FLUOROBENZENE
|
PRODUCT
IDENTIFICATION
|
CAS
NO. |
462-06-6 |
|
EINECS
NO |
207-321-7 |
FORMULA |
C6H5F |
MOL
WT. |
96.103 |
H.S.
CODE |
|
TOXICITY
|
Oral rat LD50: 4399 mg/kg |
SYNONYMS |
Phenyl Fluoride; monofluorobenzene; |
SMILES
|
|
CLASSIFICATION
|
|
PHYSICAL AND CHEMICAL PROPERTIES
|
PHYSICAL
STATE |
Colorless liquid |
MELTING POINT |
-41
C |
BOILING
POINT |
85
C
|
SPECIFIC GRAVITY |
1.024 |
SOLUBILITY
IN WATER |
Insoluble |
pH |
|
VAPOR DENSITY |
3.31 |
AUTOIGNITION
|
|
REFRACTIVE
INDEX
|
1.4650 |
NFPA
RATINGS
|
Health:- ; Flammability: 3; Reactivity: 0 |
FLASH
POINT |
-15
C
|
STABILITY |
Stable under ordinary
conditions |
APPLICATIONS
|
Fluorobenzene
is used to control carbon content in steel manufacturing.
It is an intermediate for pharmaceuticals, pesticides and other organic compounds. When substituted benzene molecules undergo electrophilic substitution reactions,
substituents on a benzene ring can influence the reactivity.
Activating
substituents that activate the benzene ring toward electrophilic
attack can alter the reaction rate or products by
electronically or sterically affecting the interaction of the two reactants.
deactivating substituents removes electron density from the benzene ring, making
electrophilic aromatic
substitution reactions slower and more difficult than benzene itself. For example, a hydroxy or methoxy substituent in
phenol and anisole increases the rate of
electrophilic substitution, while a nitro
substituent decreases the ring's reactivity. Electron donating
substituents activate the benzene ring toward electrophilic
attack, and electron withdrawing substituents deactivate the ring, making it less reactive to electrophilic attack.
The strongest activating substituents are the amino
(-NH2) and hydroxyl (-OH) groups.
Reactivity Effects |
Activating substituents |
Deactivating substituents |
Strong |
-NH2,
-NHR, -NR2,
-OH, -O-
|
-NO2,
-NR3+,
-CF3, CCl3
|
Moderate |
-NHCOCH3,
-NHCOR, -OCH3,-OR
|
-CN,
-SO3H,
-COOH, -COOR, -COH, -COR
|
Weak |
-CH3,
-C2H5,
-R, -C6H5
|
-F,
-Cl, -Br, -I
|
Toluene, aniline and phenol
are activated aromatic compounds. Examples of deactivated aromatic compounds
are nitrobenzene, benzaldehyde and halogenated benzenes.
Activating substituents
generally direct substitution to the ortho and para positions
where substitutions must
take place. With some
exceptions, deactivating substituents direct to the meta position. Deactivating substituents
which orient ortho
and para- positions are the halogens (-F, -Cl, -Br, -I) and -CH2Cl,
and -CH=CHNO2
When disubstituted benzene molecules undergo electrophilic substitution reactions,
a new substituent is directed depends on the orientation of
the existing substituents and their individual effects; whether the groups have cooperative or antagonistic directing effects.
Ortho position is the most reactive towards electrophile
due to the highest electron density ortho positions.
But this increased reactivity is countervailed by steric hindrance between substituent and
electrophile. A nucleophilic substitution is a substitution reaction which the nucleophile
displaces a good leaving
group, such as a halide on an aromatic ring. This
mechanism is called SNAr
( the two-step addition-elimination mechanism), where electron withdrawing substituents activate
the ring towards nucleophilic attack. Addition-elimination reactions usually
occur at sp2 or sp
hybridized carbon atoms, in contrast to SN1 and SN2
at sp3.
Chloro and bromobenzene reacts with the very
strong base sodium amide (NaNH2) to give good yields of aniline.
Other nucleophilic aromatic substitution mechanisms
include benzyne mechanism and free radical
(SRN1) mechanism.
Common
reactions of substituent groups on benzene ring include:
- Conversion of halogens
into other various substituents
- Modifying activating substituents
- Oxidative degradation of
alkyl chain
- Reduction of
nitro or carbonyl substituents
- Reversibility of the aromatic sulfonation reaction
|
SALES
SPECIFICATION |
APPEARANCE
|
Colorless liquid |
PURITY
(G.C) |
99.5%
min |
TRANSPORTATION |
PACKING |
200kgs
in drum |
HAZARD CLASS |
3
(Packing group II) |
UN
NO. |
2387 |
GENERAL DESCRIPTION OF FLUORINE AND ITS COMPOUNDS |
Fluorine (Symbol : F; Atomic no. 9 ) is a yellowish,
poisonous, corrosive gas under ordinary conditions. Fluorine becomes a yellow
liquid upon cooling. It is the most reactive nonmetallic element and extremely
powerful oxidizing agent. Because of its extreme reactivity, fluorine does not
occur uncombined in nature. Fluorine occurs widely combined in the mineral
fluorspar( fluorite, the chief commercial source), cryolite and apatite. The
preparation of the free element is carried out by the electrolysis of a molten
mixture of hydrogen fluoride, HF, and potassium fluoride, KF in the absence of
water. Fluorine can be safely stored under pressure in cylinders of stainless
steel if the valves of the cylinders are free from traces of organic matter. The
outstanding oxidizing properties of the elemental gas are used in some rocket
fuels. The element may be used for the fluorination of organic compounds with
appropriate precautions. The element is used for manufacturing various fluorides
including chlorine trifluoride ans cobalt(III) fluoride which are important
fluorinating agents for organic compounds, sulfur(VI) fluoride used as a gaseous
electrical insulator. Boron trifluoride and antimony trifluoride like hydrogen
fluorides are important catalysts for alkylation reactions used to prepare
organic compounds. Sodium fluoride (NaF) is used to treat dental caries and is
often used for the fluoridation of drinking water to reduce tooth decay
(However, there are reports of an accompanying risk of fluoride toxicity ). The
element is also used for the preparation of uranium(VI) fluoride, utilized in
the gaseous diffusion process of separating uranium-235 from uranium-238
(natural uranium) for reactor fuel. The importance of fluorine lies largely in
its extreme ability to attract electrons and to the small size of its atoms,
which can be attributed to form many stable complexes with positive ions like
hexafluorosilicate(IV) and hexafluoroaluminate(III). Fluorine derivatives of
hydrocarbons (compounds of carbon and hydrogen) are useful extensively as
aerosol-spray propellants, refrigerants, solvents, cleansing agents for
electrical and electronic components, and foaming agents in shipping-plastics
manufacturing. Useful plastics with non-sticking qualities, such as
polytetrafluoroethylene ( known by the trade name Teflon), are readily made from
unsaturated fluorocarbons. A solution of hydrogen fluoride gas in water is
called hydrofluoric acid, largely consumed for cleaning metals and for
polishing, frosting, and etching glass. Hydrofluoric acid is also used as a
catalyst for alkylation reactions. The chemical reactions are similar to those
in the sulfuric acid process, but it is possible to avoid refrigeration. (In
sulfuric acid alkylation, refrigeration is necessary because of the heat
generated by the reaction).
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