Dimethylglyoxime
Names
IUPAC name
Other names Dimethylglyoxime Diacetyl dioxime Butane-2,3-dioxime Chugaev's reagent
Identifiers
95-45-4
ChEMBL
ChemSpider	10606175
ECHA InfoCard	100.002.201
EC Number
PubChemCID
RTECS number	EK2975000
UNII
CompTox Dashboard(EPA)
InChI=1S/C4H8N2O2/c1-3(5-7)4(2)6-8/h7-8H,1-2H3/b5-3-,6-4+ InChI=1/C4H8N2O2/c1-3(5-7)4(2)6-8/h7-8H,1-2H3/b5-3-,6-4+
CC(=NO)C(C)=NO
Properties
C₄H₈N₂O₂
Molar mass	116.120 g·mol⁻¹
Appearance	White/Off White Powder
Density	1.37 g/cm³
Melting point	240 to 241 °C (464 to 466 °F; 513 to 514 K)
Boiling point	decomposes
low
Structure
0
Hazards
Main hazards	Toxic, Skin/Eye Irritant
Safety data sheet	External MSDS
GHS pictograms
GHS Signal word	Danger
H228, H301
P210, P240, P241, P264, P270, P280, P301+310, P321, P330, P370+378, P405, P501
NFPA 704 (fire diamond)
Related compounds
Hydroxylamine salicylaldoxime
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Dec 20, 2006 A bulk modulus of Ni(dmg) 2 is obtained from the volume versus pressure curve fitted by a Birch equation of state. The bulk modulus of this complex is very small, 8.0 GPa. Ni(dmg) 2 is a very compressible compound. The electrical and optical properties of Ni(dmg) 2 have been investigated at high pressures. The dπ–π. and 3d–4p bands shift to a lower energy region with increasing pressure.
2 + 2 dmg All of the complexes are Ni2+octahedral except from Ni(CN) 4 2-which is a Ni2+ square planer complex. As the strength of the field ligand increases the field splitting increase. The ligands, used in this demonstration, listed in order of increasing field strength are.

If the pH does become too low the equilibrium of the above reaction favors the formation of the nickel (II) ion, causing the dissolution of Ni (DMG) 2 back into the mother liquor. A slight excess of the reagent has no action on the precipitate, but a large excess should be avoided because of the possible precipitation of the reagent itself. Any green precipitate formation is due to Ni(OH)2 precipitate. (Add more ammonia to make it go away.) Make the ethylene diamine solution fresh if there are crystals present in the solution or if it’s more than a year old. The ethylene diamine will oxidize with time. Nickel-dimethylglyoxime complex (abbreviated as Ni(II)(DMG)2) modified carbon paste and graphite electrodes were prepared by mixing Ni(II)(DMG)2 with graphite paste, and coating Ni(II)(DMG)2 to the.

Dimethylglyoxime is a chemical compound described by the formula CH₃C(NOH)C(NOH)CH₃. Its abbreviation is dmgH₂ for neutral form, and dmgH for anionic form, where H stands for hydrogen. This colourless solid is the dioxime derivative of the diketone butane-2,3-dione (also known as diacetyl). DmgH₂ is used in the analysis of palladium or nickel. Its coordination complexes are of theoretical interest as models for enzymes and as catalysts. Many related ligands can be prepared from other diketones, e.g. benzil.

Preparation[edit]

Dimethylglyoxime can be prepared from butanone first by reaction with ethyl nitrite to give biacetyl monoxime. The second oxime is installed using sodium hydroxylamine monosulfonate:^[1]

Complexes[edit]

Dimethylglyoxime is used to detect and quantify nickel, which forms the bright red complex nickel bis(dimethylglyoximate) (Ni(dmgH)₂). The reaction was discovered by L. A. Chugaev in 1905.^[2]

Cobalt complexes have also received much attention. In chloro(pyridine)cobaloxime^[3] the macrocycle [dmgH]₂²⁻ mimics the macrocyclic ligand found in vitamin B12.

Structure of chloro(pyridine)cobaloxime.

References[edit]

Ni Dmg 2 2 Structure 2

^Semon, W. L.; Damerell, V. R. (1930). 'Dimethylglyoxime'. Organic Syntheses. 10: 22. doi:10.15227/orgsyn.010.0022.CS1 maint: multiple names: authors list (link)
^Lev Tschugaeff (1905). 'Über ein neues, empfindliches Reagens auf Nickel'. Berichte der Deutschen Chemischen Gesellschaft. 38 (3): 2520–2522. doi:10.1002/cber.19050380317.
^Girolami, G.. S.; Rauchfuss, T.B.; Angelici, R. J. (1999). Synthesis and Technique in Inorganic Chemistry: A Laboratory Manual (3rd ed.). pp. 213–215.

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Nickel(II) hydroxide
Names
IUPAC name
Other names Nickel hydroxide, Theophrastite
Identifiers
12054-48-7 36897-37-7 (monohydrate)
ChemSpider
ECHA InfoCard	100.031.813
EC Number	235-008-5
RTECS number
CompTox Dashboard(EPA)
Key: BFDHFSHZJLFAMC-UHFFFAOYSA-L Key: BFDHFSHZJLFAMC-NUQVWONBAJ
[Ni+2].[OH-].[OH-]
Properties
Ni(OH)₂
Molar mass	92.724 g/mol (anhydrous) 110.72 g/mol (monohydrate)
Appearance	green crystals
Density	4.10 g/cm³
Melting point	230 °C (446 °F; 503 K) (anhydrous, decomposes)
0.13 g/L
+4500.0·10⁻⁶ cm³/mol
Structure^[1]
hexagonal, hP3
P3m1, No. 164
α = 90°, β = 90°, γ = 120°
Thermochemistry
79 J·mol⁻¹·K⁻¹^[2]
Std enthalpy of formation(Δ_fH^⦵₂₉₈)	−538 kJ·mol⁻¹^[2]
Hazards
Safety data sheet	External SDS
GHS pictograms	^[3]
GHS Signal word	Danger^[3]
H302, H332, H315, H334, H317, H341, H350, H360, H372^[3]
P260, P284, P201, P280, P405, P501^[3]
Lethal dose or concentration (LD, LC