Water 1-propanol, 210 Table

The nitro alcohols in Table 1 are manufactured in commercial quantities however, three of the five of them are used only for the production of the corresponding amino alcohols. 2-Methyl-2-nitro-l-propanol (NMP) is available as the crystalline soHd or as a mixture with siHcon dioxide. 2-Hydroxymethyl-2-nitro-1,3-propanediol is available as the soHd ( 9.15/kg), a 50% solution in water ( 2.33/kg), a 25% solution in water ( 1.41/kg), or as... 

Propylene oxide is a colorless, low hoiling (34.2°C) liquid. Table 1 lists general physical properties Table 2 provides equations for temperature variation on some thermodynamic functions. Vapor—liquid equilibrium data for binary mixtures of propylene oxide and other chemicals of commercial importance ate available. References for binary mixtures include 1,2-propanediol (14), water (7,8,15), 1,2-dichloropropane [78-87-5] (16), 2-propanol [67-63-0] (17), 2-methyl-2-pentene [625-27-4] (18), methyl formate [107-31-3] (19), acetaldehyde [75-07-0] (17), methanol [67-56-1] (20), ptopanal [123-38-6] (16), 1-phenylethanol [60-12-8] (21), and / /f-butanol [75-65-0] (22,23). 

Table 5. Strategic Separations for 2-Propanol-Water System...

For a binary system, the two possible opportunistic distillations are essentially identical and can be combined to concentrate the feed up to about 68% 2-propanol and produce pure water. The feed and products of the two possible strategic separations are ill-defined, whereas those of the opportunistic separation are known as outlined in Table 6. 

International Specialty Products (ISP) suppHes ethyl, isopropyl, and -butyl half-esters of PMVEMA as 50% solutions in ethanol or 2-propanol. Typical properties are shown in Table 8. These half-esters do not dissolve in water but are soluble in dilute aqueous alkaU and in aqueous alcohoHc amine solutions. The main appHcation for the half-esters is in hairsprays where they combine excellent hair-holding properties at high humidity without making the hair stiff or harsh. These half-esters are easily removed during shampooing, have a very low order of toxicity, and form tack-free films that exhibit good gloss, luster, and sheen (see Hair preparations). 

Table 2 gives physical property data for propylene chlorohydrins. 2-Chloro-l-propanol [78-89-7] HOCH2CHCICH2, is also named 2-propylene chlorohydrin, 2-chloropropyl alcohol, or 2-chloro-l-hydroxypropane. l-Chloro-2-propanol [127-00-4] CICH2CHOHCH2, also known as j -propjlene chlorohydrin, 1-chloroisopropyl alcohol, and l-chloro-2-hydroxypropane, is a colorless Hquid, miscible in water, ethanol, and ethyl ether. 

One of the first examples of the application of reverse-phase liquid chromatography-gas chromatography for this type of analysis was applied to atrazine (98). This method used a loop-type interface. The mobile phase was the most important parameter because retention in the LC column must be sufficient (there must be a high percentage of water), although a low percentage of water is only possible when the loop-type interface is used to transfer the LC fraction. The authors solved this problem by using methanol/water (60 40) with 5% 1-propanol and a precolumn. The experimental conditions employed are shown in Table 13.2. 

Various amines find application for pH control. The most commonly used are ammonia, morpholine, cyclohexylamine, and, more recently AMP (2-amino-2-methyl-l-propanol). The amount of each needed to produce a given pH depends upon the basicity constant, and values of this are given in Table 17.4. The volatility also influences their utility and their selection for any particular application. Like other substances, amines tend towards equilibrium concentrations in each phase of the steam/water mixture, the equilibrium being temperature dependent. Values of the distribution coefficient, Kp, are also given in Table 17.4. These factors need to be taken into account when estimating the pH attainable at any given point in a circuit so as to provide appropriate protection for each location. 

In some cases, these organic solvents cause no stronger folding but adversely (Lys-Gly-Pro)n folds to a lower extent in l,l,l,3,3,3-hexafluoro-2-propanol/ethylene glycol or in 1,3-propandiol than in water (Table 3). 

The Diels-Alder reaction of methyl methacrylate with cyclopentadiene was studied [72] with solutions from three different regions of the pseudophase diagram for toluene, water and 2-propanol, in the absence and in the presence of surfactant [sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (HTAB)]. The composition of the three solutions (Table 6.11) corresponds to a W/O-fiE (A), a solution of small aggregates (B) and a normal ternary solution (C). The diastereoselectivity was practically constant in the absence and in the presence of surfactant a slight increase of endo adduct was observed in the C medium in the presence of surfactant. This suggests that the reaction probably occurs in the interphase and that the transition state has a similar environment in all three media. 

