Photochemistry of 2,2'-dinitrodiphenylmethanes: Irradiations in neutral, acidic and alkaline media

1976 ◽  
Vol 29 (4) ◽  
pp. 865 ◽  
Author(s):  
CP Joshua ◽  
PK Ramdas
Keyword(s):  
Sulphuric Acid ◽  
Isopropyl Alcohol ◽  
Major Product ◽  
The Other ◽  
Alkaline Media ◽  
Other Hand ◽  
Acidic And Alkaline Media

Photolysis of 2,2'-dinitrodiphenylmethane (1) in isopropyl alcohol affords dibenzo[c,f][l,2]diazepin-11-one 5-oxide (7) as the major product. Dibenzo[c,f][l,2]diazepin-11-one 5,6-dioxide (6), acridone (8) and 2,2'-dinitrobenzophenone (9) are also formed in the reaction. Irradiation of (1) in ethanolic sulphuric acid on the other hand yields 3-(2'-nitropheny1)-2,l-benzisoxazole (11) as the major product; small amounts of (7), (8) and (9) are also isolated. Photoconversion of (1) in triethylamine and alcoholic triethylamine proceeds very slowly and compounds (7), (8) and (9) only are isolated from the photolysed solution. Some aspects of the mechanism are discussed.

Photochemistry of 2,2'-dinitrodiphenylmethanes. II. Irradiation of 5,5'-dimethyl- 2,2'-dinitrodiphenylmethanes in neutral, acidic and alkaline media

1982 ◽  
Vol 35 (11) ◽  
pp. 2377 ◽  
Author(s):  
M Christudhas ◽  
CP Joshua
Keyword(s):  
Major Product ◽  
The Other ◽  
Alkaline Media ◽  
Plausible Mechanism ◽  
Acidic And Alkaline Media

Photolysis of 5,5'-dimethyl-2,2'-dinitrodiphenylmethanes(1)in propan-2-ol yielded 2,9-dimethyl-11 H-dibenzo[c,f][1,2]diazepin-11-one 5-oxides(2) as the major product. 5-Methyl-3-(5'-methyl-2'- nitrophenyl)-2,1-benzisoxazoles (3), 2,9-dimethyldibenzo[c,f][1,2]diazepin-11-ones (4),2,2'-dinitro-tenzophenones (5), acridinones (6), N-hydroxyacridinones (7), dibenzo[c,f][1,2]diazepin-11-one 5,6-dioxide (8)and 2,2'-dinitrosobenzophenone(9)were also formed in varying amounts. Irradiation of (1) in acidic ethanol afforded benzisoxazoles (3) as the major product. In benzene medium, the major photoproduct of (1) was 2,2'-dinitrobenzophenones (5). Irradiation of (1) in triethylamine afforded dibenzo[c,f][1,2]diazepines (12) also in addition to the other products. A plausible mechanism to account for the formation of various products in these photoreactions is discussed.

III.—On the Reduction of Ferric Iron (1) by Sulphurous Acid and (2) by Zinc Dust

1913 ◽  
Vol 32 ◽  
pp. 12-16
Author(s):  
Alexander Charles Cumming ◽  
E. W. Hamilton Smith
Keyword(s):  
Sulphuric Acid ◽  
Carbonate Rocks ◽  
Ferric Iron ◽  
Zinc Dust ◽  
The Other ◽  
Additional Contribution ◽  
Large Excess ◽  
Other Hand

So many papers have appeared on this subject that some apology seems desirable before making an additional contribution. The amount of published work on reduction with sulphurous acid is in itself an indication that many workers have found difficulties. It has been shown that the reduction does not take place in presence of large excess of hydrochloric or sulphuric acid, but the reduction will still occur while the reaction of the solution is strongly acid. On the other hand, Hillebrand (“Analysis of Silicate and Carbonate Rocks,” U.S. Bulletin, 442, p. 113) states if the solution after addition of sulphite is red in colour, it is too alkaline and acid must be added.

scholarly journals Chemical action that is stimulated by alternating currents

1914 ◽  
Vol 90 (615) ◽  
pp. 26-32
Keyword(s):  
Sulphuric Acid ◽  
Alternating Current ◽  
The Other ◽  
Chemical Action ◽  
Local Circuit ◽  
Low Resistance ◽  
Other Hand ◽  
Continuous Current ◽  
Voltaic Cell

The following experiments were carried out in the year 1905. Taking a simple voltaic cell, consisting of an anode and cathode of zinc and carbon, and an electrolyte of dilute sulphuric acid, it was found that polarisation, which takes place when the cell is joined to a local circuit of low resistance, could be diminished or completely abolished, by passing through the cell an alternating current of suitable value. Fig. 1 illustrates the arrangement of the cell, D, joined up to deliver current through the ampèremeter, B; under these conditions the cell is very quickly polarised, and the continuous current falls to a very low figure. On the other hand, if a suitable strength of alternating current of. say, 100 periods per second is sent through the cell from the leads A, the cell D will be completely depolarised and will give its full current delivery. L is a self-induction and K a capacity to prevent the alternating and continuous currents from flowing in each other's circuit, the only part of the circuit common to both being through the cell.

