Acetonitrile comparative tables

Vreactor=70 ml VCh=Vrcn=10 ml (0.045 mole) 111 1 =0.3 g PH2=80 bar (at RT) was not maintained during reaction NH3/RCN=0.25 without ammonia, selectivity of SB is higher at lower temperatures. The selectivity to RNH2 decreased with reaction time for the experiment performed without NH3. The apparent activation energy of the hydrogenation of RCN on RNi-L catalyst was 30.5 kJ/mol, which is close to the value 46 kJ/mol measured in the liquid phase hydrogenation of acetonitrile on CoB amorphous alloy catalyt [7], RNi-C is more active than RNi-L catalyst (compare Table 1 No 4 and 6 and Table 2 No 7 and 8). 

For these reasons, the effect of support on Ni based catalysts is better shown when comparing the MEA selectivity at low acetonitrile conversions (Table 2). The improvement of primary amine selectivity upon Mg addition could arise from a modification of the acido-basic properties of the support surface. To check any differences in these properties, the acid sites were probed by TPD of NH3 and adsorption of MEA followed by calorimetry. 

The role of Lewis acids in the formation of oxazoles from diazocarbonyl compounds and nitriles has primarily been studied independently by two groups. Doyle et al. first reported the use of aluminium(III) chloride as a catalyst for the decomposition of diazoketones.<78TL2247> In a more detailed study, a range of Lewis acids was screened for catalytic activity, using diazoacetophenone la and acetonitrile as the test reaction.<80JOC3657> Of the catalysts employed, boron trifluoride etherate was found to be the catalyst of choice, due to the low yield of the 1-halogenated side-product 17 (X = Cl or F) compared to 2-methyI-5-phenyloxazole 18. Unfortunately, it was found that in the case of boron trifluoride etherate, the nitrile had to be used in a ten-fold excess, however the use of antimony(V) fluoride allowed the use of the nitrile in only a three fold excess (Table 1). 

Fig. 8 Reactions of various carbocations with Kuhn s anion [2 ] as compared with their reduction potentials (peak potentials measured vs. Ag/Ag in acetonitrile by cyclic voltammetry cf. Tables 1 and 8 and Okamoto et al., 1983). SALT, salt formation COV, covalent bond formation ET, single-electron transfer. 

A study of by Palmer-Toy et al.,12 summarized in Table 19.1, provides further empirical evidence of the utility of techniques coupling heating with efficient protein extraction for the proteomic analysis of FFPE tissue. A specimen from a patient with chronic stenosing external otitis was divided in half and preserved as fresh-frozen tissue or FFPE. Ten micromolar sections of the FFPE tissue were vortexed in heptane to deparaffinize the tissue and were then co-extracted with methanol. The methanol layer was evaporated, and the protein residue was resuspended in 2% SDS/lOOmM ammonium bicarbon-ate/20mM dithiothreitol (DTT), pH 8.5 and heated at 70°C for lh. After tryptic digestion, 123 total confident proteins were identified in the FFPE tissue, compared to 94 proteins identified from the fresh-frozen tissue. Hwang et al. also reported up to a fivefold increase in protein extraction efficiency for samples extracted in a Tris-HCl/2% SDS/1% Triton X-100/1% deoxycholate solution at 94°C for 30 min versus samples extracted in 100 mM ammonium bicarbonate/30% acetonitrile at the same temperature.14... 

