Carbon from acetylene

Write a series of equations showing how to prepare cis 5 decene from acetylene and 1 bromobutane as the source of all its carbons using any nec essary organic or inorganic reagents Hint You may find it helpful to review Sec tion 9 6)... 

In the United States butadiene was prepared initially from ethanol and later by cracking four-carbon hydrocarbon streams (see Butadiene). In Germany butadiene was prepared from acetylene via the following steps acetylene — acetaldehyde — 3-hydroxybutyraldehyde — 1,3-butanediol — ... 

The stoichiometric and the catalytic reactions occur simultaneously, but the catalytic reaction predominates. The process is started with stoichiometric amounts, but afterward, carbon monoxide, acetylene, and excess alcohol give most of the acrylate ester by the catalytic reaction. The nickel chloride is recovered and recycled to the nickel carbonyl synthesis step. The main by-product is ethyl propionate, which is difficult to separate from ethyl acrylate. However, by proper control of the feeds and reaction conditions, it is possible to keep the ethyl propionate content below 1%. Even so, this is significantly higher than the propionate content of the esters from the propylene oxidation route. 

The concentration of is determined by measurement of the specific P-activity. Usually, the carbon from the sample is converted into a gas, eg, carbon dioxide, methane, or acetylene, and introduced into a gas-proportional counter. Alternatively, Hquid-scintiHation counting is used after a benzene synthesis. The limit of the technique, ca 50,000 yr, is determined largely by the signal to background ratio and counting statistics. 

Polymerization and GycliZation. Acetylene polymerizes at elevated temperatures and pressures which do not exceed the explosive decomposition point. Beyond this point, acetylene explosively decomposes to carbon and hydrogen. At 600—700°C and atmospheric pressure, benzene and other aromatics are formed from acetylene on heavy-metal catalysts. 

A number of processes have been used to produce carbon black including the oil-furnace, impingement (channel), lampblack, and the thermal decomposition of natural gas and acetjiene (3). These processes produce different grades of carbon and are referred to by the process by which they are made, eg, oil-furnace black, lampblack, thermal black, acetylene black, and channel-type impingement black. A small amount of by-product carbon from the manufacture of synthesis gas from Hquid hydrocarbons has found appHcations in electrically conductive compositions. The different grades from the various processes have certain unique characteristics, but it is now possible to produce reasonable approximations of most of these grades by the od-fumace process. Since over 95% of the total output of carbon black is produced by the od-fumace process, this article emphasizes this process. 

Tetrachloroethylene was first prepared ia 1821 by Faraday by thermal decomposition of hexachloroethane. Tetrachloroethylene is typically produced as a coproduct with either trichloroethylene or carbon tetrachloride from hydrocarbons, partially chloriaated hydrocarbons, and chlorine. Although production of tetrachloroethylene and trichloroethylene from acetylene was once the dominant process, it is now obsolete because of the high cost of acetylene. Demand for tetrachloroethylene peaked ia the 1980s. The decline ia demand can be attributed to use of tighter equipment and solvent recovery ia the dry-cleaning and metal cleaning iadustries and the phaseout of CFG 113 (trichlorotrifluoroethane) under the Montreal Protocol. 

How would you synthesize the following compounds from acetylene and any alkyl halides with four or fewer carbons More than one step may be required. 

Titanium-acetylene complexes 29 generated in situ from acetylenes, Ti(0-i-Pr)4 and /-PrMgX react with imines to form azatitanacyclopentenes 30 which then react with carbon monoxide under atmospheric pressure to provide pyrroles 31 <96TL7787>. This reaction, which utilizes commercially available reagents is an improvement over a related procedure via the corresponding zirconium complexes under 1500 psi CO <89JA776>. 

Highly stabilized phosphorus ylides are prepared from acetylenic esters, a carbon-based nucleophile, and triphenylphosphine in aqueous media.40 In acetone-water (2 1) solvent, the reaction proceeds via the conjugate addition of triphenylphosphine to dialkyl acetylenedicarboxy-lates the resulting vinyl triphenylphosphonium salts undergo Michael addition reaction with a carbon-nucleophile to give the corresponding highly stabilized phosphorus ylides. 

These reactions do not occur at lower temperatures because of activation energy barriers and because H2 becomes the dominant form of hydrogen. Aromatic species are produced initially from acetylene via Diels-Alder type processes, in which a two-carbon and a four-carbon hydrocarbon condense into an aromatic species. Once PAHs are synthesized, they may continue to grow to form carbonaceous small grains. 

The air gas-diffusion electrode developed in this laboratory [5] is a double-layer tablet (thickness ca.1.5 mm), which separates the electrolyte in the cell from the surrounding air. The electrode comprises two layers a porous, from highly hydrophobic, electrically conductive gas layer (from the side of the air) and a catalytic layer (from the side of the electrolyte). The gas layer consists of a carbon-based hydrophobic material produced from acetylene black and PTFE by a special technology [6], The high porosity of the gas layer ensures effective oxygen supply into the reaction zone of the electrode simultaneously the leakage of the electrolyte through the electrode... 

Acetylene Black A process for making carbon black from acetylene by thermal decomposition at 800 to 1,000°C in refractory-lined, water-cooled retorts. 

