_chloride_hexahydrate.jpg) | |
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| Names | |
|---|---|
| IUPAC name samarium(III) chloride | |
| Other names samarium trichloride trichlorosamarium | |
| Identifiers | |
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3D model (JSmol) | |
| ChemSpider |
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| ECHA InfoCard | 100.030.712 |
| EC Number |
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| UNII |
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| Properties | |
| SmCl3 | |
| Molar mass | 256.76 g/mol (anhydrous) 364.80 g/mol (hexahydrate) |
| Appearance | pale yellow solid (anhydrous) cream-coloured solid (hexahydrate) |
| Density | 4.46g/cm3 (anhydrous) 2.383g/cm3 (hexahydrate) |
| Melting point | 682 °C (1,260 °F; 955 K) |
| Boiling point | decomposes |
| 92.4g/100mL (10 °C) | |
| Structure | |
| hexagonal,hP8 | |
| P63/m, No. 176 | |
| Tricapped trigonal prismatic (nine-coordinate) | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards | Irritant |
| GHS labelling: | |
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| Warning | |
| H315,H319 | |
| P264,P280,P302+P352,P305+P351+P338,P321,P332+P313,P337+P313,P362 | |
| Related compounds | |
Otheranions | Samarium(III) fluoride Samarium(III) bromide Samarium(III) oxide |
Othercations | Samarium(II) chloride Promethium(III) chloride Europium(III) chloride |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Samarium(III) chloride, also known as samarium trichloride, is aninorganic compound ofsamarium andchloride. It is a pale yellow salt that rapidly absorbs water to form a hexahydrate, SmCl3.6H2O.[1] The compound has few practical applications but is used in laboratories for research on new compounds of samarium.
Like several related chlorides of the lanthanides and actinides, SmCl3 crystallises in the UCl3 motif. The Sm3+ centres are nine-coordinate, occupying trigonal prismatic sites with additional chloride ligands occupying the three square faces.
SmCl3 is prepared by the "ammonium chloride" route, which involves the initial synthesis of (NH4)2[SmCl5]. This material can be prepared from the common starting materials at reaction temperatures of 230 °C fromsamarium oxide:[2]
The pentachloride is then heated to 350-400 °C resulting in evolution of ammonium chloride and leaving a residue of the anhydrous trichloride:
It can also be prepared fromsamarium metal andhydrochloric acid.[3][4]
Aqueous solutions of samarium(III) chloride can be prepared by dissolving metallicsamarium or samarium carbonate inhydrochloric acid.
Samarium(III) chloride is a moderately strongLewis acid, which ranks as "hard" according to theHSAB concept. Aqueous solutions of samarium chloride can be used to preparesamarium trifluoride:
Samarium(III) chloride is used for the preparation ofsamarium metal, which has a variety of uses, notably inmagnets. Anhydrous SmCl3 is mixed withsodium chloride orcalcium chloride to give a lowmelting point eutectic mixture.Electrolysis of this molten salt solution gives the freemetal.[5]
Samarium(III) chloride can also be used as a starting point for the preparation of othersamariumsalts. The anhydrouschloride is used to prepareorganometallic compounds of samarium, such as bis(pentamethylcyclopentadienyl)alkylsamarium(III) complexes.[6]
