Curium sits near the center of the actinide series, where strong radioactivity and complex f‑electron behavior make its chemistry a specialist’s field. Studying its compounds helps researchers understand bonding, oxidation trends and how heavy elements form both simple salts and organometallic complexes.
There are 21 Curium Compounds, ranging from Curium dioxide to Tris(cyclopentadienyl)curium (Cp3Cm). For each entry you’ll find below Formula,Oxidation state,Key properties so you can quickly compare compositions, common oxidation states and notable reactivity — you’ll find below.
What oxidation states are most common in curium compounds?
Curium is most frequently encountered in the +3 oxidation state, which dominates salts and coordination complexes; +4 appears in oxides like Curium dioxide, while +2 or higher states are rare and usually require specialized ligands or controlled conditions to stabilize.
Are curium compounds stable enough for handling or applications?
Many curium compounds are chemically stable as solids, but their intense radioactivity (alpha decay and radiolysis) limits handling to licensed facilities; practical uses are mainly research, radiochemical studies and niche neutron-source roles rather than broad commercial applications.
Curium Compounds
| Name | Formula | Oxidation state | Key properties |
|---|---|---|---|
| Curium dioxide | CmO2 | +4 | Black crystalline; insoluble in water; thermally stable |
| Curium sesquioxide | Cm2O3 | +3 | Red-brown solid; insoluble; high thermal stability |
| Curium(III) fluoride | CmF3 | +3 | High-melting ionic solid; sparingly soluble in water |
| Curium(IV) fluoride | CmF4 | +4 | Yellow-green crystalline; stable under dry conditions |
| Curium(III) chloride | CmCl3 | +3 | Hygroscopic crystalline salt; water-soluble |
| Curium(III) bromide | CmBr3 | +3 | Ionic crystalline solid; water-soluble |
| Curium(III) iodide | CmI3 | +3 | Ionic solid; thermally sensitive; soluble in polar solvents |
| Curium(III) nitrate hydrate | Cm(NO3)3·nH2O | +3 | Water-soluble; common aqueous salt |
| Curium(III) sulfate | Cm2(SO4)3·nH2O | +3 | Water-soluble crystalline salt; forms hydrates |
| Curium(III) carbonate | Cm2(CO3)3·nH2O | +3 | Sparingly soluble precipitate; forms on basification |
| Curium(III) hydroxide | Cm(OH)3 | +3 | Gel-like precipitate; low water solubility |
| Curium(III) oxalate | Cm2(C2O4)3·nH2O | +3 | Insoluble precipitate; decomposes on heating to oxide |
| Curium(III) acetate | Cm(CH3COO)3·nH2O | +3 | Water-soluble coordination salt; forms hydrates |
| Curium sesquisulfide | Cm2S3 | +3 | Refractory dark solid; high melting point |
| Curium(III) aquo ion | Cm3+ (aq) | +3 | Hydrated ion; coordination number ~8–9; water-soluble |
| Curium–DTPA complex | Cm–DTPA | +3 | Stable aqueous chelate; used in decorporation studies |
| Curium–EDTA complex | Cm–EDTA | +3 | Water-soluble chelate; characterized in solution |
| Tris(cyclopentadienyl)curium (Cp3Cm) | (C5H5)3Cm | +3 | Air-sensitive organometallic; nonvolatile |
| Curium(III) perchlorate | Cm(ClO4)3·nH2O | +3 | Highly soluble; common laboratory salt |
| Curium(III) chloride hydrate | CmCl3·xH2O | +3 | Hygroscopic crystalline hydrate; water-soluble |
| Curium(III) oxalato complex (coord.) | [Cm(C2O4)(H2O)n]x | +3 | Coordination polymer/complexes; insoluble to sparingly soluble |
Images and Descriptions
Curium dioxide
Curium dioxide is the tetravalent oxide prepared by oxidizing lower oxides or metal. It is a refractory, insoluble black solid studied for solid-state chemistry; highly radioactive and handled in specialized hot cells under strict radiological controls.
Curium sesquioxide
Cm2O3 is the common trivalent oxide produced by reducing CmO2 or decomposing oxalates. It is a stable, insoluble solid used as a starting material in curium chemistry; intensely radioactive and prepared in gloveboxes or hot cells.