Reppe A family of processes for making a range of aliphatic compounds from acetylene, developed by W. Reppe in IG Farbenindustrie, Germany, before and during World War II. In one of the processes, acetylene is reacted with carbon monoxide to yield acrylic acid CH=CH + CO + H20 CH2=CH-COOH Acrylic esters are formed if alcohols are used instead of water ... 

North American producers of, 7 129t physical properties of, 7.T15-117 5 29t production from acetaldehyde, 7 102, 111 production from acetylene, 7 219 production from carbon monoxide, 5 4-5 production of, 76 299 24 265... 

The assignment of the monomer solution spectrum was performed by using an NMR spectral database system (SDBS-NMR)54. The signals of the six acetylene carbons from 60.34 to 81.91 ppm in the solution spectrum indicated the monomer structure of a dodec-ahexyne derivative substituted symmetrically by alkyl groups. Since the spectral patterns in Figure 36A are almost the same as those of the monomer, only a small extent of polymerization had occurred during the 30 min after recrystallization. The signal at about... 

Another two-carbon feedstock is acetylene. Acetylene is typically obtained from coal by converting coke calcium carbide and then treating the calcium carbide with water. As shown in Figure 17.3, a number of important monomers can be made from acetylene. Even so, because of the abundance of other feedstocks from petroleum reserves, only some of the routes shown in Figure 17.3 are widely used. 

Metal Hydrides. Metal hydrides generally react readily with acetylenes, often by an insertion mechanism. Cobalt hydrocarbonyl gives complicated mixtures of compounds with acetylenes. The only products which have been identified so far are dicobalt hexacarbonyl acetylene complexes (34). Greenfield reports that, under conditions of the hydroformy lation reaction, acetylenes give only small yields of saturated monoaldehydes (30), probably formed by first hydrogenating the acetylene and then reacting with the olefin. Other workers have identified a variety of products from acetylene, carbon monoxide, and an alcohol with a cobalt catalyst, probably cobalt hydrocarbonyl. The major products observed were succinate esters (74,19) and succinate half ester acetals (19). 

Carbon-filled polymers, especially those made from acetylene black, are fair conductors of heat and electricity. Polymers with fair conductivity have... 

Only seven of the nine carbonyl groups can be liberated as carbon monoxide, indicating that two carbonyl groups have combined with the acetylene to form a new ligand. X-ray studies on the complex derived from acetylene show that the complex contains an unsaturated lactone ring as shown in (LXIII) (160). An important structural feature of (LXIII) is that the... 

A shift from allenes to acetylenic products formed from acetylenic alcohols in which trifluoro-methyl groups are replaced by difluoromethyl groups can be explained in terms of lowering the positive character of the terminal acetylenic carbon atom, thus retarding the nucleophilic attack of fluorine at this position.56... 

Ref la). It is miscible with w, ale and eth (See also Ref 7). Various methods of prepn are given in Refs 1.3 9 In Ref 2 is described the catalytic production of acetaldehyde from acetylene and steam over activated carbon and promoted by phosphoric acid. 

F.CStehling et al, "Carbon Formation from Acetylene." A paper reported in the 6th Symposium on Combustion, Reinhold,... 

Carbon formation from acetylene starts with a reaction such as 3 ... 

The necessity for postulating combination steps raises questions regarding the nature of the intermediates which may be formed from acetylene and then reacted to form carbon. Various types have been suggested, such as aromatics, fulvene-type cyclic compounds, and highly unsaturated aliphatics. There is evidence for formation of all such types in thermal reactions of acetylene, but not enough is known of their chemistry to determine which might be of most significance as an intermediate under combustion conditions. It is probable that no one type actually controls the reaction. Parallel with the chemical question here, there is an important physical question of whether the nucleus for the ultimate carbon particle is a droplet of liquid polymer or a small bit of solid. 

Acrylic acid [79-10-7] - [AIR POLLUTION] (Vol 1) - [ALDEHYDES] (Vol 1) - [ALLYL ALCOHOL AND MONOALLYL DERIVATIVES] (Vol 2) - [MALEIC ANHYDRIDE, MALEIC ACID AND FUMARIC ACID] (Vol 15) - [POLYESTERS, UNSATURATED] (Vol 19) - [FLOCCULATING AGENTS] (Vol 11) - [CARBOXYLICACIDS - SURVEY] (Vol 5) -from acetylene [ACETYLENE-DERIVED CHEMICALS] (Vol 1) -from acrolein [ACROLEIN AND DERIVATIVES] (Vol 1) -acrylic esters from [ACRYLIC ESTER P OLYMERS - SURVEY] (Vol 1) -from carbon monoxide [CARBON MONOXIDE] (Vol 5) -C-21 dicarboxylic acids from piCARBOXYLIC ACIDS] (Vol 8) -decomposition product [MAT. ETC ANHYDRIDE, MALEIC ACID AND FUMARIC ACID] (Vol 15) -economic data [CARBOXYLIC ACIDS - ECONOMIC ASPECTS] (Vol 5) -ethylene copolymers [IONOMERS] (Vol 14) -in floor polishes [POLISHES] (Vol 19) -in manufacture of ion-exchange resins [ION EXCHANGE] (V ol 14) -in methacrylate copolymers [METHACRYLIC POLYMERS] (Vol 16) -in papermaking [PAPERMAKING ADDITIVES] (Vol 18)... 

---