1,5-DIBROMOPENTANE

PRODUCT IDENTIFICATION
CAS NO. 111-24-0

1,5-DIBROMO PENTANE
EINECS NO. 203-849-7
FORMULA Br(CH2)5Br
MOL WT. 229.94

H.S. CODE

 2903.39.1550
TOXICITY  
SYNONYMS Pentamethylene Dibromide; 1,5-Dibromo-n-pentane; DBP;

SMILES

C(CCBr)CCBr

CLASSIFICATION

Halogenoalkane

PHYSICAL AND CHEMICAL PROPERTIES
PHYSICAL STATE clear to pale yellow liquid
MELTING POINT -35 C
BOILING POINT 222 - 224 C
SPECIFIC GRAVITY 1.68 - 1.71
SOLUBILITY IN WATER Insoluble
pH 6.0 - 8.0
VAPOR DENSITY  

AUTOIGNITION

 
pKa (at 20 C)
log Pow 3.48 (Octanol-water)
VAPOR PRESSURE (mmHg)
HENRY'S LAW (atm-m3/mole at 25 C)
OH RATE 3.11E-12 (cm3/molecule-sec at 25 C Atmospheric)

NFPA RATINGS

 Health: 1; Flammability: 2; Reactivity: 0

REFRACTIVE INDEX

 1.5126
FLASH POINT 80 C
STABILITY Stable under ordinary conditions.

GENERAL DESCRIPTION & EXTERNAL LINKS
Halogenoalkanes, also known as haloalkanes or alkyl halides, are organic compounds in which one or more hydrogen atoms in an alkane have been replaced by halogen atoms, fluorine, chlorine, bromine or iodine. In carbon-halogen bond, halogens have significantly greater electronegativities than carbon except iodine. In result, this functional group is polarized so that the carbon is electrophilic and the halogen is nucleophilic. Halogenoalkanes are can be classified depending on the halogen atom position on the chain of carbon atoms. The carbon which is attached with the halogen atom is linked up with only one other alkyl group in primary halogenoalkanes, whereas directly linked up with two and three other alkyl groups in secondary halogenoalkanes and tertiary halogenoalkanes respectively. In some case, primary halogenoalkanes are counted even though there are no alkyl groups attached to the carbon with the halogen on it. Three characteristics provide important influences on the chemical behavior of halogenoalkanes, these are electronegativity, covalent bond strength and the relative stability of the corresponding halide anions.  Fluoroalkanes have the strongest of the carbon-halogen covalent bonds so that they are unreactive. This is stronger single bond than a carbon-carbon bond. The carbon-chlorine covalent bond is slightly weaker than a carbon-carbon bond, and the bonds to the other halogens are weaker. The stability may be estimated from the relative acidities of the H-X acids. All the hydrohalic acids are very strong, but with small differences in the direction HCl < HBr < HI, with the exception of HF. Halogenoarenes, also called haloarene, or aryl Halide, are  an organic compound in which one or more hydrogen atoms in an aromatic ring have been replaced by halogen atoms. The Haloarenes exhibit many differences compare to haloalkanes in the method of preparation and their chemical and phisical properties. Haloalkanes are used in as refrigerants, solvents, blowing agents, aerosol propellants, fire extinguishing media , and in semiconductor device fabrication. One of big consumption of halogenoalkanes (properly speaking, halogenoalkenes) is as a raw material to prepare plastics such as PVC [poly(chloroethene)] from chloroethene and PTFE [poly(tetrafluoroethene)] from tetrafluoroethene. Halogenoalkanes and halogenoarenes react with lots of compounds resulting in a wide range of different target substances. They are useful intermediates in making other organic compounds.  
  • Summary of substitution and elimination reaction based on alkyl group structure
Alkyl Halides

SN1 and E1

SN2 and E2

Primary (RCH2X) Neither SN1 nor E1 occur both SN2 and E2 will occur
(SN2 preferred. E2 preferred when sterically hindered base is used)
Secondary (R2CHX) will occur slowly in high dielectric ionizing solvents
( SN1 preferred)		 both SN2 and E2 will occur
(SN2 preferred if base is weaker than acetate, pKa = 4.8, E2 preferred if base is strong)
Tertiary (R3CX) both SN1 and E1 will occur
(SN1 preferred)		 No SN2 will occur
E2 will dominate if base is strong

Allyl (H2C=CHCH2X)

 will occur slowly in high dielectric ionizing solvents Rapid SN2 for primary and secondary halides but slow for tertiary. E2 when nucleophile is basic.

Benzyl (C6H5CH2X)

 will occur slowly in high dielectric ionizing solvents Rapid SN2 for primary and secondary halides but slow for tertiary. E2 when nucleophile is basic.
  • SN1 and SN2 reaction order based on alkyl group structure
    • SN2 :  CH3X (100%) > RCH2X > R2CHX > R3CX
    • SN1 :  CH3X < RCH2X < R2CHX < R3CX (100%)
  • Nucleophilicity order
    • F- < Cl- < Br- < I-  In a protic solvent which decrease SN2 rate due to solvating nucleophile
    • F- > Cl- > Br- > I- In a polar aprotic solvent which increase SN2 reaction due to no solvating nucleophile
    • F- > Cl- > Br- > I-  SN2 in the gas phase
(Both protic and aprotic polar solvent  enhance SN1 due to the stabilization of the carbocation intermediate)
  • Leaving group Among halogens: I > Br > Cl > F

Wikipedia Linking: http://en.wikipedia.org/wiki/Haloalkane

http://www.chemguide.co.uk/
INTRODUCING HALOGENOALKANES (haloalkanes or alkyl halides)
Halogenoalkanes are also known as haloalkanes or alkyl halides. This page explains what they are and discusses their physical properties. It also takes an initial look at their chemical reactivity. Details of the chemical reactions of halogenoalkanes are described on separate pages.
What are halogenoalkanes? Halogenoalkanes are compounds in which one or more hydrogen atoms in an alkane have been replaced by halogen atoms (fluorine, chlorine, bromine or iodine). For the purposes of UK A level, we will only look at compounds containing one halogen atom......
SALES SPECIFICATION

APPEARANCE

 clear to pale yellow liquid

CONTENT

99.0% min

NONVOLATILES

50ppm max

MOISTURE

0.05% max

TRANSPORTATION
PACKING  
HAZARD CLASS 3 (Packing Group: III)
UN NO. 1993
OTHER INFORMATION
Hazard Symbols: XI, Risk Phrases: 36/37/38, Safety Phrases: 24/25