In the direct ammoxidation of propane over Fe-zeolite catalysts the product mixture consisted of propene, acrylonitrile (AN), acetonitrile (AcN), and carbon oxides. Traces of methane, ethane, ethene and HCN were also detected with selectivity not exceeding 3%. The catalytic performances of the investigated catalysts are summarized in the Table 1. It must be noted that catalytic activity of MTW and silicalite matrix without iron (Fe concentration is lower than 50 ppm) was negligible. The propane conversion was below 1.5 % and no nitriles were detected. It is clearly seen from the Table 1 that the activity and selectivity of catalysts are influenced not only by the content of iron, but also by the zeolite framework structure. Typically, the Fe-MTW zeolites exhibit higher selectivity to propene (even at higher propane conversion than in the case of Fe-silicalite) and substantially lower selectivity to nitriles (both acrylonitrile and acetonitrile). The Fe-silicalite catalyst exhibits acrylonitrile selectivity 31.5 %, whereas the Fe-MTW catalysts with Fe concentration 1400 and 18900 ppm exhibit, at similar propane conversion, the AN selectivity 19.2 and 15.2 %, respectively. On the other hand, Fe-MTW zeolites exhibit higher AN/AcN ratio in comparison with Fe-silicalite catalyst (see Table 1). Fe-MTW-11500 catalyst reveals rather rare behavior. The concentration of Fe ions in the sample is comparable to Fe-sil-12900 catalyst, as well as... 

The epoxidation of hex-l-ene catalyzed by Ti-beta samples synthesized in the conventional, basic medium (Ti-beta(OH)) is compared in Table X with that catalyzed by a sample synthesized in a fluoride-containing medium (Ti-beta(F)) (13). The latter was more hydrophobic. Results for the reaction catalyzed by TS-1 are also included in Table X. Ti-beta(F) is superior to TS-1 for reaction in acetonitrile solvent. The most significant difference between Ti-beta(F) and Ti-beta(OH) is in their selectivities. Although the selectivity to the epoxide for reaction in acetonitrile is always very high, regardless of the zeolite for reaction in methanol, Ti-beta(F) is more selective than Ti-beta(OH) (76.6 vi. 54.9%, Table X). Both Ti-beta samples are, however, less selective than TS-1 for reaction in methanol. 

With regard to the chiral recognition by crown ethers D. J. Cram kindly informed us that the EDC value of 38 (footnote b, Table 67) proved to be in error, and that the reported RR-S configuration in Table 68, footnote d and page 403, is still uncertain. Recent work (Peacock et al., 1980) has shown that the chiral recognition of amino acids (page 397 and Table 69) is comparable to that of amino-acid esters. The peculiar optimum in EDC values as a function of acetonitrile concentration (page 401 and Table 72) could not be duplicated. 

Table 9 Rate constants for the reaction between TBPA + and Nu (as Bu4N+ salts in the appropriate cases) in HFP at 20°C, compared to acetonitrile.11...

On the other hand, Table 9 contains several data which cannot be interpreted by the relative donicities of donor solvent and competitive ligand the donor strength of the iodide ion is comparable to that of acetonitrile and the formation of tetraiodocobaltate in solvents of high donicity, such as DMA, DMSO and HMPA may not be anticipated. The formation of this species is however, complete with excess iodide ions and is due to the small values of the free enthalpies of the gas phase reactions ... 

Rh(4,4,-(CH3)2bpy)33+/Rh(4,4,-(CH3)2bpy)32+ couple (24). Similarly, E° estimates were obtained from quenching data for other RhL33+ couples (24). In Table 1 these estimates (E°(Q/Q )) are compared with E /2 values obtained via rapid sweep cyclic voltammetry in acetonitrile (Ei/2(CH3CN)). 

The general relationship between the type of solute and its retention can be seen by comparing the retention factors, k, of a set of standard compounds with their octanol-water partition coefficients, i.e. the logP value (listed in Table 4.1), as a measure of their relative solubility in water. The logarithm of the retention factor, log k, of these compounds measured in 50% aqueous acetonitrile on an octadecyl-bonded silica gel column shows a close linear relationship (Figure 4.1). 

For example, the CV oxidation and peak potentials of the 2,3-dihydrobenzo[b]-furan-5-ol series 98-101 in acetonitrile show the expected general trends (Table 11), although the oxidation of 98 is irreversible, that of 99 is quasireversible, and those of 100 and 101 are reversible.(These data illustrate the difficulty in comparing ease of oxidation even within a series of analogous compounds.) The authors compared the values found for these compounds with those of the arylmethylchalcogenides 94, 95b, 96b, and 97b (Table 10). They saw good correlation for the selenium and... 

