Chloro(pyridine)cobaloxime

Chloro(pyridine)cobaloxime(III)

Names
Other names Chloro(pyridine)bis(dimethylglyoximato)cobalt(III), Chloro(N,N'-dihydroxy-2,3-butanediimine-κ2N,N')(N-hydroxy-2,3-butanediiminato-κ2N,N')(methanol)cobalt - pyridine (1:1)
Identifiers
CAS Number	23295-32-1
3D model (Jmol)	Interactive image
ChemSpider	17207432
ECHA InfoCard	100.153.977
PubChem CID	24860975
InChI InChI=1S/2C2H6N2.2ClH.Co/c2*3-1-2-4;;;/h2*3-4H,1-2H2;2*1H;/q2*-2;;;+2/p-2 Key: CZHYJYFFRNANOP-DSUIRYESSA-M InChI=1S/C9H17N4O4.C5H5N.ClH.Co/c1-6(10)7(2)11-16-19-17-13-9(4)8(3)12-15-18-14-5;1-2-4-6-5-3-1;;/h1-5H3;1-5H;1H;/q-1;;; 2/p-1/b11-7 ,12-8 ,13-9 ;;;
SMILES CO[H]O\N1=C(/C)\C(\C)=N2\O[H]O\N3=C(/C)\C(\C)=N/[Co]123Cl.c1ccccn1
Properties
Chemical formula	C13H19ClCoN5O4
Molar mass	403.71 g·mol−1
Appearance	yellow-brown solid
Solubility in water	insoluble
Hazards
R-phrases (outdated)	R36/37/38
S-phrases (outdated)	S26 S37 S38 S39
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Chloro(pyridine)cobaloxime is a coordination compound containing a Co^III center with octahedral coordination. It has been considered as a model compound of vitamin B₁₂ for studying the properties and mechanism of action of the vitamin. It belongs to a class of bis(dimethylglyoximato)cobalt(III) complexes with different axial ligands, called cobaloximes. Chloro(pyridine)cobaloxime is a yellow-brown powder that is sparingly soluble in most solvents, including water.

The complex adopts a distorted octahedral geometry. Cobalt(III) is bound to two dimethylglyoximate ligands, i.e., mono-deprotonated dimethylglyoxime, in the equatorial plane. Completing the coordination sphere are chloride and a pyridine at the axial positions.

The cobaloxime is slowly decomposed by acids and bases. With acids, the products of decomposition are dimethylglyoxime, cobalt salts, and pyridine; with bases, derivatives of other cobaloximes are formed, usually with the release of chloride ions.

The complex has no reaction with hydrogen gas, and cannot carry oxygen as salcomine does. It would, however, react with hydrogen in the presence of sodium hydroxide, a catalytic amount of platinum metal, or a reduced cobaloxime, therefore once the reduction occurs, the hydrogenation would occur much more rapidly as there is .

The reduction products of cobaloxime depends on the conditions. At pH near 7, a cobaloxime with a Co^II center is formed. With a higher pH, the cobalt center would be further reduced to the Co^I state, which is supernucleophilic.

The compound is usually prepared by mixing cobalt(II) chloride, dimethylglyoxime and pyridine in an ethanolic solution. This process afford the cobaloxime(II), which is subsequently oxidized by the oxygen in air:

Using cobalt(II) acetate in place of cobalt(II) chloride produce aceto(pyridine)cobaloxime. This acetate can be converted to the respective bromide, iodide, cyanate, cyanide, azide and thiocyanate.