US3681218A

US3681218A - Photo-chemical production of oximes

Info

Publication number: US3681218A
Application number: US784896A
Authority: US
Inventors: Georges Lucas; Claude Viallet
Original assignee: Societe Nationale des Petroles dAquitaine SA
Current assignee: Societe Nationale des Petroles dAquitaine SA
Priority date: 1967-12-18
Filing date: 1968-12-18
Publication date: 1972-08-01
Anticipated expiration: 1989-08-01
Also published as: CH493935A; DE1815197A1; GB1280990A; FR95327E; BE725585A; NL6818232A; LU57575A1

Abstract

A HIGH-PRESSURE MERCURY VAPOUR DISCHARGE LAMP FOR CARRYING OUT PHOTO-CHEMICAL REACTIONS COMPRISES AN ENVELOPE DEFINING AN ENCLOSED SPACE, THE ENCLOSED SPACE HAVING THEREIN A DOPING MEDIUM COMPRISING AT LEAST ONE HALIDE OF A METAL OF GROUP 3A (SUCH AS YTTRIUM), WITH WHICH THERE MAY BE ASSOCIATED A HALIDE OF A METAL OF GROUP 3B (SUCH AS THALLIUM) AND/OR A HALIDE OF A METAL OF THE LANTHANIDE GROUP (SUCH AS HOLMIUM), THE CONCENTRATION OF THE DOPING MEDIUM BEING FROM 0.002 TO 1 MG./CC. AND PREFERABLY FROM 0.02 TO 0.5 MG/CC.

Description

Int. Cl. B01j l/JO US. Cl. 204-462 XN 8 Claims ABSTRACT OF THE DISCLOSURE A high-pressure mercury vapour discharge lamp for carrying out photo-chemical reactions comprises an envelope defining an enclosed space, the enclosed space having therein a doping medium comprising at least one halide of a metal of Group 3a (such as yttrium), with which there may be associated a halide of a metal of Group 3b (such as thallium) and/ or a halide of a metal of the lanthanide group (such as holmium), the concentration of the doping medium being from 0.002 to 1 'mg./cc. and preferably from 0.02 to 0.5 mg./cc.

BACKGROUND OF THE INVENTION The lamps generally employed for photochemical reactions are mercury vapour discharge lamps.

For many of these reactions, it necessary to eliminate a part of the radiation which is harmful to the main reaction and which is responsible for secondary reactions. These secondary reactions produce deposits on the Walls of the lamp, decrease the yield of the reaction and contaminate the desired product.

In order to obviate these disadvantages, it has been proposed to employ various filters, in some cases constituted by the very nature of the envelope of the lamp, or to use various products which may be interposed in the path of the radiation through the reaction medium.

GENERAL DESCRIPTION OF THE INVENTION The applicants have designed and produced novel lamps exhibiting a predetermined emission spectrum for various photochemical reactions by means of which it is possible to obtain a pure product in an optimum yield.

'It is known that the spectral distribution of the emitted radiation depends essentially upon the nature, upon the quantity and upon the relative proportions of the various elements present in the discharge chamber.

On the other hand, the maximum quantum yield of a particular photochemical reaction may be established'as a function of the main lines of the emission spectrum of a lamp, and the variation of this yield may be established as a function of the concentration and the nature of the reaction medium.

The lamps according to the invention have the advantage of providing a radiation appropriate for the main reactions in an emission range from 3600 to 6000 A. while substantially reducing the radiation which generates secondary reactions. Thus, in one mode of application of these lamps such as the photochemical preparation of the cycloalkanone oximes and in particular of cyclododecanone oxime, greatly improved yields of the order of 3 to 4 moles/kWh. of pure oxime are obtained.

The work carried out by the applicants has involved them in studying, in a first stage, the influence of various addition agents such as halides of Groups 3a and 3b of the Periodic System of the Elements, taken separately or in admixture, and regarded as doping agents, and in 336M218 Patented Aug. 1, 1972 ably from 0.02 to 0.5 mg./ cc.

In accordance with one embodiment of the invention, the lamps always comprise a halide of the Group 3a such as an yttrium halide. They may comprise a mixture of halides of the Groups 3a and 3b such as mixtures of yttrium and indium halides or mixtures of yttrium and thallium halides. Finally, there may be associated with all the previously described doping agents a halide of the lanthanide group such as a holmium halide.

If the mixture of doping agents consists of two halides of metals of the Groups 3a and 311-, for example of yttrium and indium, and of a lanthanide halide, for example holmium, the weight ratio of these halides may be of the order of:

yttrium halide/ indium halide=1/ 2 holmium halide/ yttrium halide: 1/2

Satisfactory results are obtained when the concentration of the holmium halide employed is at most equal to that of the halide of the metal of the Groups 3a and 3b employed in a smaller quantity, and notably when it is between 0.01 and 0.15 mg./cc.

