Acetonitrile behavior

Vanadium(III) Chloride. Vanadium(III) chloride (vanadium trichloride, VCl ) is a pink-violet sohd, is readily hydrolyzed, and is insoluble in nonpolar solvents but dissolves in donor solvents, eg, acetonitrile, to form coordination compounds. Chemical behavior of the tribromide (VBr ) is similar to that of VCl. ... 

Mark-Houwink constants for PEG, PEO, and PSC are summarized in Table 20.4. These were measured in either an aqueous mobile phase of 0.10 N NaNOi or a mobile phase of 20% acetonitrile in aqueous 0.10 N NaNOi (which also exhibits universal calibration behavior). The values for a fall within... 

Photolysis of derivatives of compounds 4 and 5 has been further studied as a route to azacarbazoles. The example 264 shows normal behavior as well as elimination of an alkoxy group, and the report includes examples of derivatives of compound 5 as well as references to earlier work (93JCS(P1)1261). Production of an intermediate for an anti-tumour ellipticine analogue is shown by example 265 (84MI1), and incorporation of acetonitrile solvent by example 266 (91TL323). 

Most recent syntheses of fluorinated benzothiazoles make use of nucleophilic substitution. Potassium fluoride in acetonitrile converted 40 into the 2-fluoro derivative (R = 6-nitro) in 99% yield. When the solvent was dimethylformamide the 2-dimethylamino derivative was formed instead [80JCS(P1)2358], and similar behavior was reported earlier (77BSF171). 

The coordination of redox-active ligands such as 1,2-bis-dithiolates, to the M03Q7 cluster unit, results in oxidation-active complexes in sharp contrast with the electrochemical behavior found for the [Mo3S7Br6] di-anion for which no oxidation process is observed by cyclic voltammetry in acetonitrile within the allowed solvent window [38]. The oxidation potentials are easily accessible and this property can be used to obtain a new family of single-component molecular conductors as will be presented in the next section. Upon reduction, [M03S7 (dithiolate)3] type-11 complexes transform into [Mo3S4(dithiolate)3] type-I dianions, as represented in Eq. (7). 

Nakatani K, Matsudaiva S, Tsubomura H (1978) Photoanodic behavior of n-type cadmium sulfide in acetonitrile solutions containing iodide ion. J Electrochem Soc 125 406 09... 

Laser D, Bard AJ (1976) Semiconductor Electrodes. IV. Electrochemical behavior of n- and p-type silicon electrodes in acetonitrile solutions. J Phys Chem 80 459 66... 

GL 1[ [R 1[ [P la[ The residence time distribution between the individual flows in the various micro channels on one reaction plate of a falling film micro reactor was estimated by analysing the starting wetting behavior of an acetonitrile falling film [3]. For a flow of 20 ml h it was found that 90% of all streams were within a 0.5 s interval for an average residence time of 17.5 s. 

The short Au Ag contacts may be due to some degree of metal-metal bonding which means that these were the first reported Au—Ag bonds. The complexes with acetone and acetonitrile shown are also the first reported examples in gold chemistry in which the pentafiuorophenyl ligands act as a bridge between Au and Ag centers. This type of behavior is generally more common in Pt chemistry. 

The l-(7V-methyl)benzimidazolyl-3-benzimidazolyl-2-oxapropane ligand (107) shows coordination through the N20 donor set of the ligand, a water molecule and an acetonitrile to give a five-coordinate distorted trigonal-bipyramidal metal center.123 This contrasts with the behavior of the related thiapropane ligand that forms bidentate complexes with zinc. 

The substitution-inert character of the metal(III) ion in the second transition series has already been discussed in 2.3. However, interesting behavior has been reported by Kasahara et al. [23], who found that a p-diketone coordinated to the central Ru(III) could easily be replaced by an acetonitrile with the aid of a strong acid. When the reaction was conducted in acetonitrile, its stoichiometry was confirmed by means of spectrophotometrie titration as follows ... 

The apparent rate constant kapp depends on the concentration of hydroxide ion as is shown in Fig. 1. The absorption maxima of TcCl2(acac) 2 in chloroform appear at 281,314(sh), 340(sh), 382 and 420 nm. On the other hand, the spectrum of the aqueous phase exhibits absorption maxima at 292,350 and 540 nm. The absorbances at 350 and 540 nm increase with time, but decrease after reaching maxima. This suggests that the chemical species which is formed by the back-extraction of TcCl2(acac)2 decomposes with time. In order to clarify the behavior of chloride ion liberated from the complex, an electrochemical method was introduced for the homogeneous system. In acetonitrile, no detectable change in the spectrum of TcCl2(acac)2 was observed. On the addition of an aqueous solution of hydroxide, however, the brown solution immediately turned red-violet, and exhibited absorption maxima at 292,350 and 540 nm. The red-violet... 

We have also examined the behavior of copolymers of o-tolyl vinyl ketone and methyl vinyl ketone (CoMT). In this case the light is absorbed exclusively at the aromatic carbonyl chromophore and the reaction proceeds from this site, while the methyl vinyl ketone moieties provide a relatively constant environment but prevent energy migration along the chain. The values of Tg and Tip in benzene have been included in Table II. These copolymers axe also soluble in some polar solvents for example, we have used a mixture of acetonitrile acetone methanol (30 30 Uo, referred to as AAM). This mixture is also a good solvent for the electron acceptor paraquat (PQ++) which has been shown to be good biradical trap in a number of other systems (9.). 

The catalytic behavior of Fe-MTW zeolites in the direct ammoxidation of propane was investigated. The obtained catalytic results are compared with behavior of Fe-silicalite catalysts whose activity in propane ammoxidation was recently published. It was found that Fe-MTW catalysts exhibit the similar activity as Fe-silicalites but the selectivity to acrylonitrile was substantially lower. On the other hand, Fe-MTW catalysts produce higher amount of propene and have better acrylonitrile-to-acetonitrile ratio. 

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... 

Fluoride ion is effective in promoting the reduction of aldehydes by organosil-icon hydrides (Eq. 161). The source of fluoride ion is important to the efficiency of reduction. Triethylsilane reduces benzaldehyde to triethylbenzyloxysilane in 36% yield within 10-12 hours in anhydrous acetonitrile solvent at room temperature when tetraethylammonium fluoride (TEAF) is used as the fluoride ion source and in 96% yield when cesium fluoride is used.83 The carbonyl functions of both p-anisaldehyde and cinnamaldehyde are reduced under similar conditions. Potassium bromide or chloride, or tetramethylammonium bromide or chloride are not effective at promoting similar behavior under these reaction conditions.83 Moderate yields of alcohols are obtained by the KF-catalyzed PMHS, (EtO SiH, or Me(EtO)2SiH reduction of aldehydes.80,83,79... 

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