THE ACETOLYSES OF THE ALPHA AND BETA METHYL D-GLUCOPYRANOSIDE TETRAACETATES

1955 ◽  
Vol 33 (1) ◽  
pp. 148-162 ◽  
Author(s):  
R. U. Lemieux ◽  
W. P. Shyluk ◽  
G. Huber
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Sulphuric Acid ◽  
Reaction Mechanisms ◽  
The Other ◽  
Isotopic Dilution ◽  
Other Hand ◽  
Anomeric Center ◽  
Reaction Routes ◽  
Isotopic Dilution Analysis

The acetolyses of the alpha and beta methyl D-glucopyranoside tetraacetates in 1:1 acetic acid – acetic anhydride 0.5 M with respect to sulphuric acid were followed at 25 °C. by isotopic dilution analysis of products isolated after various intervals of time. The reaction of the α-glucoside was found to proceed mainly with inversion of the anomeric center. On the other hand, the β-glucoside was found to undergo acetolysis with retention of configuration concurrent with anomerization. It was shown that the polarimetric changes observed in the course of the reactions could be satisfactorily accounted for on the basis of these reaction routes. Reaction mechanisms are suggested.

Claisen rearrangement of allyloxyanthraquinones

1979 ◽  
Vol 57 (24) ◽  
pp. 3304-3307 ◽  
Author(s):  
C. M. Wong ◽  
R. Singh ◽  
K. Singh ◽  
H. Y. P. Lam
Keyword(s):  
Claisen Rearrangement ◽  
Major Product ◽  
The Other ◽  
Ene Reaction ◽  
Unusual Behaviour ◽  
Other Hand

Allyloxyanthraquinones showed unusual behaviour during the Claisen rearrangement. Thus, 1-allyloxyanthraquinone 9 rearranged very readily in the presence of benzylamine while 2-allyloxyanthraquinone 13 refused to do rearrangement even under very drastic conditions. On the other hand, 1,2-diallyloxyanthraquinone rearranged with the loss of the 2-allyloxy group as the result of a retro-ene reaction which has not been previously observed while 1,4-di(2′-chloro-2′-propenyloxy)anthraquinone 18 rearranged to give, as a major product, the unsymmetrically substituted anthraquinone 19 which is useful in the synthesis of anthracycline aglycones.

scholarly journals II. Note on the decomposition of sulphuric acid by pentachloride of phosphorus

1856 ◽  
Vol 7 ◽  
pp. 11-15 ◽  
Keyword(s):  
Nitric Acid ◽  
Sulphuric Acid ◽  
Mechanical Mixture ◽  
The Other ◽  
Acid Sulphate ◽  
Other Hand ◽  
Equivalent Quantity

Chemists have long been aware of the fact that some acids unite with bases in one proportion only, others in two or more proportions. Thus a given quantity of nitric acid forms with what is termed its equivalent of potash, a definite nitrate of potash; if less than this equivalent quantity of potash were added to the nitric acid, the product would be a mechanical mixture of the same nitrate of potash with uncombined nitric acid; if more than the equivalent of potash were added, the excess of alkali would remain uncombined. Sulphuric acid, on the other hand, is capable of forming two compounds with potash, and it depends upon the proportions in which the two substances are brought together whether the neutral or acid sulphate is formed.

III. On rubian and its products of decomposition

1853 ◽  
Vol 143 ◽  
pp. 67-107 ◽  
Keyword(s):  
Caustic Soda ◽  
Sulphuric Acid ◽  
Cold Water ◽  
The Other ◽  
General Terms ◽  
Other Hand ◽  
Alkaline Earths

Action of Alkalies and Alkaline Earths on Rubian. In the first part of this paper I have described, in general terms, the effect produced on rubian by alkalies. It is only the fixed alkalies that are capable of effecting the decomposition of rubian. Ammonia produces no perceptible change in a watery solution of this substance, except that of altering its colour from yellow to blood-red. This blood-red colour remains unchanged even after long-continued boiling, and the solution still contains rubian, for on supersaturating the ammonia with acid, the solution again becomes yellow, and not the slightest precipitate is produced. The fixed alkalies, on the other hand, act very differently. On adding caustic soda to a solution of rubian, the colour of the solution first changes to blood-red. On boiling the liquid, however, its colour soon changes again from blood-red to purple. This alteration in colour indicates the formation of alizarine. If the boiling be continued, there is deposited, as the liquid becomes more concentrated, a dark purple powder, which consists mainly of a compound of alizarine and soda, and separates in conse­quence of its insolubility in caustic lye. After the liquid has been boiled for some time, then, provided the quantity of soda employed be sufficiently large, the rubian is entirely decomposed. On now adding sulphuric acid in excess, a quantity of orange- coloured flocks, exactly like those produced by the action of acids on rubian, is pre­cipitated, while the liquid becomes almost colourless. These flocks are separated by filtration and washed with cold water, until the sulphate of soda and sulphuric acid are entirely removed. They now consist mainly of four substances, viz. 1st, Alizarine ; 2ndly, Rubiretine ; 3rdly, Verantine and 4thly, a substance which has not hitherto been observed, and to which I shall give the name of Rubiadine .

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

Life Beyond 1MeV

1980 ◽  
Vol 38 ◽  
pp. 30-33
Author(s):  
K.H. Westmacott
Keyword(s):  
Electron Microscopy ◽  
Past Experience ◽  
The Other ◽  
Good Case ◽  
Other Hand ◽  
The U.S

Life beyond 1MeV – like life after 40 – is not too different unless one takes advantage of past experience and is receptive to new opportunities. At first glance, the returns on performing electron microscopy at voltages greater than 1MeV diminish rather rapidly as the curves which describe the well-known advantages of HVEM often tend towards saturation. However, in a country with a significant HVEM capability, a good case can be made for investing in instruments with a range of maximum accelerating voltages. In this regard, the 1.5MeV KRATOS HVEM being installed in Berkeley will complement the other 650KeV, 1MeV, and 1.2MeV instruments currently operating in the U.S. One other consideration suggests that 1.5MeV is an optimum voltage machine – Its additional advantages may be purchased for not much more than a 1MeV instrument. On the other hand, the 3MeV HVEM's which seem to be operated at 2MeV maximum, are much more expensive.

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