Product linearity

Reactions. Mahc acid undergoes many of the characteristic reactions of dibasic acids, monohydric alcohols, and a-hydroxycarboxyUc acids. When heated to 170—180°C, it decomposes to fumaric acid and maleic anhydride which sublimes on further heating (see Maleic anhydride, maleic acid, AND FUMARIC acid). MaUc acid forms two types of condensation products linear malomalic acids and the cycHc dilactone or maUde it does not form an anhydride. 

Because this diketene acetal is so susceptible to cationic polymerization, acids cannot be used to catalyze its condensation with diols because the competing cationic polymerization of the diketene acetal double bonds leads to a crosslinked product. Linear polymers can, however, be prepared by using iodine in pyridine (11). Polymer structure was verified by 13c nmR spectroscopy as shown in Fig. 

The fact that universal Brondsted-Evans-Polanyi relations appear to exist for these dissociation reactions raises the following questions. Why is the relationship between the activation energy and the adsorption energy of the dissociation products linear Why does it depend on structure Why is it independent of the adsorbates ... 

Esters and acids from simple carbonylation reactions Alcohols, ethers and esters with higher homologous alkyl groups. Hydrocarbons from hydrogenolysis of the alcohol and its homologs. Ethers from dehydration of the substrate. Esters of the reagent alcohol. s)oiefins from dehydration of the alcohols. Isomeric alcohols. Isomer products (linear/branched 50/50 - 60/40). Only 2-methyl butanol Dimers and trimers of i-butene. 

Acrylic, methacrylic and but-2-enoic acids react with sulfur tetrafluoride, hydrogen fluoride, and chlorine to afford condensation products, linear chlorofluoro ethers, and chlorofluoroalkanes. For example, the reaction of acrylic acid (15).242... 

No studies were located that specifically address white phosphorus metabolism in humans after oral exposure. However, since orthophosphate is a stable end-product of the inorganic oxidation and hydrolysis of white phosphorus, it is appropriate to examine data on serum phosphate levels in humans following oral ingestion of white phosphorus (these data are discussed further in Section 2.2). Although orthophosphate is the stable end-product, linear and cyclic phosphorus compounds do exist that are stable for relatively long periods, and these may be metabolic blockers especially where phosphorus metabolism is on-going. 

A key issue in the hydroformylation reaction is the ratio of normal to iso product (linear and branched product) produced. Figure 6.1 explains this colloquial expression. The linear product is the desired product, since the value of butanal is higher also because this is the product which can be converted to... 

The linearity of the aldehyde product increases with the concentration of triphenyl phosphine. This is being exploited in the Union Carbide process for the hydroformylation of propene in which linearities >90% are obtained. The rate, however, drops to lower values and the most likely explanation for the higher linearities in this system would seem to be the steric congestion around the rhodium atom at high phosphine concentrations, which kinetically and thermodynamically favours the formation of linear alkyl rhodium complexes relative to branched alkyl rhodium complexes. Product linearity decreases with the number of triphenyl phosphines present in the series of precursor complexes ... 

Based on the entropy production, linear phenomenological equations for an isothermal flow of substance / become... 

The main advantage of this convenient two-step process is avoiding the unpleasant odor of the dithiols, whereas the yields of the resulting macrocycles are lower than in the above-mentioned general procedure. With only one exception (37%), yields do not exceed 25%. As for the side products, linear polymeric sulfides occur. Only by varying the alkali metal of the hydroxide, the result of the reaction can be influenced. Using cesium instead of sodium hydroxide, the 1 1 ratio product is nearly completely suppressed (2% compared to 8%) and the yield of the 2 2 ratio product is elevated from 14% to 17%. Furthermore, the 3 3 ratio product (3X)S6 is generated, as a third macrocycle, with a yield of 5%. 

The regioselectivity in the hydroformylation of monohydroxyben-zenes was the same for the host catalyst and a triphenylphosphine complex of rhodium (with a molar product ratio linear branched = 2 1) (35). No isomerization was observed. Rates of the conversion of monohydrox-ybenzenes when host-guest catalysis is employed are lower than when a triphenylphosphine complex of rhodium is used. In contrast, dihydroxy substrates, which are more strongly boimd to the host, react at higher rates, with an initial increase by a factor of 4 relative to catalysis by the bare rhodium complex. Dihydroxybenzenes also gave the selectivities to linear products (linear branched molar product ratio > 20 1, see below). At 30% conversion, product inhibition took place. 

In vinyl polymerization, there is no mechanism available to bring the system to the thermodynamic equilibrium, thus only the kinetic product, linear polymer, is formed. 

The catalyst has some isomerisation activity so the product linear olefins can have the double bond in any position, similarly any linear isomer can be used as a feedstock. Branched olefins (e.g. isobutene) are not usually converted. 

From a steric viewpoint, the considerably bulkier trialkylphosphine ligand should, and does, favor formation of linear products. While linear to branched ratios of only 2-3 1 are typically found for HCo(CO)4, higher regioselectivities of 7-8 1 occur for HCo(CO)3(PR3). There is a phosphine Cone Angle cutoff at about 132°, after which the steric effects of the phosphine ligand do not increase the product linear regioselectivity any further. 

The nickel concentration in the catalyst system is in the range 0.001-0.005 mol %. The oligomerization is carried out in a series of reactors at temperatures of 80-140 °C and pressures of 7-14 MPa. The rate of the reaction is controlled by the rate of catalyst addition [38]. A high partial pressure of ethylene is required to obtain good reaction rates and high product linearity [30]. The linear a-olefins produced are obtained in a Schulz-Flory type of distribution with up to 99% linearity and 96-98 % terminal olefins over the whole range from C4 to C30+ (cf Table 4) [21]. 

A significant reduction in tetralin content was brought about by the conversion of diolefins to mono-olefins prior to alkylation. Product linearity is a parameter related to the rate of biodegradation of the ultimate LAS product. The 2-phenyl content of the LAB has an impact on product solubility with a maximum solubility at approximately 30%. As can be seen in Table 3, the Detal LAB has the same or better linearity, improved sulfonate color, and lower tetralin content compared to the LAB produced in either the AICI3 or the HF alkylation process. It also has higher 2-phenylalkane content, which gives improved solubility... 

Marcomini, A., F.Fdipuzzi, and W.Giger. 1988a. Aromatic surfactants in detergent cleaning products linear aUcylbenzenesulphonates and alkylphenol polyethoxylates. Chemosphere. 17 853-863. 

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