In accordance with one form of construction of these lamps, referred to by way of non-limiting example, there is introduced into the enclosed space of the lamp a mixture of:

Mg./cc. Indium iodide 0.200-0150 Yttrium iodide 0.1000.125 Holmium iodide 0.050.07

If the emission spectra of these lamps are examined,

and for example that of the lamp doped with yttrium and indium iodides, it is found that the relative power of the radiation below 4000 A. is 1.2%, while it is 18% in an undoped mercury vapour lamp.

. Spectral distribution of a lamp containing yttrium and indium iodides:

Relative Power for radiation each wavepower, length in 7\ A. percent watts DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with one embodiment of the invention, the halogen or halogens may be introduced into the lamp in a form in which they are not combined with the elements belonging to the above-designated groups, which are preferably yttrium, indium, thallium and holmium. The introduced halogen must be present therein in a proportion at least equivalent to the number of grammemolecules of the elements of the Groups 3a and 3b and of the lanthanides contained in the lamp.

The following examples, which are given by Way of indication but have no limiting character, will enable the appreciable increases in yield obtained with the lamps according to the invention to be appreciated.

By way of comparison, there are first described examples carried out with lamps containing no iodide of the lanthanide group.

EXAMPLE 1 Into a reactor consisting of a cylindrical Pyrex glass receptacle having an internal diameter of 110 mm. and a height of 200 mm., as described in French Pat. 1,331,478 and provided with an undoped mercury vapour lamp of 25 w. enclosed in a Pyrex glass tube, through which a current of cooling water is passed, are introduced 150 g. of cyclododecane in solution in 150 g. of carbon tetrachloride, and then 50 g. of 99% sulphuric acid. The mixture is stirred and the temperature is maintained between 15 and 20 C. There are introduced 4.3 g. of nitrosyl chloride in solution in carbon tetrachloride and the mercury vapour lamp is ignited.

First after irradiation for 2 hours and again after irradiation for 4 hours, there are introduced 4.3 g. of 10% nitrosyl chloride in carbon tetrachloride (i.e. in all 12.9 g. of nitrosyl chloride).

When the decolouration of the organic solution is complete, which is so after irradiation for 7 hours, the apparatus is stopped, the sulphuric acid layer is separated and the organic solution is then washed with a little 70% sulphuric acid.

The sulphuric acid solutions are combined and poured on to crushed ice. The oxime precipitates, and is filtered, washed with water and, after drying, crystallised from cyclohexane. There are thus obtained 32.9 g. of cyclododecanone oxime, M.P. 132133 C., i.e. a yield of 188 g./kwl1.

EXAMPLE 2 The procedure of Example 1 is followed with a 25-watt lamp doped with yttrium iodide. It is found that it is necessary to introduce 20.1 g. of nitrosyl chloride in 3 lots in order to decolourise the solution. After irradiation for 7 hours, there are obtained 53.9 g. of oxime, which is a yield of 310.20 g. of oxime/kwh.

EXAMPLE 3 The procedure of Example 1 is followed with a lamp doped with a mixture of yttrium and indium iodides.

22 g. of nitrosyl chloride are introduced in 3 lots in order to decolourise the solution, and after irradiation for 7 hours there are obtained 59.5 g. of cyclododecanone oxime, which is a yield of 340 g./kwh.

4 EXAMPLE 4 The procedure of Example 1 is followed with a lamp doped with a mixture of yttrium and thallium iodides.

20.1 g. of nitrosyl chloride are introduced in 3 lots, and after irradiation for 7 hours there are obtained 54.79 g. of cyclododecanone oxime, which is a yield of 319 g. of

oxime per kwh.

EXAMPLE 5 Example 2 is repeated with a lamp comprising a mixture of yttrium and holmium iodides after the addition of 25 grammes of NOCl. There are obtained 66.1 g. of cyclododecanone oxime, which is a yield of 377 g./kwh.

EXAMPLE 6 The procedure of Example 3 is followed, using a lamp comprising holmium iodide in addition to yttrium and indium iodides.

It is necessary to introduce 46.3 g. of nitrosyl chloride, and 126 g. of oxime are obtained, which is an oxime yield of 720 g./kwh.

EXAMPLE 7 EXAMPLE 8 Into a reactor consisting of a cylindrical Pyrex glass receptacle having a diameter of 130 mm. and a height of 350 mm. and provided with a stirrer, a thermometer, and tubes for the introduction and discharge of gas are introduced 600 g. of cyclododecane in solution in 3000 g. of carbon tetrachloride and g. of sulphuric acid. The lamp employed is a 75-watt high-pressure mercury vapour lamp vertically mounted on the axis of the reactor and in a Pyrex glass jacket cooled by a current of Water. The stirrer is started and the lamp is ignited.