The ability of molecules to accept a hydrogen bond is measured by the Taft-Kamlet solvatochromic parameter, P, (or P for the monomer of self-associat-ing solutes) (see Table 2.3). This, too, is a measure of their basicity (in the Lewis sense), also measured by the Gutmann donor number DN (discussed later). Thus, pyridine has P = 0.64, compared with 0.40 for acetonitrile, but... 

Among the various polar solvents tested, acetonitrile, dichloromethane, and THF afforded good yields of the expected product, although with moderate diastereo-selectivity (Table 16, entries 1-3). The most suitable solvent was found to be diethyl ether. 5-[Hydroxy(phenyl)methyl furan-2(5//)-one 28a was obtained with the best yield and diastereoselectivity (Table 16, entry 4). With further optimization of the reaction conditions, we found that a lower catalyst loading (0.5 mol%) did not allow the reaction to proceed (Table 16, compare entries 5 and 4), although a higher catalyst loading (5 mol%) afforded the product with close diastereoselectivity but decreased yield (Table 16, compare entries 6 and 4). 

In acetonitrile (dielectric constant — 35 (39)) the log K values for the reaction of the Na and K salts with the ligands are comparable. The log K values for the reaction of KC1 with these ligands in methanol (dielectric constant — 32 (39,40) are also comparable with those in acetonitrile. However, the log K values for the reaction of NaCl with both ligands in methanol is approximately one log K unit lower than the other values in the Table. Evans et al. (20) suggest that the altered selectivity may result from a larger decrease in the solvation of the Na compared with the K salt, with a subsequent rise in the stability of the Na complex relative to that of the corresponding K complex in going from methanol to acetonitrile. 

DNs range from zero (solvents like hexane, tetrachloromethane), through modest donors (acetonitrile 14.1, acetone 17), to good donors like water (18), to superb donors like DMSO (29.8) and, best of all, HMPA (38.8) (see table 3.7). The DN enables us to rationalize why a solvent such as nitromethane, (6r= 35.8) is considered to be fairly nonpolar, although it has a higher dielectric constant than diethyl ether (Sr = 4.2) and tetrahydrofuran (Sr = 7.6) which are often thought to be more polar solvents than their dielectric constants would indicate. The DN of nitromethane is only 2.7, compared with that of 19.2 for diethyl ether and 20 for tetrahydrofuran. These ether solvents are much better electron-pair donors than nitromethane. 

The heats of solution of lithium perchlorate in aqueous acetonitrile were measured at concentrations between 0.01 and 0.1m. The concentration dependence was small compared with the experimental scatter of about 0.1-0.2 kcal mole-1. AHs values are given in Table II. The heats of solution in anhydrous acetonitrile were corrected to infinite dilution using measured heats of dilution (6), and the corrected values were averaged. The heats of dilution were measured for lithium perchlorate in the mixed solvent containing 90% MeCN. 

In the literature (Pinal et al., 1991) you find data showing that the activity coefficient of anthracene is 400 times smaller in 40% acetonitrile / 60% water (v v) as compared to pure water. All other necessary data can be found in Table 5.8, Illustrative Example 5.5, and Appendix C. 

In Fig. 2, the simulated solvent response functions, S(t), are displayed for benzene-acetonitrile and benzene-methanol mixtures. To quantitatively compare this dynamics to the experimental work of Luther et al. on benzene-acetonitrile mixtures three exponential fits of the solvent response function were performed. The resulting weights, a, i = 1... 3, and times T,-, i = 1... 3 are reported in Table 1 and can be compared with the corresponding experimental values (Table 2). Good agreement between the two is achieved, except for the longer time at xp = 0.2 which may be due to statistical inaccuracy. 

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