2,5-Norbornadiene Property

Melting point:

-20--19°C

Boiling point:

89 °C(lit.)

Density 

0.906 g/mL at 25 °C(lit.)

vapor pressure 

69 hPa (20 °C)

refractive index 

n20/D 1.470(lit.)

Flash point:

12 °F

storage temp. 

Store below +30°C.

solubility 

Chloroform (Sparingly)

form 

A liquid

color 

Colorless to Almost colorless

Odor

Very diffusive, gassy-piney, camphoraceous-woody odor

explosive limit

1.6-6.3%(V)

Water Solubility 

Immiscible with water.

λmax

195nm(EtOH)(lit.)

BRN 

506224

Stability:

Volatile

InChIKey

SJYNFBVQFBRSIB-UHFFFAOYSA-N

LogP

2.67 at 25℃ and pH7

Surface tension

64.3-64.4mN/m at 900μg/L and 20.3℃

CAS DataBase Reference

121-46-0(CAS DataBase Reference)

NIST Chemistry Reference

2,5-Norbornadiene(121-46-0)

EPA Substance Registry System

2,5-Norbornadiene (121-46-0)

Safety

Hazard Codes 

F

Risk Statements 

11

Safety Statements 

16-23

RIDADR 

UN 2251 3/PG 2

WGK Germany 

2

RTECS 

RB6535000

F 

13

Autoignition Temperature

350 °C

TSCA 

Yes

HazardClass 

3

PackingGroup 

II

HS Code 

29021990

Toxicity

LD50 orl-rat: 890 mg/kg SHELL*

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H225Highly Flammable liquid and vapour

Precautionary statements

P210Keep away from heat/sparks/open flames/hot surfaces. — No smoking.

P233Keep container tightly closed.

P240Ground/bond container and receiving equipment.

P241Use explosion-proof electrical/ventilating/lighting/…/equipment.

P242Use only non-sparking tools.

P243Take precautionary measures against static discharge.

2,5-Norbornadiene Chemical Properties,Usage,Production

Chemical Properties

2,5-Norbornadiene, also known as dicycloheptadiene, is a clear colorless to slightly yellow liquid that is soluble in petroleum ether and insoluble in water. Commercially available goods usually contain 500 ppm of 2,6-di-tert-butyl-p-methylphenol (BHT) as a stabilizer. Analyzing the structural characteristics of NBD, it can be found that it has good reaction properties and can synthesize a variety of organic compounds through addition or substitution reactions at the double bond.

Uses

2,5-Norbornadiene is used as an intermediate in prostaglandin synthesis and shows anti-ethylene effect on plants. It acts as a starting material for the synthesis of diamantane and as an acetylene transfer agent for instance, in reaction with 3,6-di-2-pyridyl-1,2,4,5-tetrazine. It is also a useful dienophile in Diels-Alder reactions.

Uses

2,5-Norbornadiene is industrially available as a chemical intermediate. It was not intended for use in perfumes, and it is only occasionally used as such. It serves mainly as a starting material for the manufacture of industrial chemicals, etc.
2,5-Norbornadiene has occasionally been used in Pine needle fragrances to improve the diffusiveness of the fragrance, and to lend initial power and short life to the fragrances which are intended for "short-effect" purposes, e.g. dishwashing detergent fragrances, etc. It is also used as a masking agent when a volatile and powerful material is needed at low cost.

Preparation

2,5-Norbornadiene is of interest as a metal-binding ligand, whose complexes are useful for homogeneous catalysis. Norbornadiene can be formed by a Diels-Alder reaction between cyclopentadiene and acetylene.

General Description

2,5-norbornadiene, stabilized appears as a colorless liquid. Insoluble in water and less dense than water. Contact may irritate skin, eyes and mucous membranes. May be toxic by ingestion, inhalation and skin absorption. When heated will polymerize and at decomposition emits acrid smoke and irritating fumes.

Air & Water Reactions

Highly flammable. Insoluble in water.

Reactivity Profile

2,5-NORBORNADIENE may react vigorously with strong oxidizing agents. May react exothermically with reducing agents to release hydrogen gas. In the presence of various catalysts (such as acids) or initiators, may undergo exothermic addition polymerization reactions. Violent explosions at low temperatures in ammonia synthesis gas units have been traced to the addition products of dienes and nitrogen dioxide [Bretherick, 5th Ed., 1995].

Health Hazard

Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.

Safety Profile

Poison by intravenous route. Moderately toxic by ingestion and intraperitoneal routes. Mildly toxic by inhalation. A flammable liquid. When heated to decomposition it emits acrid smoke and irritating fumes.

Purification Methods

Purify the diene by distillation from activated alumina [Landis & Halpern J Am Chem Soc 109 1746 1987]. [Beilstein 5 IV 879.]