trans -Dichlorobis (ethylenediamine) cobalt (III) chloride

Structural formula
General
Surname	trans -Dichlorobis (ethylenediamine) cobalt (III) chloride
Molecular formula	C 4 H 16 Cl 3 CoN 4
Brief description	dark green, shiny crystals
External identifiers / databases
CAS number 14040-33-6 PubChem 12127156 ChemSpider 62872697 Wikidata Q55636107
properties
Molar mass	285.48 g mol −1
Physical state	firmly
Melting point	Decomposes at 237-239 ° C
solubility	good in water bad in most organic solvents
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 315-319-335 P: 261-305 + 351 + 338
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

trans -Dichlorobis (ethylenediamine) cobalt (III) chloride is an organometallic compound of cobalt with the empirical formula [CoCl ₂ (C ₂ H ₈ N ₂ ) ₂ ] Cl. The dark green shiny crystals are diamagnetic and easily soluble in water.

synthesis

trans -Dichlorobis (ethylenediamine) cobalt (III) chloride can be by offsetting of cobalt (II) chloride with ethylenediamine with concentrated introduction of air and subsequent reaction of hydrochloric acid win.

${\displaystyle {\ce {4 CoCl2 + 8 C2H8N2 + 4 HCl + O2 -> 4 [CoCl2(C2H8N2)2]Cl + 2 H2O}}}$

The product contains hydrochloric acid, which is removed from the solution by evaporation.

properties

trans -Dichlorobis (ethylenediamine) cobalt (III) chloride

trans -Dichlorobis (ethylenediamine) cobalt (III) chloride forms dark green, glossy crystals that are stable in air at room temperature. The green trans form is subject to isomerization to the cis form in aqueous solution , the equilibrium constant of the reaction at 23.0 ° C is:

${\displaystyle K_{c}=\mathrm {\frac {[cis]}{[trans]}} =11,60}$

If the crystals are heated until they melt, the complex turns into a resin-like elastic material. When it is dissolved, the complex breaks down into its components again in this state. The resulting cobalt (II) chloride produces a brown to reddish color.

Individual evidence

1. ↑ ^{a b c d e} John C. Bailar Jr., Carl L. Rollinson: cis‐ and trans ‐ Dichlorobis– (ethylenediamine) cobalt (III) Chloride and the Resolution of the cis Form . In: W. Conard Fernelius (Ed.): Inorganic Syntheses . tape 2 . McGraw-Hill, New York / London 1946, ISBN 978-0-470-13233-3 , pp. 222-225 , doi : 10.1002 / 9780470132333.ch71 .
2. ↑ ^{a b c} data sheet trans-Dichlorobis (ethylenediamine) cobalt (III) chloride from Sigma-Aldrich , accessed on June 23, 2018 ( PDF ).
3. ↑ DT Haworth, EF Neuzil, SL Kittsley: Thermodynamics of the cis-trans interconversion of dichlorobis- (ethylenediamine) -cobalt (III) chloride . In: Experientia . tape 12 , no. 9 , 1956, pp. 335-335 , doi : 10.1007 / BF02165334 .
4. ↑ Robert C. Brasted, Chikara Hirayama: The cis-trans Isomerization of Dichlorobis- (ethylenediamine) -cobalt (III) Chloride and Dichlorobis- (propylenediamine) -cobalt (III) Chloride in Alcohols . In: Journal of the American Chemical Society . tape 80 , no. 4 , 1958, pp. 788-794 , doi : 10.1021 / ja01537a009 .