Views: 5 Author: Site Editor Publish Time: 2022-08-03 Origin: Site
N. N-dimethylformamide, an organic compound with the chemical formula C3H7NO, is a colorless transparent liquid. It is not only a widely used chemical raw material, but also a widely used excellent solvent. Except halogenated hydrocarbons, it can be mixed with water and most organic solvents at will, and has good solubility for a variety of organic and inorganic compounds.
Chemical formula: C3H7NO
Molecular weight: 73.095
CAS No.: 68-12-2
EINECS No.: 200-679-5
MDL No.: mfcd00003284
RTECS No.: lq2100000
BRN No.: 605365
Melting point: -61 ℃
Boiling point: 153 ℃
Flash point: 58 ℃ (OC)
Density: 0.948g/cm3
Refractive index: 1.430 (20 ℃)
Saturated vapor pressure: 0.5kpa (25 ℃)
Critical temperature: 374 ℃
Critical pressure: 4.48mpa
Ignition temperature: 445 ℃
Upper explosion limit (v/v): 15.2%
Lower explosive limit (v/v): 2.2%
Appearance: colorless transparent liquid
Solubility: miscible with water and most organic solvents
Molar refractive index: 19.85
Molar volume (cm3/mol): 82.6
Isotonic specific volume (90.2k): 186
Surface tension (dyne/cm): 25.7
Dielectric constant (f/m): 36.7
Dipole distance (d): 3.86 (1d=3.33 × 10-30C·m)
Polarizability (10-24 cm3): 7.87 [2]
Reference value of hydrophobic parameter calculation (xlogp): -1
Number of hydrogen bond donors: 0
Number of hydrogen bond receptors: 1
Number of rotatable chemical bonds: 0
Topological molecular polarity surface area (TPSA): 20.3
Number of heavy atoms: 5
Surface charge: 0
Complexity: 33.9
Number of isotope atoms: 0
Determine the number of atomic structure centers: 0
Number of atomic stereocenters of uncertainty: 0
Determine the number of chemical bond conformation centers: 0
Number of indeterminate chemical bond conformation centers: 0
Number of covalent bond units: 1 [2]
1. Acute toxicity
Ld50:4000mg/kg (rat oral); 4720mg/kg (rabbit percutaneous)
Lc50:9400mg/m3 (inhalation in mice, 2h)
2. Irritation: rabbit eye: 100%, severe irritation (rinse with water)
3. Subacute and chronic toxicity: rats inhaled 2500 mg per cubic meter, 6 hours a day, for a total of 5 days. 8~10 of the 16 rats died. Autopsy showed liver and lung damage.
1. Ecotoxicity
Lc50:1430mg/l (96h) (Pseudosciaena crocea); 10000~13000mg/l (96h) (rainbow trout)
2. Non biodegradability: in air, when the concentration of hydroxyl radical is 5 /cm3, the degradation half-life is 22h (Theory). [1]
It is not only a widely used chemical raw material, but also a widely used excellent solvent.
Metabolism: after absorption through various ways, DMF is mainly metabolized in the liver and excreted rapidly. The main target organ is the liver, and there is also some damage to the kidney. Demethylation is mainly carried out by microsomal mixed function oxidase in the liver, and a methyl is removed. The metabolites are methylformamide and formamide, which are metabolized rapidly; Formamide stays in the blood for a little longer, and then is metabolized into formic acid and ammonia. Part of dimethylformamide is discharged from urine and exhalation as prototype.
Health hazard: irritating to eyes, skin and respiratory tract. Steam can cause mild and moderate irritation of eyes and upper respiratory tract. Polluting the skin can cause light and heavy burns, wrinkled skin, white skin, accompanied by burning pain, and serious cases can make the skin swollen and intense burning pain. The polluted eyes cause burning pain, tears and conjunctival congestion; Severe cases can cause corneal necrosis.
Gastrointestinal symptoms: patients often have anorexia, nausea, vomiting, abdominal discomfort and constipation, and a few cases have middle and upper abdominal pain.
Liver: during acute poisoning, liver damage is often prominent, the patient has obvious fatigue, right upper abdomen swelling and pain, discomfort, jaundice, liver gradually swelling, tenderness, routine liver function examination shows abnormalities, in which the serum transaminase rises significantly. The disease is generally not serious, which can be gradually reduced after treatment, and the disease can be completely recovered within a few weeks.
Severe acute poisoning: it shows severe toxic liver disease, occupational poisoning is rare, exposure to high concentration, especially serious skin pollution, and those who do not wash thoroughly in time should be alert to serious poisoning.