2,2,4-Trimethylpentane CAS#540-84-1
Excellent Anti-Knock Performance – 2,2,4-Trimethylpentane (isooctane) has an octane rating of 100, making it an important standard anti-knock agent for gasoline applications.
High-Octane Gasoline Additive – With its high octane rating, isooctane is widely used as a gasoline additive to improve fuel performance.
Reliable Octane Reference Standard – Isooctane serves as a reference substance for determining and evaluating gasoline octane ratings.
Good Organic Solubility – Isooctane is insoluble in water but readily soluble in organic solvents such as diethyl ether, benzene, and acetone, supporting its use in various chemical applications.
Products Description of 2,2,4-Trimethylpentane CAS#540-84-1
2,2,4-Trimethylpentane, commonly known as isooctane, is a standard anti-knock agent with an octane rating of 100. Its chemical formula is C₈H₁₈, and its CAS number is 540-84-1. It has a melting point of −107.4°C and a boiling point of 98–99°C.
Isooctane is a colorless liquid with a high octane rating and is widely used as a gasoline additive. It also serves as a reference substance for determining gasoline octane ratings. Isooctane is insoluble in water but soluble in a variety of organic solvents, including diethyl ether, benzene, and acetone.
2,2,4-Trimethylpentane Chemical Properties
| Melting point | -107 °C |
| Boiling point | 98-99 °C(lit.) |
| density | 0.692 g/mL at 25 °C(lit.) |
| vapor density | 3.9 (vs air) |
| vapor pressure | 41 mm Hg ( 21 °C) |
| refractive index | n20/D 1.391(lit.) |
| Fp | 18 °F |
| storage temp. | Store at +5°C to +30°C. |
| solubility | water: insoluble |
| form | Liquid |
| pka | >14 (Schwarzenbach et al., 1993) |
| Specific Gravity | 0.692 (20/4℃) |
| color | APHA: ≤10 |
| Relative polarity | -0.4 |
| explosive limit | 1%(V) |
| Odor Threshold | 0.11ppm |
| Water Solubility | INSOLUBLE |
| FreezingPoint | -107.52℃ |
| λmax | λ: 205 nm Amax: 1.00 |
| λ: 225 nm Amax: 0.10 | |
| λ: 254 nm Amax: 0.01 | |
| Merck | 145193 |
| BRN | 1696876 |
| Henry's Law Constant | 3.23 at 25 °C (Mackay and Shiu, 1981) |
| Exposure limits | ACGIH TLV: TWA for all isomers 300 ppm (adopted). |
| Dielectric constant | 2.1（Ambient） |
| Stability: | Stable. Highly flammable. Incompatible with oxidizing agents, reducing agents. |
| LogP | 4.373 (est) |
| CAS DataBase Reference | 540-84-1(CAS DataBase Reference) |
| NIST Chemistry Reference | Pentane, 2,2,4-trimethyl-(540-84-1) |
| EPA Substance Registry System | 2,2,4-Trimethylpentane (540-84-1) |
| Hazard Codes | F,Xn,N |
| Risk Statements | 11-38-50/53-65-67 |
| Safety Statements | 9-16-29-33-60-61-62 |
| RIDADR | UN 1262 3/PG 2 |
| WGK Germany | 1 |
| RTECS | SA3320000 |
| Autoignition Temperature | 745 °F |
| TSCA | Yes |
| HS Code | 2901 10 00 |
| HazardClass | 3 |
| PackingGroup | II |
| Hazardous Substances Data | 540-84-1(Hazardous Substances Data) |
| Toxicity | LD50 orally in Rabbit: > 2500 mg/kg |
