What Is Copper Acetate?

Copper acetate, monohydrate is blue-green powdery crystals. The crystal water is removed at 240 ° C. It is soluble in ethanol and slightly soluble in ether and glycerol. Used as analytical reagent, chromatographic analysis reagent, and also used as organic synthesis catalyst, paint fast-drying agent, pesticide auxiliary, raw material of enamel pigment, etc.

Chinese name: Copper acetate
English name: Cupric Acetate Monohydrate
nickname: Copper acetate
Chemical formula: Cu (CH3COO) 2 · H2O
Molecular weight: 199.65
CAS Registry Number: 6046-93-1
EINECS registration number: 205-553-3

Melting point: 115
Water soluble: 7.2g / 100mL (cold water), 20g / 100ml (hot water)
Density: 1.882 g / cm3
Exterior: Blue-green crystal
Application: Chromatographic analysis, organic synthesis, etc.
Danger symbol: N, Xn
Risk description: Environmentally hazardous substances
Dangerous Goods Transport Number: UN 9106/3077

Copper acetate structure

Copper (II) acetate monohydrate, and similar Rh (II) and Cr (II) tetraacetates all adopt a "Chinese lantern" structure. As shown in the figure, one oxygen atom of each acetate is bonded to one copper atom, the Cu-O bond length is 197pm; the two water molecule ligands occupy the upper and lower, and the Cu-O bond length is 220pm. The distance between two five-coordinated copper atoms is 265pm, which is close to the Cu-Cu distance (255pm) in metallic copper. This Cu2 (OAc) 4 (H2O) 2 dimer unit structure is mainly bonded by hydrogen bonding in the crystal. Other small molecular ligands such as dioxane, pyridine and aniline can replace the water in the dimer. molecule. ^[1]

The two copper atoms interact with each other. At room temperature, the magnetic moment is 1.40BM, but decreases with decreasing temperature (such as 0.36BM at 93K). At 253K, the magnetic susceptibility exhibits a maximum value. From this, the adjacent The exchange between copper atoms is 286 cm-1, indicating that the copper atoms in the dimer are bonded by a weak covalent bond. Due to the opposite cancellation of the spin directions, Cu2 (OAc) 4 (H2O) 2 is essentially antimagnetic, and this structure has made an important contribution to the development of modern antiferromagnetic coupling theory. ^[1]

Synthetic method and properties of copper acetate

Copper acetate synthesis method

Preparation method in the laboratory:

Dissolve 50 g of copper sulfate pentahydrate in 500 ml of water, filter, dissolve another 57 g of sodium carbonate decahydrate in 240 ml of water, heat to 60 ° C, slowly add the copper sulfate solution, and keep stirring. Let it stand, filter out the precipitate, wash it with hot water until there is no sulfuric acid, put the precipitate in 300 ml of water, add 2 ml of ammonia water and stir, let it stand, pour out the upper solution, and wash and precipitate several times. Add 180 ml of water to a beaker, heat to 60 ° C, add 22 g of glacial acetic acid, and then add the washed basic copper carbonate until there is a little left at the bottom of the container. After filtration, the filtrate was concentrated by evaporation to 1/3 of the original volume, cooled, filtered, washed with 2 ml of water, and dried at room temperature to obtain a finished product. The mother liquor continues to evaporate, and 5ml of 25% acetic acid is added when the crystals are about to come out, and part of the finished product can be obtained. It was 32-35 g. ^[2]

The total response is:

2 CuSO4 · 5H2O + 4 NH3 + 4 HOAc Cu2 (OAc) 4 (H2O) 2 + 2 (NH4) 2SO4 + 8 H2O

Copper acetate properties

Monohydrate will lose water under vacuum at 100 ° C:

Cu2 (OAc) 4 (H2O) 2 Cu2 (OAc) 4 + 2 H2O

Reduction of copper acetate with copper, hydrazine hydrate, etc. in a non-aqueous solvent will give colorless and volatile cuprous acetate:

2 Cu + Cu2 (OAc) 4 2 Cu2 (OAc) 2

2 Cu2 (OAc) 4 + N2H4 · H2O == 2 Cu2 (OAc) 2 + 4 HOAc + N2 ^[1]

Note: Acetic acid (CH3COOH) can be expressed as HOAc

Copper acetate application

Organic Synthesis of Copper Acetate

Copper acetate is used more as a catalyst or oxidant in organic synthesis. For example, Cu2 (OAc) 4 can catalyze the coupling of two terminal alkynes, and the product is 1,3-diyne:

Cu2 (OAc) 4 + 2 RCCH 2 CuOAc + RCCCCR + 2 HOAc

The intermediates of the reaction include copper acetylene and the like, and then oxidized with copper acetate to obtain alkynyl radicals.

In addition, the synthesis of alkynamines (terminal alkynes containing amino groups) from copper acetate also involves copper acetylene intermediates.

Copper acetate

Reaction principle:

Making specimens from copper acetate (2 photos)

The H + in the demagnesium chlorophyll is replaced by Cu2 + again to form a copper-substituted chlorophyll, which is more bright and stable than the original chlorophyll. According to this principle, green plant specimens can be preserved by treatment with copper acetate.

