Isopropanol data

Titrimetric analysis is a classical method for generating concentration-time data, especially in second-order reactions. We illustrate with data on the acetylation of isopropanol (reactant B) by acetic anhydride (reactant A), catalyzed by A-methyl-imidazole. The kinetics were followed by hydrolyzing 5.0-ml samples at known times and titrating with standard base. A blank is carried out with the reagents but no alcohol. The reaction is... 

Diketones can be reduced usually in high selectivity to either an intermediate ketol or thediol (72). Selectivity to the ketol depends in large measure on both catalyst and solvent. In cyclohexane solvent, the maximal yield of ketol obtained on partial hydrogenation of biacetyl fell in the order 5% Pd-on-C (99%), 5% Rh-on-C (92%), 5% Pt-on-C (88%), 5% Ru-on-C (63%) from acetylacelone the descending order was 5% Pd-on-C (86%), 5% Rh-on-C (60%), 5% Ru-on-C(35%), 5% Pt-on-C (27%)(56) from 1,4-cyclohexanedione in isopropanol initial selectivity to the ketol fell in the sequence 5% Pd-on-SiO, (96%), 5% Ir-on-C (95%), 5% Ru-on-C (92%), 5% Pt-on-C (67%) (73). Generalizing from these data, it appears palladium is a good first choice to achieve maximal selectivity. 

The frictional pressure drop for liquid flows through micro-channels with diameter ranging from 15 to 150 pm was explored by Judy et al. (2002). Micro-channels fabricated from fused silica and stainless steel were used in these experiments. The measurements were performed with a wide variety of micro-channel diameters, lengths, and types of working fluid (distilled water, methanol, isopropanol), and showed that there were no deviations between the predictions of conventional theory and the experiment. Sharp and Adrian (2004) studied the fluid flow through micro-channels with the diameter ranging from 50 to 247 pm and Reynolds number from 20 to 2,300. Their measurements agree fairly well with theoretical data. 

Two studies have been performed by Littler on the oxidation of cyclohexanol by Hg(II), the second leading to more detailed and reliable data. The reaction is first-order in both oxidant and substrate but the rate is independent of acidity. E is 24.8 kcal.mole AS is 1 eu, Ath/Acd is 3.0 and ko ol HzO 1-30-At 50 °C di-isopropyl ether is attacked at about one-half the rate of isopropanol, which implies that hydride ion abstraction is occurring in both cases. This is supported in the case of cyclohexanol by the isotope effects. 

I were obtained in 10 min for both 20- and 30-mesh grinds. Ten-minute extractions are sufficient to ensure that all additives have been extracted, but it is brief enough that smaller, more volatile additives are not lost. Recovery and precision data for several other additives in II were also reported. Extraction results with microwave heating in isobutanol or isopropanol compared with a 60 min reflux extraction also show good reproducibility (<3 % RSD for all additives analysed). 

Pappas AA, Ackerman BH, Olsen KM, et al. 1991. Isopropanol ingestion A report of 6 episodes with isopropanol and acetone serum concentration time data. Clin Toxicol 21(1) 11-21. 

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 15.19 Physical property data for isopropanol and water.

On the basis of six sets of data on water, two on methanol, and one each on isopropanol and carbon tetrachloride, all falling in the transition region, Ivey obtained the correlation... 

Elkassabgi and Lienhard (1988) provided an extensive subcooled pool boiling CHF data set of 631 observations on cylindical electric resistance heaters ranging from 0.80 to 1.54 mm (0.03 to 0.06 in.) in diameter with four liquids (isopropanol, acetone, methanol, and Freon-113) at atmospheric pressure and up to 140°C (252°F) subcooling. They normalized <7 ritsub data by Sun and Lienhard s (1970) saturated q"Tix SL prediction in terms of B,... 

It is important to point out at this point that the rate constant k and the quantum yield for a photochemical reaction are not fundamentally related. Since the quantum yield depends upon relative rates, the reactivity may be very high (large kr), but if other processes are competing with larger rates, the quantum yield efficiency of the reaction will be very small. That there is no direct correlation between the quantum yield and the rate is clearly seen from the data in Table 1.2 for the photoreduction of some substituted aromatic ketones in isopropanol ... 

To obtain more information on this point, let us examine the data given in Table 3.6<42-47> for some substituted benzophenones. The data in Table 3.6 indicate that benzophenone derivatives having lowest triplet states of n->TT character undergo very efficient photoreduction in isopropyl alcohol. Those derivatives having a lowest it- -it triplet, on the other hand, are only poorly photoreduced, while those having lowest triplets of the charge-transfer type are the least reactive toward photoreduction. In additon, in some cases photoreduction is more efficient in the nonpolar solvent cyclohexane than in isopropanol. This arises from the solvent effect on the transition energies for -> , ir- , and CT transitions discussed in Chapter 1 (see also Table 3.7). 

These three polymeric HALS stabilisers can be detected and positively identified in extracts from polyolefins using an Agilent Ion-trap instrument with positive APCI. Figure 34 shows a chromatogram for a 5-ppm standard of Tinuvin 622 in tetrahydrofuran (THF) and the peak mass spectrum (Figure 35). Similar data for Chimassorb 944 in THF are shown in Figures 36 and 37, respectively. A Waters Xterra C8 150 x 2.00 mm 3 pm 125A column at 60°C with the mobile phase of isopropanol +700 pl/1 hexylamine was employed. 