Example 4.5 2-Propanol (isopropanol) and water form an azeotropic mixture at a particular liquid composition that results in the vapor and liquid compositions being equal. Vapor-liquid equilibrium for 2-propanol-water mixtures can be predicted by the Wilson equation. Vapor pressure coefficients in bar with temperature in Kelvin for the Antoine equation are given in Table 4.113. Data for the Wilson equation are given in Table 4.126. Assume the gas constant R = 8.3145 kJ-kmol 1-K 1. Determine the azeotropic composition at 1 atm. 

Table 4.12 Data for 2-propanol (1) and water (2) for the Wilson equation at 1 atm6.

Thus, if the saturated vapor pressure is known at the azeotropic composition, the activity coefficient can be calculated. If the composition of the azeotrope is known, then the compositions and activity of the coefficients at the azeotrope can be substituted into the Wilson equation to determine the interaction parameters. For the 2-propanol-water system, the azeotropic composition of 2-propanol can be assumed to be at a mole fraction of 0.69 and temperature of 353.4 K at 1 atm. By combining Equation 4.93 with the Wilson equation for a binary system, set up two simultaneous equations and solve Au and A21. Vapor pressure data can be taken from Table 4.11 and the universal gas constant can be taken to be 8.3145 kJ-kmol 1-K 1. Then, using the values of molar volume in Table 4.12, calculate the interaction parameters for the Wilson equation and compare with the values in Table 4.12. 

Recently, an example of cycloamylose-induced catalysis has been presented which may be attributed, in part, to a favorable conformational effect. The rates of decarboxylation of several unionized /3-keto acids are accelerated approximately six-fold by cycloheptaamylose (Table XV) (Straub and Bender, 1972). Unlike anionic decarboxylations, the rates of acidic decarboxylations are not highly solvent dependent. Relative to water, for example, the rate of decarboxylation of benzoylacetic acid is accelerated by a maximum of 2.5-fold in mixed 2-propanol-water solutions.6 Thus, if it is assumed that 2-propanol-water solutions accurately simulate the properties of the cycloamylose cavity, the observed rate accelerations cannot be attributed solely to a microsolvent effect. Since decarboxylations of unionized /3-keto acids proceed through a cyclic transition state (Scheme X), Straub and Bender suggested that an additional rate acceleration may be derived from preferential inclusion of the cyclic ground state conformer. This process effectively freezes the substrate in a reactive conformation and, in this case, complements the microsolvent effect. 

Table 6.6 lists some reactions of the electron in water, ammonia, and alcohols. These are not exhaustive, but have been chosen for the sake of analyzing reaction mechanisms. Only three alcohols—methanol, ethanol, and 2-propanol—are included where intercomparison can be effected. On the theoretical side, Marcus (1965a, b) applied his electron transfer concept (Marcus, 1964) to reactions of es. The Russian school simultaneously pursued the topic vigorously (Levich, 1966 Dogonadze et al, 1969 Dogonadze, 1971 Vorotyntsev et al, 1970 see also Schmidt, 1973). Kestner and Logan (1972) pointed out the similarity between the Marcus theory and the theories of the Russian school. The experimental features of eh reactions have been detailed by Hart and Anbar (1970), and a review of various es reactions has been presented by Matheson (1975). Bolton and Freeman (1976) have discussed solvent effects on es reaction rates in water and in alcohols. 

Transition-metal catalysts are, in general, more active than the MPVO catalysts in the reduction of ketones via hydrogen transfer. Especially, upon the introduction of a small amount of base into the reaction mixture, TOFs of transition-metal catalysts are typically five- to 10-fold higher than those of MPVO catalysts (see Table 20.7, MPVO catalysts entries 1-20, transition-metal catalysts entries 21-53). The transition-metal catalysts are less sensitive to moisture than MPVO catalysts. Transition metal-catalyzed reactions are frequently carried out in 2-propanol/water mixtures. Successful transition-metal catalysts for transfer hydrogenations are based not only on iridium, rhodium or ruthenium ions but also on nickel [93], rhenium [94] and osmium [95]. It has been reported that... 

