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13




, 1,2- . The mechanism of the first reaction is reasonably well established as nucleophilic 1,2-rearrangement of alkyl from boron to oxygen.

, . This may be taken as the result of overheating.

, , . .Considering the hydrolysis as first order reaction it is possible to draw some conclusions.

' , - . D'Herelle


conceived of this phenomenon as an infection of the bacterial host cell by a virulent virus particle.

, . Radicals were once thought of, in the organic nomenclature sense, as fragment of molecules.

, . This rearrangement has been well established as an intramolecular process.

, , . Resistance of cyclopentane and cyclohexane to hydrogenation characterizes them as less reactive than cyclobutane.

, 4 1? 1. Should the value of p for ammonium ion be chosen as four or one? It is generally chosen as one.

, . The rearrangement of an alkyl aryl ether to an alkylphenol can be thought of as an aromatic alkylation, and may take place as a true intramolecular rearrangement.

, , , . In general one may designate as acidimetry or alkalimetry any titration whose end-point is recognized by a change in hydrogen-ion concentration.

, , , , . It is essential to make sure that no other reducible substance could be present, for it would erroneously be counted as one of the five being determined.

, , , - , . Likewise, but in a broader sense, hydrolytic precipitations or complex formations may be classified as acid-base reactions, for in them the hydrogen-ion concentration changes suddenly with the first excess of reagent.

, 22 , , , , . The possibility of representing the rate of iodination of


acetone by equation 22 was viewed by Swain as evidence for the termolecular mechanism being generally valid for reactions subject to general acid base catalysis.

219. - . - .

:

, , . Only those substances which can be considered as being mixtures have a depressed melting point.

, . By far the most important example is the one-step synthesis of butadiene from alcohol, which is reputed to account for the bulk of USSR synthetic rubber.

, , () , . Grunwald and Winstein have established a quantitative scale which is alleged to be a measure of the ionizing power of solvent.

, Fμ. , , , . We considered it to be a drawback that in matrix representation the Eμ have properties additional to those which they are defined to have as constituents of a complete orthogonal set.

, , , , , . The first compounds, that were recognized to possess the thiasole ring are best considered as derivatives of tetrahydrothiazole.

, , , , . It was soon found that many sera contain what have been termed cold agglutinins which apparently act upon all human bloods.

, , , , , , . A rough idea of what is thought to be taking place is given by the formula below, the dotted curved


arrows indicating the movement of single electrons and not of electron pairs.

, , , . It gives a semicarbazone which was interpreted to mean the presence of a free aldehyde group.

, , -, Et SSK. The solution turns yellow which is believed to be due to EtSSK.

. - , . . (. 216):

, , , , . found that, in the presence of small amounts of water ethylene oxide forms a series of ethers which he thought to be polyethers.

, , , . They obtained a crystalline substance which they believed to be aspartimide.

, , , , --2- 3-, . Steinkopf and Kohler have reported from the chlorination of thiophene a compound that they believed to be pentachloro-2-or 3-thiophene, but recent investigators have not been able to duplicate these results.

220, - . - , .

:

, , , , . Several such endeavors, initially believed successful, later proved to have yielded dimers of the expected radicals.

, , , , . The non-phototropic phenylhydrazones of these compounds, believed to be anti-alkyl, do yield pyrazolines.

, , , , , . Samples observed to remain liquid on cooling are readily recognized as being of lower grade.

, , , , . This method, previously mentioned as affording good results, is now widely used.


, , , , , , . The organic compounds cited above as being insoluble in water do not contain hydroxyl groups and are in this and other respects unlike water.

3-, , , 5-α-. Removal of the protective group gave a 3-monoketone characterized as having the 5-α-configuration by the rotatory dispersion curve.

, , , . Some factors known to affect markedly the efficiency of planting may be mentioned by way of example.

, , , 6- , 10 400 /. The gas rates reported in literature as having been employed for columns of 6 mm range from 10 to 400 ml/min.

, , 1902 . . Supposing the ring systems of morphine and apomorphine to be the same, Pschorr suggested in 1902 a peridine-formula for morphine.

, , . Finding Pschorr's hypothesis to be inconsistent with their experimental observations, Knorr and Horlein proposed an alternate formula.

, , . Considering the hydrolysis as being first order reaction it is possible to draw some conclusions.

, , . Knowing my friends to be busy I decided to call on them myself.

, , d- 1-, . Hence, it is necessary to specify the solvent when speaking of a certain optical isomer as being the d-isomer or 1-isomer.

, , , . Taking these forms for simplicity as being individuals rather than the canonical extremes of a mesomeric hydrid we get the following.

, , , . Assuming Butenandt's formula to be


correct, it seemed altogether probable that androsteron arises in the organism as a degradation product.

, - , 0- . Taking the configurations of the p-nitrobenzophenone oximes as known, one can measure the moments of their 0-methyl-ethers.

, 100, -, -, - 32: 49: 65. With the benzene hydrogenation rate assumed to be 100, o-xylene, m-xylene, and p-xylene hydrogenate in the ratio of 32: 49: 65.

, , -, , , . Norrish has carried out experiments enabling this theory to be applied and seeming to represent cases in which mainly the two steps, start and growth, interfere with each other.

, , -, . In view of our finding laevoglucosan as a product of the acid-reversion of glucose it seems likely that this material is laevomannosan.

, , . This can best be explained by assuming the magnesium complex to consist of the following equilibrium mixture.

, , , . 5657. This reaction could be explained by assuming hydrogen to act as a pseudohalogen, in which case the reactions discussed on p.p. 5657 are pertinent.

, , . The reaction is most easily interpreted by imagining it to involve generation of hydroxyl radical.

