Chloroform, addition

Often, the osone hydrate crystallizes spontaneously within a few minutes after the addition of water and may be extracted from the contaminating salts with chloroform. Additional crystals may be obtained by adding petroleum ether to the ethereal mother liquor. 2,3,4,6-Tetra-O-acetyl-D-glucosone hydrate is soluble in water, ethanol, and chloroform difficultly soluble in ether or benzene and insoluble in petroleum ether.16... 

The occurrence of nicotine in Withania aomnifera Dun. has been recorded (74). A number of other alkaloids were also isolated from the same plant as follows somniferine, m.p. 185-187° (dec.), somniferinine, m.p. 120° (after decomposing 87-100°), somnine, m.p. 300°, withanine, m.p. 87-88° (dec.) (chloroaurate, m.p. 170-175°), withananine, m.p. 75-80° (picrate, m.p. 176-178° chloroaurate, m.p. 115-119°), and pseudowithanine, m.p. 155-156° (dec.). Withanine is a chloroform addition compoimd, C44H80O12N3.CHCI2. When distilled with soda-lime it yielded pyrrole and myosmine ( ) (74). 

In ordinary homolytic reactions (as distinguished from the reaction described here), chloroform adds to the double bond in the sense H—CC13.4 Bromodichloromethane adds in the sense Br—CHCU,3 similar to the orientation of chloroform additions in the present method (Cl—CHCU). The present method... 

Fig. 2 Cumulative gas production for chloroform addition to granules sludge culture (Batch culture, 20 mL glucose culture medium, 3 days, inoculums 3 mL). Data are averages with error bars showing standard deviations ( =3)...

Chloroform/methanol precipitation Wessel and Flugge (1984) dilute watery protein solutions (volume of 10 to 150 pi) in Eppendorf tubes with methanol and precipitate the proteins with chloroform. Addition of water separates the water/methanol/chloroform solution into two phases. The precipitated proteins collect in the interphase. Test volumes of 0.2 to 2 ml can also be processed with Corex glass tubes. 

The adsorption of molecular probes, followed by infrared or NMR spectroscopy and thermal desorption studies, is the most commonly adopted way to study basic sites. Carbon dioxide is frequently used in infrared studies, particularly of cationic zeolites with added alkali metals.Chloroform is also suitable, since the interaction with the chlorine atom and subsequently the C-Cl stretching frequency is a measure of the basic strength. NMR studies of basic zeolites have concentrated on the use of C containing probes such as methyl iodide and chloroform. Addition of methyl iodide results in its decomposition and the formation of methoxy groups at framework oxygens. The shift of the methyl carbon is expected to be related to the basicity of the framework, that is the tendency of the framework oxygens to donate electrons - C MAS NMR of methoxy groups prepared in this way shows a clear distinction between basic zeolites, such as Cs-X, and acidic zeolites, such as H-ZSM-5. 

Procedure A drop of the neutral or acid test solution is treated successively in a micro test tube with four drops of the reagent solution, one drop of a 10% sodium hydroxide solution and one drop of 10% sodium carbonate solution and extracted with 3-4 drops of chloroform. Addition of a few drops of water hastens the separation of the two layers. A red color in the CHCI3 layer indicates the presence of calcium. When testing for small amounts of calcium a blank test is advisable. 

Fig. 2. Timed extraction study for Cd(II) Schiff-base. Extraction started with either 0.0500 mM Cd(PCA-2)2 in chloroform and 5.00 mM CHES (pH = 8.5) and 0.100 M NaCl in water (chloroform) or 0.100 M NaCl, 5.00 mM buffer (pH = 8.5), 0.0500 mM and 0.100 mM PC A and 2AP in water followed by chloroform addition (water).

When 1 was treated with pyridine (1.5 equiv) in dry diethyl ether or chloroform, addition of water (1.2 equiv) afforded a new complex (9) that was converted to 7 over 1-2 hours (Scheme II). H NMR indicated a formulation involving a 1 1 1 ratio of bis(trimethylsilyl)cyclopentadienyl, acetylacetonate, and pyridine ligands. The infrared spectrum did not show O-H absorotions, which ruled out an aquo or hydroxo complex. The oxo-bridged dimer 9 is proposed based on these data and on the facile hydrolysis of 9 to 7. Other structures for 9 are possible. Unfortunately, the limited thermal and hydrolytic stability of 9 precluded its further characterization. 

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