Solvents chloroform

In Example 1 the solute, acetone, contains a ketone carbonyl group which is a hydrogen acceptor, i.e., solute class 5 according to Table 15-4. This solute is to be extracted from water with chloroform solvent which contains a hydrogen donor group, i.e., solvent class 4. The solute class 5 and solvent class 4 interaction in Table 15-4 is shown to give a negative deviation from Raonlt s law. 

The column was developed by washing it with 2,100 ml of benzene. The column was then washed sequentially with 300 ml of benzene-chloroform solvent (95 5 by volume) and 800 milliliters of benzene-chloroform solvent (75 25) to remove Indeterminate impurities. The leurosine was eluted from the alumina by passing over the column 900 ml of benzene-chloroform solvent (50 50). 

Further elution of the above chromatographic column with a 50 50 benzene-chloroform solvent mixture or with a 25 75 benzene-chloroform solvent mixture serves to elute vinca-leukoblastine. Vincaleukoblastine also occurs in the latter fractions containing leurosine. Vincaleukoblastine is obtained from vincaleukoblastine-containing fractions by evaporation... 

A strong acceptor TCNE undergoes [2+2] rather than [4+2] cycloaddition reactions even with dienes. 1,1-Diphenylbutadiene [20] and 2,5-dimethyl-2,4-hexadiene (Scheme 5) [21] afford mainly and exclusively vinyl cyclobutane derivatives, respectively. In the reactions of 2,5-dimethyl-2,4-hexadiene (1) the observed rate constant, is greater for chloroform solvent than for a more polar solvent, acetonitrile (2) the trapping of a zwitterion intermediate by either methanol or p-toluenethiol was unsuccessful (3) radical initiators such as benzyl peroxide, or radical inhibitors like hydroquinone, have no effect on the rate (4) the entropies of activation are of... 

Among methylene chloride, chloroform, carbon tetrachloride, and hexane, fast reaction rate was observed in methylene chloride or chloroform solvents, but slow... 

Figure 12.3 AFM images of thin PS-fo-P4VP (162 400 87 400) films (chloroform solvent)...

Fabric Cleaning. The Kevlar-29 woven fabric was obtained through the courtesy of Naval Weapons Center. A special pair of serrated shears was purchased from Technology Associates for cutting the fabric. The fabric (2.5 cm x 18 cm) was placed in a Soxhlet thimble and extracted by 100 ml of chloroform for 24 hours to remove its surface lubricants (about 3% by weight). The fabric was then removed from the thimble and agitated in a 20 ml of hot distilled DMAc for 15 minutes, before it was placed back into the thimble and extracted for another 8 hours using fresh chloroform solvent. The solvent-cleaned fabric was dried in a vacuo at room temperature. 

When 4-/-butylcyclohex-1 -enyl(phenyl)iodonium tetrafluoroborate (3) is heated at 60 °C in chloroform, 1-fluorocyclohexene 4, 1-chlorocyclohexene 5 and l-(o-iodophenyl)cyclohexene 6 are formed with accompanying iodobenzene leaving group (eq 2).3 These three substitution products are best accounted for by formation of an ion pair involving cyclohexenyl cation 7. The cyclohexenyl cation 7 formed picks up fluoride from tetrafluoroborate and chloride from chloroform solvent, and recombines with the iodobenzene generated (eq 3). This kind of reactions with a counteranion and solvent are characteristic of unstable carbocations and are known in the case of phenyl cation generated from the diazonium salt in the Schiemann-type reaction.4... 

H NMR (400 MHz), NMR spectra were recorded on a Varian Mercury-Vx (3000Mx) ve Brucker AC-400L spectrometer using deuterated chloroform solvents and TMS as internal standard. IR spectra were recorded on a Schimadzu Fonrier Transform FTlR-8300 instalment. Mass spectra were recorded on a VG Zap spec instrument (1,000 resolution) (the Chemistry of the Turkish Scientific and Research Institue-Gebze). 