Fig. 3.36 LDA of the microarray signal patterns measured in a meeting room during night and day. The room temperature was about 22°C in all cases. Data were collected at two meetings a week apart and in the empty room with an isopropanol source at a distance of 0.8 m from KAMINA. The resistances of the sensor segments are normalized by reference and by median. Clearly the air of the empty room with closed and opened windows can be distinguished from the lower air...

The effect of temperature on the RP-HPLC behaviour of /(-carotene isomers has been extensively investigated and the results were employed for the separation of carotenoids of tomato juice extract. Carotenoids were extracted from food samples of 2g by adding magnesium carbonate to the sample and then extracted with methanol-THF (1 1, v/v) in a homogenizer for 5min. The extraction step was repeated twice. The collected supernatants were evaporated to dryness (30°C) and redissolved in methanol-THF (1 1, v/v). Separations were performed on a polymeric ODS column (250 X 4.6 mm i.d. particle size 5/.an). The isocratic mobile phase consisted of methanol-ACN-isopropanol (54 44 2, m/m). The flow-rate was 0.8 or 2.0 ml/min. The effect of temperature on the retention times of lycopene and four /(-carotene isomers is shown in Table 2.11. The data indicated that the temperature exerts a considerable influence on the retention time and separation of /(-carotene isomers. Low temperature enhances the efficacy of separation. 

Inspection of the results in Table 2 shows that the predominant retention of configuration was observed in the cases of isopropanol, cyclopentanol, and cyclohexanol. These preliminary data may be rationalized in terms of the paraUel formation of two sulfurane intermediates (254 and 255), which are responsible for inversion and retention at sulfur, respectively. The relative stabilities of these inter-... 

Very little data exist on the separation efficiency of multilayer diffusion and capillary condensation. Asaeda and Du (1986) used a thin modified alumina membrane to separate alcohol/water gaseous mixtures at high relative pressures (near 1). The azeotropic point could be bypassed for water/ethanol and water/isopropanol mixture by employing eapillary condensation as a separation mechanism at a temperature of 70°C. By deereasing the pore size to the microporous range (pore diameter < 2 nm by plugging the pores with hydroxides), the separation faetors were inereased to above 60 (Asaeda and... 

Based on these findings, new pentacoordinated Ir complexes [lr(cod) (S)-(+)-(NNR )1] were synthesized and characterized also by X-ray crystal structure determination by the same authors (NNR = 2-pyridinal-l-phenyhethylimine, PPEI, 77a 2-acetylpyridine-l-phenylethylimine, APPEl, 77b Scheme 4.32). The complexes were tested in the ATH of ketones in isopropanol and the data compared with results obtained using the corresponding square planar complexes [Ir(cod) (R) -(-)PPE1 ]C104 (76d) [67]. 

Numerous technologically important polymers, for example, many crystalline polyolefins are soluble only at the elevated temperature. Consequently, the high-temperature SEC instruments were designed, in which also dissolution and filtration of samples is performed at elevated temperature. Some SEC eluents such as hexafluoro isopropanol are very expensive, other ones are very aggressive—the extremes represent concentrated sulfuric acid [150] or hexamethyl phosphorotriamide [151] used as the mobile phase for some polyamides or cresols for polyesters [152]. Many biopolymers solicit the appropriate environment (eluent) and/or temperature of experiment below the ambient value to prevent their denaturation. Some polymers rapidly degrade in solution, for example, poly(hydroxy butyrate). These are to be separated as rapidly as possible and the data obtained should be corrected. 

Data obtained from the photoreduction of benzophenone in isopropanol indicates that the quantum yield (for the formation of acetone) is nearly constant using irradiation at several different wavelengths between 366 and 254 mp..16 The quantum yield for phosphorescence emission from the carbonyl n,ir triplet state is independent of exciting wavelength.22 Furthermore, the singlet excitation spectrum for the phosphorescence emission has been found to be very similar (if not identical) to the absorption spectrum.23 There are other examples where irradiation in the region of a given transition has ultimately led to a triplet of a different type.24... 

Figure 20 illustrates the H-plot constructed from the data for PHPG in aqueous methanol (50). The prediction is quite well borne out by experimental data. The values of a0 and ay derived from the intercept and slope of the indicated line are given in Table 2. Similar results were obtained for PBLG in the CHL-DCA mixture (49), though the H-plot scattered more than in Fig. 20. For the system PHEG-aqueous isopropanol the values of a were a) large that the approximate expressions for Hz and H3 were not applicable. Therefore the data for this system were analyzed with the H2 and H3 computed from Nagai s original expression for (5/). The resulting values of a0 and ax are given in Table 2.

Aristov, V.N., Redkin, Ju. V, Bruskin, Z.Z. Ogelznev, G.A. (1981) Experimental data on the mutagenic action of toluene, isopropanol and sulfur dioxide. Gig. Tr. prof. Zabol., 33-36 Arnold, G.L., Kirby, R.S., Langendoerfer, S. Wilkins-Haug, L. (1994) Toluene embryopathy ... 

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