, . The chemist is usually inclined to regard the appearance of this product as signifying that the reaction is over.

221. -. , - (. 87).

:


 



. The idea is now seemingly obvious.

, . This unit conceivably could bind together two peptide chains.

, , , , . Reputedly highly satisfactory is the method of isolation employed by Girard but not yet fully described in the scientific literature.

222. -. - as + (). :

, , . However, insufficient data are available at present to allow the unequivocal identification of bands at either of these positions as being due to this cause.

, , . The recent recognition of phosphonitrilic compounds as aromatic systems has stimulated research.

, - , , 1950 -1 --. The most which can be derived from the infra-red spectrum is the identification of the skeleton X-C-X as being correlated with the appearance of a medium intensity absorption band near 1950 cm -1.

. , - (to formulate) - (formulation):

o-Aminothiophenol reacted additively with 1 mol. of various diarycarbodi-imides to afford high yields of products which are formulated, on the basis of their mode of formation composition, molecular weight, and chemical properties, as S-o-aminophenyl-NN''-diarylisothioureas (I). It is well known that carbodi-imides condense with ammonia or amines to yield substituted guanidines; they also react with thiols, affording for example SNN '-triphenylisothiourea with thiophenol. The formulation of the present series of compounds as isothioureas


(I), and not as guanidines (la), implying a more rapid attack carbodi-imides at the thiol than at the amino-group in o-aminothiophenol, is based on the chemical behaviour of the products.

223. : for + () + . for + () + ( to), , , , . , , . . . :

, , . Two hours were sufficient for the reaction to occur.

, . The problem is far too involved for one to be able to solve it.

, , . For this mesomerism to be possible the ion must have a planar configuration.

, , ; -. For the oxidation to be specific, the alkoxide alcohol must itself be incapable of oxidation; thus aluminum t-butoxide was used as the catalyst.

, , , 90% C-V, 10 . Stated differently, the time taken for about 90% of the rising part of a C-V curve to be covered represents about 10 drop lives for a reversible one-electron reaction.

7, 4, 7,4. It is impossible for ice to be at equilibrium with crystalline silver nitrate at any temperature above 7.4, or for an aqueous solution of silver nitrate to be at equilibrium with ice or the crystalline salt at any temperature below 7.4.

, . This mechanism is provided with special devices for the whole system to function automatically.

. for in order for.


, , . In order for this cleavage to occur without acid catalysis, the carbonium ion to be formed should be more stable.

, . In order for lysis to occur the host cells must be growing in an appropriate physical and chemical environment.

224. to cause, to make, to force, to lead, to get + + () + . , .

:

, , . Electrolytic reduction is also used, but many other reagents cause the nitrogen to be split off as ammonia.

, , , , , . Sulfation in the presence of dehydrating agents such as acetic anhydride is also useful in causing the reaction to go to completion.

, 7 , . It may be assumed that steric influence causes the heat of polymerisation to be 7 kcal less than expected.

, . Several requirements have to be satisfied to make such a still operate efficiently and without error.

, , . Silicon tetraacetate was much more stable and could be made to react with such compounds as alcohol, ether, and ammonia.

. They made the fluid flow through a packed bed of finely divided solid.

. It is usually rather difficult to get nitrogen to combine with other elements.

. We could not get this product to polymerise.

, . These properties led him to suggest that they had prepared a novel compound.


1. to make to. :

. made this reaction run at reduced pressure.

, to make , to.

. A given fluid is made to flow very slowly into the reaction vessel.

2. to cause + , , .

:

50 610 3 6 . The application of a pressure of about 50 cm of mercury will cause a drop weighing 610 mg to fall every 36 seconds.

. The decreasing concentration at the maximum causes the band to move relatively faster.

, . This phenomenon causes the peaks emerging by elution from the column to be very asymmetric.

90 , . Heating to about 90 or above can cause trimethyltallium to decompose with explosion.

, . Addition of an ammonium salt to a liquid ammonia solution of trimethyltin sodium causes trimethyltin hydride to separate as a heavy oil.

225. to allow, to enable, to permit . , , ( ) .

:


. High temperatures allowed the reaction to be carried out in 2 hours.

. Reaction rate studies allow a decision to be made concerning the following theoretical mechanisms for the above isomerizations.

, . In all the cases which we have examined the enhancement in the intensity of this band is sufficient to enable conjugation to be recognized.

. Closer examination sometimes permits a series of lines to be extracted from a more complicated pattern.

. The properties may be used to study melting and crystallisation and they enable the calculation of the relative proportions of crystalline and amorphous phases to be made.

. Since that time the full mathematical analysis of many simple hydrocarbons has enabled this absorption to be defined with more precision.

. , .

:

, . Thus in certain cases sedimentation velocity method allows one to obtain information on separate components.

() , . Such standard conditions enable one to count all the potentially infective phage particles present in the inoculum.

. The reduction of hydrogen ion serves to limit the cathode potential, and therefore to permit certain electrochemical reactions to occur at the mercury cathode.

16 . . 241


226. . (. ). , , be were, : should, would, could, might to. :

, . It would be an error to say that carbon alone brings about the differences between steel and cast iron.

, , . In such furnaces, though very primitive, they would be able to have at the end of the day a lump of iron as much as ten pounds.

, , . . The iron-maker would call such substances as sulphur and phosphorus impurities in the iron ore. They would not be desired for various reasons.

, , :

1) , , , , , , : , , (. 227);

2) , (. 228);

3) (. 230).

227. , , , , . : to advise, to demand, to wish, to desire, to insist, to order, to propose, to request, to require, to recommend, to suggest, to want, it is necessary, it is important, it is essential, it is desirable, it is required.

:

, . demanded that they should do it.





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