The minimum amount of catalyst needed to obtain maximum selectivity was determined to be 5 mol%. Larger quantities had no effect. Consistent with other literature reports[17], very small quantities of water (5 mol% = 2.5 mg E O/g 3) lowered the selectivities (Table 11.6, entry 4). Water sensitivity required thorough drying of the equipment, the starting materials and the solvents. In the case of tetrahydrofuran, drying was achieved by using activated 5 A molecular sieves (KF titration >0.005%). On the other hand, solvents used for crystallization of the starting material (3), such as 2-propanol and acetonitrile showed little effect on the enantioselectivities of the reaction (entries 6 and 7). 

A representative selection of the polymerisations described above were terminated with tritiated water, and one of them with 14C-labelled 2-propanol, and the polymers were worked up and assayed as described in the Experimental Part the number of tritium atoms per polymer molecule is shown in Table 1. 

Table 1 Details of polymerisations killed with tritiated water or 14C-labelled 2-propanol...

Normal-phase HPLC has also found application in the analysis of pigments in marine sediments and water-column particulate matter. Sediments were extracted twice with methanol and twice with dichloromethane. The combined extracts were washed with water, concentrated under vacuum and redissolved in acetone. Nomal-phase separation was performed with gradient elution solvents A and B being hexane-N,N-disopropylethylamine (99.5 0.5, v/v) and hexane-2-propanol (60 40, v/v), respectively. Gradient conditions were 100 per cent A, in 0 min 50 per cent A, in 10 min 0 per cent A in 15 min isocratic, 20 min. Preparative RP-HPLC was carried out in an ODS column (100 X 4.6 mm i.d. particle size 3 jum). Solvent A was methanol-aqueous 0.5 N ammonium acetate (75 25, v/v), solvent B methanol-acetone (20 80, v/v). The gradient was as follows 0 min, 60 per cent A 40 per cent A over 2 min 0 per cent A over 28 min isocratic, 30 min. The same column and mobile phase components were applied for the analytical separation of solutes. The chemical structure and retention time of the major pigments are compiled in Table 2.96. 

Various liquid chromatographic techniques have been frequently employed for the purification of commercial dyes for theoretical studies or for the exact determination of their toxicity and environmental pollution capacity. Thus, several sulphonated azo dyes were purified by using reversed-phase preparative HPLC. The chemical strctures, colour index names and numbers, and molecular masses of the sulphonated azo dyes included in the experiments are listed in Fig. 3.114. In order to determine the non-sulphonated azo dyes impurities, commercial dye samples were extracted with hexane, chloroform and ethyl acetate. Colourization of the organic phase indicated impurities. TLC carried out on silica and ODS stationary phases was also applied to control impurities. Mobile phases were composed of methanol, chloroform, acetone, ACN, 2-propanol, water and 0.1 M sodium sulphate depending on the type of stationary phase. Two ODS columns were employed for the analytical separation of dyes. The parameters of the columns were 150 X 3.9 mm i.d. particle size 4 /jm and 250 X 4.6 mm i.d. particle size 5 //m. Mobile phases consisted of methanol and 0.05 M aqueous ammonium acetate in various volume ratios. The flow rate was 0.9 ml/min and dyes were detected at 254 nm. Preparative separations were carried out in an ODS column (250 X 21.2 mm i.d.) using a flow rate of 13.5 ml/min. The composition of the mobile phases employed for the analytical and preparative separation of dyes is compiled in Table 3.33. 

The processes that constitute life take place in water (there may be a few exceptions but never mind). There are many substances characteristic of life, both simple molecules and highly complex ones, which interact readily with water. Common examples include sucrose, table salt, ethanol, rubbing alcohol (isopropyl alcohol or 2-propanol), and cotton, for example. Such substances are hydrophilic. As we shall see, most hydrophihc substances have a structural element in common with water. This fact is frequently captured in the idea like likes like. ... 

Ion exchange chromatography at pH 5.25 of the aqueous fractions yielded six peaks, I - VI (fig. 1). Peak V contained a mixture of amino acids (TLC with n-propanol/ammonia/water = 8 1 11 by vol.) (table 1). Therefore, the pooled fractions of V were separated at pH 3.5 (fig. 2). Three peaks were observed, the first probably representing ammonia formed from azide. The second peak (V-1) still displayed a minor impurity on TLC, whereas the third peak (V-2) appeared as a single spot. Peak V-1 could not be separated further by ion exchange chromatography at pH 7.0 (peak V-1-1). 

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