so any citation needs the generation stated. Two entries below have no CAS confirmed in PubChem and are marked pending rather than invented.

‖ A second CAS, 12648-62-3, circulates but returns no PubChem record on lookup; 10049-08-8 is the sole CAS used here. # The two Grubbs generations are chemically distinct; state which one a citation refers to. ** No CAS is confirmed in PubChem for either compound.

Osmium Compounds (3)#

Osmium forms 3 compounds covered on this site, headed by osmium tetroxide, the reagent used to stain and dihydroxylate alkenes and the reason osmium metal is normally handled through a safer derivative. Osmium(IV) oxide, CAS 12036-02-1, is a distinct compound from osmium tetroxide, CAS 20816-12-0, an identity the two share only in name.

†† Distinct from osmium tetroxide, CAS 20816-12-0; earlier compound data pointed this entry at the tetroxide's own CID by mistake.

PGM Compounds in Context#

Each compound's parent element has its own properties, uses and compounds pages beyond this catalyst-and-reagent directory. The full six-element family is indexed together under platinum group metals, covering their shared position on the periodic table and catalytic chemistry.

Elements and Industrial Applications#

Platinum group metal chemistry also appears in 22 industrial application pages, covering three broad categories rather than individual compounds:

• Autocatalysts
• Fuel cells and PEM electrolysers
• Electronics

Those pages are indexed at industrial applications of platinum group metals, one level up from the compound-by-compound detail here.

Compounds FAQ#

What metals are in the platinum group?#

The platinum group metals are platinum, palladium, rhodium, iridium, ruthenium and osmium, six elements grouped for their shared catalytic and noble-metal chemistry.

What are the compounds of platinum?#

Platinum's compounds include chloroplatinic acid, the platinum(II) and platinum(IV) chlorides, Zeise's salt and several hydrosilylation catalysts, listed in full in the platinum table above.

Why isn't cisplatin listed here?#

Cisplatin and the other platinum anticancer drugs are outside this site's scope; DailyPlatinum covers PGM market, industrial and chemistry content, not medical dosing.

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