Patent GB-737124-A (GB)
Title: Complex compounds of iron carbonyl and a cyclopentadiene and their use in fuels and lubricating compositions
Inventor: LEEDHAM KENNETH
IPC: C10L1/30
Filed: 1953-03-20
Abstract: An iron carbonyl and a cyclopentadiene are reacted in the liquid phase at elevated temperatures to give a complex compound of formula Fe2(CO)3R2, where R represents a substituted or unsubstituted cyclopentadienyl group.  Suitable substituted cyclopentadienes specified include the 2-methyl-4-ethyl-, 1-methyl-3-ethyl-, 1 - methyl - 3 - isopropyl -, 1 - isopropyl - 3 - methyl -, 1,2,3,4 - tetraphenyl -, 1,2,4 - triphenyl -, 1 - methyl - 2,3,5 - triphenyl -, 1,4 - dimethyl - 2,3,5 - triphenyl -, 1,4 - diphenyl - cyclopentadienes, and the 5-alkyl-cyclopentadienes (e.g. 5-isopropyl- and 5-sec.-butyl-) prepared by reduction of the fulvenes.  The reaction may be carried out under pressure at a temperature between 100 DEG  and 200 DEG  C., preferably in the absence of oxygen.  The products may be used as additives for lubricating oil compositions and as anti-knock agents (see Group III).  They are also intermediates in the production of iron cyclopentadienes, which may be prepared by heating the carbonyl complex, preferably in an inert atmosphere, to a temperature above its decomposition temperature but below the decomposition temperature of the desired product, e.g. between 150 DEG -300 DEG  C.  In an example iron pentacarbonyl and cyclopentadiene are heated in an autoclave in an atmosphere of nitrogen  The reaction mixture is washed with ether and recrystallised from petroleum spirit.  A further example (4) describes the conversion of the complex so obtained to dicyclopentadienyl iron by heating in an autoclave at 0.1 mm. pressure to 220 DEG  C., extracting the product with acetone and steam distilling.ALSO:A minor proportion of a complex compound of an iron carbonyl and a substituted or unsubstituted cyclopentadiene of formula Fe2(CO)3R2, where R represents the cyclopentadienyl radical (see Group IV (b)) is added to liquid fuels comprising hydrocarbons boiling in the gasoline boiling range or to lubricating oils. Substituted cyclopentadienes include the 2-methyl-4-ethyl-, 1-methyl-3-ethyl-, 1-methyl-3 - isopropyl-, 1 - isopropyl - 3 - methyl-, 1,2,3,4 - tetraphenyl-, 1,2,4 - triphenyl-, 1 - methyl - 2,3,5 - triphenyl-, 1,4 - dimethyl - 2,3,5 - triphenyl-, 1,4 - diphenyl-, and the 5 - alkyl-derivatives (e.g. 5-isopropyl- and 5-sec.-butyl-) prepared by reduction of the fulvenes.  Liquid fuel compositions may also contain oilsoluble organic compounds containing chlorine, boron, phosphorus, arsenic, silicon, sulphur, selenium or tellurium as scavengers.  A list of suitable compounds for this purpose is given.  They may also include stabilizers and antioxidants such as 2,4-dimethyl-6-tertiary butyl phenol, hydroquinone, 2,6 - di - tertiary butyl-4-methyl phenol, N - phenyl - a  - naphthylamine and N,N1-dibutyl-p-phenylenediamine.  Additional anti-knock additives such as iron carbonyl, amines (monomethylaniline), tetraethyl lead, ethyl-trimethyl lead, diethyl-di-methyl lead, triethyl-methyl lead and tetramethyl lead.  The fuel may be a straight run or catalytically cracked gasoline, and it may be blended with aromatic hydrocarbons (benzene, toluene) or with volatile alcohols or ethers. The complex compound may be added to the fuel in amounts of between 0.1 and 15 grams per gallon, depending on the fuel and the desired octane rating.  In an example (3) a complex prepared from iron pentacarbonyl and cyclopentadiene of empirical formula Fe2C13H10O3\t is added in amounts of 1.15 grams per litre to a blend of a catalytically cracked gasoline and a straight run gasoline.  The octane number is increased from 89.1 to 92.1.  Lubricating oil compositions may contain from 0.01 to 5.0 per cent by weight of the complex compound.  The lubricating oil may be a petroleum mineral oil, and it may be refined by treatment with sulphuric acid, clay or by solvent extraction.  Synthetic lubricating oils such as polymerized olefins and alkylated aromatics (e.g. polytertiary butyl naphthalenes) or mixtures of these oils with mineral oils may form the oil base of the composition.  Antioxidants (aromatic amines, alkylated phenols, aminophenols), corrosion inhibitors (partial fatty acid esters of polyhydric alcohols and alkyl substituted succinic acids) detergents (metal soaps of fatty acids, naphthenic acids or hydroxy aromatic carboxylic acids) pour-point depressants, anti-foam agents and viscosity index improvers may also be included in the compositions.  Specifications 722,538, [Group IV (b)], and 737,092 are referred to.