Table 2 contains the characteristics of the amic ester-aryl ether copolymers including coblock type, composition, and intrinsic viscosity. Three series of copolymers were prepared in which the aryl ether phenylquinoxaline [44], aryl ether benzoxazole [47], or aryl ether ether ketone oligomers [57-59] were co-re-acted with various compositions of ODA and PMDA diethyl ester diacyl chloride samples (2a-k). The aryl ether compositions varied from approximately 20 to 50 wt% (denoted 2a-d) so as to vary the structure of the microphase-separated morphology of the copolymer. The composition of aryl ether coblock in the copolymers, as determined by NMR, was similar to that calculated from the charge of the aryl ether coblock (Table 2). The viscosity measurements, also shown in Table 2, were high and comparable to that of a high molecular weight poly(amic ethyl ester) homopolymer. In some cases, a chloroform solvent rinse was required to remove aryl ether homopolymer contamination. It should also be pointed out that both the powder and solution forms of the poly(amic ethyl ester) copolymers are stable and do not undergo transamidization reactions or viscosity loss with time, unlike their poly(amic acid) analogs.

Waste water Extraction with chloroform, solvent exchange to methanol, volume reduction. HPLC/EC (EPA Method 605) 0.13 g/L 64 (96% RSD) EPA 1982a > Z > r <... 

Initially, a series of monoamic acids was prepared in chloroform from substituted phthalic anhydrides and 4-fluoroaniline (Figure 17.4). These syntheses resulted in nearly quantitative yields of crystalline amic acids, which precipitated from the chloroform solvent when cooled. The spectra were measured on these compounds Table 17.1 summarizes the data and indicates in each case which isomer was preferentially formed in chloroform from similar carbon peak heights. Most of the results followed the expected trend as die electron-withdrawing capability of any substituent increased, the carbon wilh which dial substituent could interact by resonance became more electrophilic and was subsequently attacked preferentially by 4-FA. For example, in 4-nitrophthalic... 

Finally, inspection of Table 3.2 shows also that there are cases in which Yu can be even smaller than 1. An example is a solution of diethylether in chloroform. Here, the solute is an electron donor (H-acceptor), while the chloroform solvent is an electron acceptor (H-donor). In this case, the solute and solvent both acquire additional inter-molecular interactions that were unavailable to them in their pure liquid forms. The monopolar diethylether (only vdW interactions in its pure liquid) can add polar interactions to its vdW attractions with the molecules of the monopolar chloroform solvent exhibiting a complementary electron acceptor property. 

In chloroform solvent, the platinum dithiolene complexes Pt(S2C2R2)2 are photooxidized between 300 and 350 nm, providing the complexes used are those for which the R groups result in redox potentials in the 0.1 to 0.5 V (vs SCE) range. The results are consistent with the reaction shown in equation (534).1849 Further work on this system identifies the fact that several excited states are probably photoreactive in this process,1850 and no definitive answer on the excited state reactivities is yet available. Very recently, however, highly structured solid-state emissions have been observed for Pt S2C2(CN)2 P(OR)3 2, and this data may help resolve some of these questions.1851... 

The authors have used ratios of ace-tone/chloroform varying from 1 1, 1 2, 1 2.4, to even 1 5. A greater proportion of chloroform reduces the amount of acetone in the aqueous phase and may eliminate the need for removal of acetone by rotary evaporation. This evaporative step, however, takes little time with no apparent anthocyanin degradation. Therefore, the authors favor using 1 1 or 1 2 ratios to avoid excessive use of the chloroform solvent. 

A measured quantity of solid sample mixed with anhydrous Na2S04 the mixture sonicated or Soxhlett extracted with methylene chloride or chloroform solvent extract concentrated cleanup (if required) by acid-base partitioning analyzed as above by GC/MS using an appropriate column. 

