Acetone solvent uses

Cleaning before use Remove the flow cell and gently flush with tap water. The acrylic flow cell can be easily scratched. Wipe with cloth only." Do not allow center tube, where sensors detect soap film to be scratched or get ditty. Never clean with acetone solvent. Use only soap and warm water. When cleaning prior to storage, allow flow cell to air dry. If... 

Example 6 Solvent Rate for Absorption Let us consider the absorption of acetone from air at atmospheric pressure into a stream of pure water fed to the top of a packed absorber at 25 C. The inlet gas at 35 C contains 2 percent by volume of acetone and is 70 percent saturated with water vapor (4 percent H2O by volume). The mole-fraction acetone in the exit gas is to be reduced to 1/400 of the inlet value, or 50 ppmv. For 100 kmol of feed-gas mixture, how many Idlomoles of fresh water should be fed to provide a positive-driving force throughout the pacldug How many transfer units will be needed according to the classical adiabatic method What is the estimated height of pacldug required if Hqq = 0.70 m ... 

Example 1 Partition Ratios Let us estimate the partition ratio in weight fractions K for extracting low concentrations of acetone from water into chloroform. The solute is acetone, the feed solvent is water, and the extraction solvent is chloroform in this case. 

Water is a possible axial ligand for the transient Ni(PP) in these systems and has been shown to form weak complexes with other nickel porphyrin species (18). While we cannot unequivocally rule out weak, transient ligation, the observation of similar transient behavior in Ni(OEP) and Ni(PPDME) in noncoordinating, nonaqueous, solvents (toluene, methylene chloride (9, unpublished results)) leads us to conclude that the transient behavior of the Ni(PP) in acetone/water is not predicated upon ligand binding. 

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. 

DOPDA h as been used as an addidve to rubber.composidons at the time of manufacture for the purpose of providing ozone resistance to elastometers. Mixtures of DOPDA with solvents such as acetone (usually in 50/50 ratio) are flammable and toxic, causing skin irritation. The material covered by US Military Specification MIL-D-50000A(MR), July 1966 is intended for use as an externally applied (brush or dip) solution to rubber items, particularly tires. This chemical functions as an antiozonant, preventing cracking of stressed, vulcanized rubber items in outdoor storage Requirements and tests covered by the above Spec are as follows ... 

Let us now turn again to the problem of the thermodynamic quality of the solvent. In the above examples, the solvent quality was different. Thus, for PDEGA in the hexane — MEK mixture, only MEK. is good on the contrary, for polybutadienes hexane is a good solvent. In the chloroform-acetone mixture both solvents are good for PDEGA. Thus, the use of solvents with a different thermodynamic quality in binary mixtures has no qualitative effect on separation it is only necessary that the sample should be readily soluble in binary mixtures whose composition is close toC. ... 

Specification Requirements for Acetone Used in Ordnance. Acetone intended for use as a solvent in prepn of propellants and pentolite shall comply with the requirements of US Spec JAN—A—489 and shall be tested according to the procedures outlined below ... 

This problem is similar to Problem 14.2 except that the solvent is acetone, not water (disassociation does not occur in organic solvents i = 1). Let us use the same technique as following Problem 14.2. 

Addition of nucleophiles to electrophilic glycine templates has served as an excellent means of synthesis of a-amino acid derivatives [2c, 4—6]. In particular, imines derived from a-ethyl glyoxylate are excellent electrophiles for stereoselective construction of optically active molecules [32], This research and retrosyn-thetic analysis led us to believe that amine-catalyzed asymmetric Mannich-type additions of unmodified ketones to glyoxylate derived imines would be an attractive route for synthesis of y-keto-ce-amino acid derivatives [33], Initially, L-proline-catalyzed direct asymmetric Mannich reaction with acetone and N-PMP-protected a-ethyl glyoxylate was examined in different solvents. The Mannich-type reaction was effective in all solvents tested and the corresponding amino acid derivative was isolated in excellent yield and enantioselectivity (ee >95 %). Direct asymmetric Mannich-type additions with other ketones afford Mannich adducts in good yield and excellent regio-, diastereo- and enantioselectivity (Eq. 8). 

Let us now consider Scheppele s discussion of the solvolysis of 2-d-exo- and -endo-bicyclo[2.2.1] hept-2-yl p-nitrobenzoates and p-toluenesulfonates. A maximum a isotope effect of 1 22 is suggested for kH/kD for the limiting solvolysis of simple secondary sulphonates (solvolyses where the rate is not affected by the nucleophilicity of the medium). The endo-esters yield a similar value which might be taken to imply the absence of steric hindrance in their reaction. However, whereas the maximum isotope effect for the simple sulphonates is believed to arise partly from an activated complex in the conversion of the internal ion pair into a solvent-separated ion pair, B - C, the effect in the endo-norbomyl compounds is suggested to arise during the transition state involved in the formation of the intimate ion pair, A - B. The latter is deduced from the fact that polarimetric and titrimetric rate constants are the same in acetic acid, aqueous acetone and ethanol (Winstein and Trifan, 1949 and 1952). If this is the case, the endo-effect of 1-20 should be... 

The effeot of US on find is especially significant at low absolute supersaturations thus, oontradiotory results have been obtained for highly supersaturated solutions [140]. Figure 5.13 illustrates the effects for the anti-solvent crystallization of roxithromycin in an acetone-water mixture [141]. As can be seen in Fig. 5.13A, the induction time decreased as supersaturation increased, whether or not US was applied. However, US significantly reduces the induction time, particularly at low supersaturations. Therefore, the effect of US on nuoleation is stronger than that of high supersaturation levels [142]. 

Returning to our example solvent-separation problem, let us consider using liquid/liquid extraction to remove pentane from methanol and/or acetone. A suitable solvent is one that is immiscible with the bulk species, pentane. If at all possible, we would like the solvent to be present in the mixture so we do not have to introduce any other species into our separations problem. For our example problem, water is present. Noting the infinite-dilution A -values for water and pentane, we see that water will be highly immiscible with pentane. 

Use Method 106.1 of MIL-STD-650 with.acetone as solvent Weigh ca 50g of die expl to widiin lOmg, place in a 400-ml beaker and add lOOml of acetone. Heat on a steam bath until all lumps are broken and all soluble material is dissolved. Pour die mixture thm a small US Standard Sieve No 60 and wash tjje insol matter from the beaker onto the. sieve with a stream of acetone. Wash the tesidue on die sieve with addnl acetone to remove die undissolved soluble material. 

The nature of proton sponges does not allow them to be used directly as kinetically active bases, e.g. in E2 elimination reactions, involving the ionization of C—H bonds213. However, due to the low nucleophilicity, the proton sponges are useful reagents when it is necessary to bind an acid liberated in the course of the reaction without any effect on other base-sensitive groups. As a rule, in such cases, a proton transfer from substrate to the proton sponge requires an additional carrier, which most frequently is the solvent molecule (such as alcohol, THF, DMSO, acetone)57,214,215. Let us consider some typical examples. 

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