Technetium(III) chloride

Technetium(III) chloride
Names
	Other names Technetium(III) chloride
Identifiers
CAS Number	1255775-02-0;
3D model (JSmol)	Interactive image;
ChemSpider	26946114;
	InChI InChI=1S/3ClH.Tc/h3*1H;/q;;;+3/p-3 Key: XAEYUXPVCBLTEP-UHFFFAOYSA-K;
	SMILES [Cl-].[Cl-].[Cl-].[Tc+3];
Properties
Chemical formula	Cl3Tc
Molar mass	204 g·mol−1
Appearance	black solid
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Technetium trichloride is an inorganic compound of technetium and chlorine with the formula TcCl₃.

Preparation and properties

Two polymorphs of technetium trichloride are known. The α-polymorph is prepared as a black solid from ditechnetium(III) tetraacetate dichloride and hydrogen chloride at 300 °C. It has a bioctahedral structure, consisting of triangular Tc₃Cl₉ units with C_3v symmetry, with each Tc atom coordinated to two Tc neighbors and five chloride ligands (Tc-Tc bond length 2.44 angstrom). The Tc-Tc distances are indicative of double bonded Tc atoms. Tc₃Cl₉ is isostructural to its rhenium homologue, trirhenium nonachloride.^[1]

β-TcCl₃ is obtained by the reaction between technetium metal and chlorine gas. Its structure consists of infinite layers of edge-sharing octahedra, similar to MoCl₃ and ReCl₃, with distances that also indicate metal-metal bonding. It is less stable than α-TcCl₃ and slowly transforms into it.^[1]

References

^ ^a ^b Poineau, Frederic; Johnstone, Erik V.; Weck, Philippe F.; Kim, Eunja; Forster, Paul M.; Scott, Brian L.; Sattelberger, Alfred P.; Czerwinski, Kenneth R. (2010). "Synthesis and Structure of Technetium Trichloride". Journal of the American Chemical Society. 132 (45): 15864–5. doi:10.1021/ar400225b. PMID 24393028.

[Al-1] Poineau, Frederic; Johnstone, Erik V.; Weck, Philippe F.; Kim, Eunja; Forster, Paul M.; Scott, Brian L.; Sattelberger, Alfred P.; Czerwinski, Kenneth R. (2010). "Synthesis and Structure of Technetium Trichloride". Journal of the American Chemical Society. 132 (45): 15864–5. doi:10.1021/ar400225b. PMID 24393028.

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