A gaseous mixture of nitrosyl chloride and hydrogen chloride is then introduced at a rate of 30 litres per hour at the bottom of the liquid, the mole ratio of NOCl/HCI being 1/8. The temperature of the reaction mixture is maintained between 15 and 20 C. After a reaction period of 6 hours, the irradiation is stopped and the sulphuric acid layer is decanted and poured on the crushed ice, and after neutralisation with dilute caustic soda there are obtained 90 g. of cyclodoecanone oxime, i.e. a yield of 200 g. of oxime per kwh.

EXAMPLE 9 The operation is carried out in the same reactor as in Example 8 with a 75-watt lamp doped with indium and yttrium iodides. 400 g. of 99% sulphuric acid are added and the gaseous nitrosyl chloride/hydrogen chloride mixture is introduced at a rate of 75 litres per hour. After irradiation for 6 hours, 265.5 g. of cyclododecanone oxime are collected, which is a yield of 592.9 g./kwh.

EXAMPLE 10 The procedure of Example 8 is followed with a 75-watt lamp doped with yttrium, indium and holmium iodides. 450 g. of 99% sulphuric acid are introduced and the rate of flow of the nitrosyl chloride/hydrogen chloride mixture is 90 litres per hour. After irradiation for 6 hours, there are obtained 324 g. of cyclododecanone oxime, which is a yield of 720 g./kwh.

EXAMPLE 1 1 Into a reactor identical to that described in Example 9 and provided with the same lamp are introduced 3 litres of cyclohexane. 450 g. of sulphuric acid are added and the gaseous nitrosyl chloride/hydrogen chloride mixture is run in at a speed of 90 litres per hour. After irradiation for 6 hours, there are obtained 216 g. of cyclohexanone oxime, which is a yield of 480 g. kWh.

The following Table I shows the comparisons of yields obtained with lamps according to the invention and undoped lamps, taking as reference the yield obtained in Example 8 (200 g. of oxime per kwh.).

TABLE I Ratio of the yields Cyclododec- Consumpof doped anone tion, lamps to oxime, kwhJkg. undoped Lamps gJkwh. oxime lamp Example 1, Hg 188 5. 3 Example 8, Hg 200 1 Iodides of- Example 2, Y 310 3.2 1.55 Example 5, Y+H0 377 2.6 1.88

Iodides of- Example 3, Y+In 340 2. 9 1. 70 Example 9, Y-I-In 592 1.6 2. 96 Example 6, Y-l-In-l-Ho... 720 1.3 3.60 Example 10, Y+In+Ho 720 1. 3 3. 60

Iodides oi Example 4, Y+T1 319 3.1 1.59 Example 7, Y+T1+Ho 680 1. 4 3. 40

We claim:

1. In a process for carrying out a photochemical reaction, especially a process for the production of oximes by exposing a solution of a cycloal'kane mixed with sulphuric acid to the radiation of a high pressure mercury vapor lamp and adding nitrosyl chloride to said solution, the improvement comprising increasing the yield of the reaction by using a doped high pressure mercury vapor lamp emitting energy having a wavelength lying preponderantly in the range 4000 A. to 6000 A. with at least about 77% of the power of said emitted energy lying in the range 4500 A. to 5500' A. said doped lamp including a doping mixture comprising,

a mixture of at least one Group 3a metal halide, at least one Group 3b metal halide and at least one lanthanide metal halide, the total content of said halides being between about 0.002 mg. and about 1.0 mg. per cubic centimeter.

2. A process according to claim 1 wherein the halide of the metal of Group 3a is in a ratio by weight of 1/ 2 in relation to the concentration of the halide of the metal of Group 3b and the concentration of the halide of the metal of the lanthanide group is in a ratio by weight of 1/2 in relation to the concentration of the halide of the metal of Group 3a.

3. A process according to claim 1 wherein the doping medium contains yttrium iodide.

4. A process according to claim 1 wherein the doping medium contains indium iodide.

5. A process according to claim 1 wherein the doping medium contains holmium iodide.

6. A process according to claim 1 wherein the doping medium contains yttrium iodide, indium iodide and holmium iodide.

7. A process according to claim 1 wherein the photooximation of a cycloalkane'is accomplished.

8. A process according to claim 2 wherein the photooximation of a cycloalkane is accomplished.

References Cited UNITED STATES PATENTS Re. 25,937 12/1965 Ito 204- 162 0 X 3,141,839 7/1964 Metzger et al. 204162 0 X 3,090,739 5/1963 Ito 204-162 0 X 3,309,298 3/ 1967 'Ito et al 204-162 O X 3,312,612 4/1967 Choo 204-162 0 X BENJAMIN R. PA'DGETT, Primary Examiner