cover image

Methylcyclopentadienyl manganese tricarbonyl

Chemical compound / From Wikipedia, the free encyclopedia

Dear Wikiwand AI, let's keep it short by simply answering these key questions:

Can you list the top facts and stats about Methylcyclopentadienyl manganese tricarbonyl?

Summarize this article for a 10 years old

SHOW ALL QUESTIONS

Methylcyclopentadienyl manganese tricarbonyl (MMT or MCMT) is an organomanganese compound with the formula (C5H4CH3)Mn(CO)3. Initially marketed as a supplement for use in leaded gasoline, MMT was later used in unleaded gasoline to increase the octane rating. Following the implementation of the Clean Air Act (United States) (CAA) in 1970, MMT continued to be used alongside tetraethyl lead (TEL) in the US as leaded gasoline was phased out (prior to TEL finally being banned from US gasoline in 1995), and was also used in unleaded gasoline until 1977. Ethyl Corporation obtained a waiver from the U.S. EPA (Environmental Protection Agency) in 1995, which allows the use of MMT in US unleaded gasoline (not including reformulated gasoline) at a treat rate equivalent to 8.3 mg Mn/L (manganese per liter).[2]

Quick facts: Names, Identifiers, Properties, Structure, Ha... ▼
Methylcyclopentadienyl manganese tricarbonyl
Methylcyclopentadienyl-Manganese-Tricarbonyl_Skeletal.svg
MMT-3D-balls.png
Names
IUPAC name
tricarbonyl(methyl-η5-cyclopentadienyl)manganese
Other names
MMT, CI-2, Combustion Improver-2, Manganese tricarbonylmethylcyclopentadienyl, 2-Methylcyclopentadienyl manganese tricarbonyl
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.031.957 Edit this at Wikidata
EC Number
  • 235-166-5
RTECS number
  • OP1450000
UNII
UN number 3281
  • InChI=1S/C6H7.3CO.Mn/c1-6-4-2-3-5-6;3*1-2;/h2-5H,1H3;;;;/q-1;;;;
    Key: IYSGJCJSRBFZSZ-UHFFFAOYSA-N
  • CC1=C[CH-]C=C1.[C-]#[O+].[C-]#[O+].[C-]#[O+].[Mn]
Properties
C9H7MnO3
Molar mass 218.09 g/mol
Appearance pale yellow to dark orange liquid[1]
Odor faint, pleasant[1]
Density 1.38 g/cm3
Melting point −1 °C (30 °F; 272 K)
Boiling point 232 to 233 °C (450 to 451 °F; 505 to 506 K)
low[vague]
Solubility Hydrocarbons (petrol), ether, alcohol, THF
Vapor pressure 7 mmHg (100°C)[1]
Structure
Tetrahedral at Mn
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Flammable, toxic
GHS labelling:
GHS06: ToxicGHS09: Environmental hazard
Danger
H301, H310, H315, H330, H372, H410
P260, P273, P280, P284, P301+P310, P302+P350
Flash point 110 °C; 230 °F; 383 K[1]
NIOSH (US health exposure limits):
PEL (Permissible)
 C 5 mg/m3[1]
REL (Recommended)
 TWA 0.2 mg/m3 [skin][1]
IDLH (Immediate danger)
 N.D.[1]
Related compounds
Related compounds
 ferrocene
Mn2(CO)10
dicyclopentadiene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)
Close ▲

MMT has been used in Canadian gasoline since 1976 (and in numerous other countries for many years) at a concentration up to 8.3 mg Mn/L (though the importation and interprovincial trade of gasoline containing MMT was restricted briefly during the period 1997–1998)[3][4] and was introduced into Australia in 2000. It has been sold under the tradenames HiTEC 3000, Cestoburn and Ecotane.[5][6] MMT is also used in China.[7]