Curium(III) fluoride
CmF3 is a well-characterized trivalent fluoride obtained by precipitation or fluorination of Cm salts. It is chemically robust and often used in separations and materials studies; requires remote radiochemical techniques for synthesis.
Curium(IV) fluoride
CmF4 is a tetravalent curium fluoride made by oxidizing CmF3 with strong fluorinating agents. Tetravalent curium chemistry is rare; CmF4 is moisture-sensitive and handled in inert, controlled environments due to radioactivity.
Curium(III) chloride
CmCl3 is a common laboratory salt formed by acidifying and evaporating curium solutions. It is widely used to prepare other curium compounds and coordination complexes; handled remotely because of intense alpha radiation.
Curium(III) bromide
CmBr3 is obtained by halide metathesis or evaporation from bromide solutions. It behaves as a typical trivalent actinide halide and is used in synthetic chemistry under radiological controls.
Curium(III) iodide
CmI3 can be prepared by halide exchange or direct synthesis. It is useful for organometallic syntheses and is handled in inert atmospheres and shielded facilities due to radioactivity.
Curium(III) nitrate hydrate
Curium nitrate hydrates are frequently produced in nitric acid solutions and widely used in separations, chemical studies, and radiochemical preparations. Hygroscopic and radioactive, they are manipulated in hot cells and are building blocks for many syntheses.
Curium(III) sulfate
Curium sulfate salts form on treating curium solutions with sulfate. They are characterized crystallographically in small-quantity studies and are handled behind shielding because of alpha emission and radiotoxicity.
Curium(III) carbonate
Curium carbonate precipitates when curium solutions are neutralized. It is a common insoluble form used to concentrate curium and as a precursor to oxides upon thermal decomposition; prepared under radiological safety procedures.
Curium(III) hydroxide
Cm(OH)3 forms readily from base addition to curium solutions; it is colloidal to poorly crystalline and serves as a common intermediate in separation chemistry. Handling requires containment and shielding.
Curium(III) oxalate
Cm oxalate is widely used to isolate curium from solution and convert it to oxides by calcination. It is a stable solid precipitate in radiochemistry but must be handled remotely due to radioactivity.
Curium(III) acetate
Curium acetate salts are prepared by neutralizing curium nitrate with acetate. They are useful in solution chemistry and complexation studies; all manipulations are performed in shielded facilities because of radiological hazards.
Curium sesquisulfide
Cm2S3 is formed by sulfidation of oxides or direct combination at elevated temperature. It is a high-melting sulfide studied for solid-state properties; synthesis requires sealed, inert, high-temperature apparatus and radiological controls.
Curium(III) aquo ion
The Cm3+ aquo ion is the dominant species in acidic aqueous solutions. It is intensely radioactive and has been characterized spectroscopically and by thermodynamic studies; foundational to curium solution chemistry and separations.
Curium–DTPA complex
Curium complexes with DTPA (diethylenetriaminepentaacetate) are well characterized for medical decorporation research. The 1:1 chelate stabilizes Cm(III) in solution and has defined coordination behavior studied in radiochemical labs.
Curium–EDTA complex
Cm(III) forms stable complexes with EDTA, used in coordination and separation studies. These complexes alter curium mobility in aqueous systems and are studied under controlled radiochemical conditions.
Tris(cyclopentadienyl)curium (Cp3Cm)
Cp3Cm and related cyclopentadienyl curium complexes have been synthesized and characterized in specialized actinide organometallic studies. They show unique bonding features but require inert atmosphere and extensive radiological containment.
Curium(III) perchlorate
Curium perchlorates are produced by acidifying curium solutions with perchloric acid and concentrating. They are useful for crystallization and spectroscopic work; handled with strict safety due to radioactivity and oxidizing anions.
Curium(III) chloride hydrate
Specific hydrated forms of curium chloride crystallize from aqueous solutions. These hydrates are commonly reported in small-quantity solid-state characterizations and are prepared in shielded laboratories.
Curium(III) oxalato complex (coord.)
Curium forms oxalate coordination compounds used as isolation and precursor materials. These complexes are characterized crystallographically in tracer-scale experiments; preparation and study require hot cells and radiological precautions.