Specimen method:

Plant specimens are impregnated with a saturated copper acetate solution prepared in 50% acetic acid solution (heatable during processing)

Copper acetate technical index

Copper acetate	Export high purity	Analytical pure	Chemically pure	Refined grade	Industrial grade
Item	Indicator	Indicator	Indicator	Indicator	Indicator
content%	99.0	99.0	98.0	98.0	98.0
Sulfate (SO4)%	0.005	0.01	0.02	0.05	0.1
Hydrogen sulfide not precipitated		0.1	0.3	0.3	0.5
Water insoluble matter%	0.005	0.02	0.05	0.1
Lead (Pb)	0.005	0.002	0.005	0.005	0.005
Iron (Fe)%	0.002	0.002	0.005	0.01
Chloride (Cl)	0.001	0.003	0.005	0.01	0.05
Zinc (Zn)%	0.002			0.02
Nitrate (NO3)		0.01
Calcium (Ca)%	0.01
Magnesium (Mg)%	0.002
Nickel (Ni)%	0.002
Potassium (K)%	0.01
Sodium (Na)%	0.01
Barium (Ba)%	0.05
PH (5% solution)	5.0-5.5

Copper acetate substance toxicity

Non-toxic to mildly toxic, with LD50 (oral, rodent-rat) 710 mg / kg ^[3] and LDLo (oral, rodent-rat) 1600 mg / kg ^[4]

Toxicity test data
Numbering	Toxicity type	testing method	Test object	Dosage used	Toxic effect
1	Acute toxicity	oral	Rat	501 mg / kg	1. Behavioral toxicity-lethargy 2. Behavioral toxicity-affected by convulsions or seizure thresholds
2	Acute toxicity	Intraperitoneal injection	Rat	14700 ug / kg	1. Behavioral toxicity-lethargy 2. Behavioral toxicity-affected by convulsions or seizure thresholds
3	Acute toxicity	Subcutaneous injection	Rat	350 mg / kg	1. Skeletal muscle toxicity-affecting joints 2. Carcinogenicity-anti-tumor, anti-cancer activity 3. Biochemical toxicity-affecting inflammation or the regulation of inflammation
4	Acute toxicity	Intravenous injection	Rat	17100 ug / kg	1. Behavioral toxicity-lethargy 2. Behavioral toxicity-affected by convulsions or seizure thresholds
5	Acute toxicity	oral	Mouse	196 mg / kg	1. Behavioral toxicity-lethargy 2. Behavioral toxicity-affected by convulsions or seizure thresholds
6	Acute toxicity	Intraperitoneal injection	Mouse	2500 ug / kg	Detailed effects are not reported other than lethal dose
7	Acute toxicity	Intravenous injection	Mouse	20 mg / kg	1. Behavioral toxicity-lethargy 2. Behavioral toxicity-affected by convulsions or seizure thresholds
8	Acute toxicity	oral	rabbit	250 mg / kg	Detailed effects are not reported other than lethal dose
9	Chronic toxicity	oral	Rat	23750 mg / kg / 42W-C	1. Lung, chest or respiratory toxicity-pulmonary interstitial fibrosis, lung disease (including pneumoconiosis) 2. Hepatotoxicity-other changes 3. Kidney, ureter and bladder toxicity-other changes
10	Chronic toxicity	Intraperitoneal injection	Rat	56 mg / kg / 7D-I	1. Hematological toxicity-other changes 2. Nutrition and metabolic system toxicity-changes in metal ion concentration 3. Biochemical toxicity-inhibition or induction of other enzymes
11	Chronic toxicity	oral	monkey	3360 mg / kg / 24W-C	1. Liver toxicity-other changes 2. Chronic disease-related toxicity-death
12	Chronic toxicity	oral	rabbit	21840 mg / kg / 2Y-C	1. Cerebral toxicity-other degenerative changes 2. Liver toxicity-other changes 3. Chronic disease-related toxicity-death
13	Chronic toxicity	oral	rabbit	17500 mg / kg / 50W-C	1. Liver toxicity-hepatitis, fiber (cirrhosis, post-necrotic scar) 2. Hepatotoxicity-jaundice, others not classified 3. Chronic disease-related toxicity-death
14	Chronic toxicity	Subcutaneous injection	rabbit	100 mg / kg / 1W-I	1. Lung, chest or respiratory toxicity-chronic pulmonary edema 2. Hepatotoxicity-hepatitis (hepatocyte necrosis), banding 3. Chronic disease-related toxicity-death
15	Chronic toxicity	Subcutaneous injection	mammal	23333 ug / kg / 26W-I	1. Liver toxicity-changes in liver weight 2. Kidney, ureter and bladder toxicity-changes in renal tubules (including acute renal failure, acute tubular necrosis) 3. Endocrine toxicity-changes in spleen weight
16	Reproductive toxicity	Subcutaneous injection	Rat	40 mg / kg, 7-10 days after conception	1. Reproductive toxicity-affect fertility

^[5-12]

Copper acetate precautions

It should be stored in a ventilated and dry warehouse. The mouth of the bag must be tightly sealed to prevent moisture. Open flames and flammable materials are strictly prohibited.