Another consideration when selecting an extraction solvent is its density [41]. Solvents that are more dense than water will form the lower layer of the pair when mixed together, while solvents that are less dense than water will form the upper layer or float on water. For example, ethyl ether has a density of 0.7133 g/mL at 20°C and would constitute the upper phase when combined with water, which has a density of 0.9982 g/mL at that temperature. On the other hand, the density of chloroform is 1.4892 at 20°C. Therefore, water would form the top layer in a water chloroform solvent pair. 

Phenolic extraction of cell lysates is one of the oldest techniques in DNA preparation. Examples of these have been presented in Chapters 6 and 7. Single cells in suspension are lysed with a detergent, and a proteinase enzyme is used to break down the protein molecules. Non-nucleic acid components are then extracted into an organic (phenol-chloroform) solvent, leaving nucleic acids in the aqueous layer. Two volumes of isopropanol are added to the isolated aqueous phase to precipitate the high-molecular-weight nucleic acids as a white mass. These are then treated with DNase-free ribonuclease (RNase) to remove the RNA. This is followed by a second treatment with proteinase, phenol extraction, and isopropanol precipitation. After precipitation, the DNA is separated from the isopropanol by... 

A mixture of 20.0 g of 3-hydrazino-4-methyl-6-piperidinopyridazine in 100 ml of aqueous 99% formic acid was heated at the boiling temperature under reflux for 3 h and then evaporated to dryness. The residue, containing 8-methyl-6-piperidino-s-triazolo[4,3-b]pyridazine formate was taken up in excess aqueous sodium carbonate and extracted with chloroform. After evaporation of the chloroform solvent the 8-methyl-6-piperidino-s-triazolo[4,3-b]pyridazine was crystallized from ethyl acetate. Yield 4.4 g, melting point 118-120°C. 

The parent compound, 1,2,3-thiadiazole, is soluble in alcohol, ether and water. Most 1,2,3-thiadiazoles are freely soluble in methylene chloride and chloroform. Solvents such as ether and alcohol have been used to recrystallize 1,2,3-thiadiazoles. No systematic study of the solubility characteristics of 1,2,3-thiadiazoles has been undertaken. 

In Fig. 13 are shown typical spectra for 15% solutions of two methyl methacrylate polymers in chloroform. The polymers were prepared with (a) benzoyl peroxide in toluene at 100° and (b) n-butyllithium at — 62°. The large peak at the left is that of the chloroform solvent. The ester methyl group appears at 6.40r in both spectra, and is not affected by the chain conformation. There are three cc-methyl peaks, at 8.78t, 8.95 t, and 9.09r, whose relative heights vary greatly with the method of polymer preparation. Polymers prepared with n-butyllithium show a very prominent peak at 8.78r, the others being much smaller. Polymers prepared with benzoyl peroxide initiator show the same three peaks, but now the peak at 9.09r is the most prominent. 

Alternatively, direct electrophilic acylation of a BIPS also occurred in the 3-position. Vilsmeier formylation of 6-nitroBIPS gave 22% of the 3-formyl derivative (113, R=H) acetic anhydride with boron trifluoride etherate in chloroform solvent gave 56% of the 3-acetyl compound (113, R=Me) and benzoyl chloride with aluminium bromide in carbon disulfide solvent gave 26% of 3-benzoyl-6-nitroBIPS (113, R=Ph). None of the 3-acyl BIPS showed any coloration upon UV irradiation in any solvent.106... 

This technique, based on the precipitation of a hydrophobic polymer, is useful for the encapsulation of either hydrophilic or hydrophobic drugs because a variety of solvents, including polar (e.g., acetone or methanol) and non-polar (methylene chloride or chloroform) solvents can be chosen for dissolving the drug. This procedure is just like nanoprecipitation, however, the miscibility of both phases is prevented by the saturation of the external aqueous phase with PVA. Precipitation occurs when a sufficient amount of water is added to allow complete diffusion of the acetone into the aqueous phase. 

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