PROCESS FOR THE MANUFACTURE OF HALOGENOBIS(ALKENE)RHODIUM(I) DIMERS OR HALOGENOBIS(ALKENE)IRIDIUM(I) DIMERS

Abstract

A process for the manufacture of a complex of the formula [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 with M = Rh or Ir; Hal = Cl, Br or l; and R.sup.1R.sup.2C═CR.sup.3R.sup.4 = a gaseous mono olefin with 2 to 4 carbon atoms, the process comprising the steps: (1) preparing an aqueous alcoholic solution of a MHal.sub.3 hydrate salt, (2) reacting the dissolved MHal.sub.3 hydrate salt with the gaseous mono olefin R.sup.1R.sup.2C═CR.sup.3R.sup.4 under formation of precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2, (3) optionally, cooling the reaction mixture obtained after conclusion of step (2) down to a temperature in the range of > 0 to 10° C. and keeping it there, and (4) collecting and drying the precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2, wherein the temperature of the reaction mixture during step (2) is kept in a range of 15 to 30° C.

Claims

1. A process for the manufacture of a complex of the formula [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 where M is Rh or Ir; Hal is Cl, Br or I; and R.sup.1R.sup.2C═CR.sup.3R.sup.4 is a gaseous mono olefin with 2 to 4 carbon atoms, the process comprising the steps: (1) preparing an aqueous alcoholic solution of a dissolved MHal3 hydrate salt, (2) reacting the dissolved MHal3 hydrate salt with the gaseous mono olefin under formation of precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 (3) optionally, cooling the reaction mixture obtained after conclusion of step (2) down to a temperature in the range of > 0 to 10° C., and (4) collecting and drying the precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 wherein the temperature of the reaction mixture during step (2) is maintained in a range of 15 to 30° C.

2. The process of claim 1, wherein M is Rh and Hal is Cl.

3. The process of claim 1, wherein R.sup.1R.sup.2C═CR.sup.3R.sup.4 is ethylene.

4. The process of claim 1, wherein during step (1) the MHal.sub.3 hydrate salt is dissolved in water according to a concentration in a range of 2 to 4 mol of M per liter of aqueous solution and further diluted with a water-miscible alcohol according to a concentration ina range of 0.2 to 0.4 mol of M per liter of aqueous alcoholic solution.

5. The process of claim 4, wherein the water-miscible alcohol is selected from methanol, ethanol, isopropanol or any mixture thereof.

6. The process of claim 4, wherein the water-miscible alcohol is methanol.

7. The process of claim 1, wherein the gaseous mono olefinis utilized as a reaction atmosphere .

8. The process of claim 14, wherein the gaseous mono olefinis bubbled at a flow rate in a range of 2 to 3 liter per hour and per liter volume of reactor.

9. The process of claim 1, wherein the gaseous mono olefin is supplied in stoichiometric excess amount during step (2).

10. The process of claim 1, wherein step (2) has a duration in a range of 12 to 24 hours.

11. The process of claim 1, wherein the temperature of the reaction mixture during step (2) is kept in a range of 20 to 25° C.

12. The process of claim 1, wherein step (3) takes place, and wherein the cooled reaction mixture is maintained at > 0 to 10° C. for 2 to 3 hours.

13. The process of claim 5, wherein the water-miscible alcohol is methanol.

14. The process of claim 1, wherein the gaseous mono olefin is actively bubbled into and through the aqueous alcoholic solution.

15. The process of claim 1, wherein during step (1) the MHal.sub.3 hydrate salt is dissolved in water according to a concentration in a range of 2.5 to 3.5 mol of M per liter of aqueous solution and further diluted with a water-miscible alcohol according to a concentration in a range of 0.25 to 0.35 mol of M per liter of aqueous alcoholic solution.

16. The process of claim 1, wherein step (2) has a duration in a range of 15 to 18 hours.

17. A process for the manufacture of a complex of the formula [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 where M is Rh or Ir; Hal is Cl, Br or I; and R.sup.1R.sup.2C═CR.sup.3R.sup.4 is a gaseous mono olefin with 2 to 4 carbon atoms, the process comprising: (1) preparing an aqueous alcoholic solution of a dissolved MHal3 hydrate salt, (2) reacting the dissolved MHal3 hydrate salt with the gaseous mono olefin under formation of precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2, (3) cooling the reaction mixture obtained after conclusion of step (2) down to a temperature in a range of > 0 to 10° C., and (4) collecting and drying the precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2, wherein the temperature of the reaction mixture during step (2) is kept in a range of 15 to 30° C.

18. The process of claim 17, wherein [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 is [RhCl(C.sub.2H.sub.4).sub.2].sub.2.

19. The process of claim 17, wherein step (3) is performed while stirring.

20. The process of claim 17, wherein step (3) is performed while feeding the gaseous mono olefin to the cooling reaction mixture.

Description

[0033] Example 1 was repeated with the only difference that no means for cooling were taken, i.e. the reactor was not placed in a water bath to maintain the temperature at < 25° C. The yield was 638.3 g (67% yield).

[0034] As described above, the present invention relates to the following embodiments 1 to 12:

[0035] Embodiment 1 relates to a process for the manufacture of a complex of the formula [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2 with M = Rh or Ir; Hal = Cl, Br or I; and R.sup.1R.sup.2C═CR.sup.3R.sup.4 = a gaseous mono olefin with 2 to 4 carbon atoms, the process comprising the steps: [0036] (1) preparing an aqueous alcoholic solution of a MHal.sub.3 hydrate salt, [0037] (2) reacting the dissolved MHal.sub.3 hydrate salt with the gaseous mono olefin R.sup.1R.sup.2C═CR.sup.3R.sup.4 under formation of precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2, [0038] (3) optionally, cooling the reaction mixture obtained after conclusion of step (2) down to a temperature in the range of > 0 to 10° C. and keeping it there, and [0039] (4) collecting and drying the precipitated [MHal(R.sup.1R.sup.2C═CR.sup.3R.sup.4).sub.2].sub.2, wherein the temperature of the reaction mixture during step (2) is kept in a range of 15 to 30° C.

[0040] Embodiment 2 relates to the process of embodiment 1, wherein the precious metal M is Rh and Hal is Cl.

[0041] Embodiment 3 relates to the process of embodiment 1 or 2, wherein R.sup.1R.sup.2C═CR.sup.3R.sup.4 is ethylene C.sub.2H.sub.4.

[0042] Embodiment 4 relates to the process of any one of the preceding embodiments, wherein during step (1) the MHal.sub.3 hydrate salt is dissolved in water according to a concentration in the range of 2 to 4 mol of precious metal M per liter of aqueous solution and further diluted with a water-miscible alcohol according to a concentration in the range of 0.2 to 0.4 mol of precious metal M per liter of aqueous alcoholic solution.

[0043] Embodiment 5 relates to the process of embodiment 4, wherein the water-miscible alcohol is selected from methanol, ethanol, isopropanol or any mixture thereof.

[0044] Embodiment 6 relates to the process of embodiment 4 or 5, wherein the water-miscible alcohol is methanol.

[0045] Embodiment 7 relates to the process of any one of the preceding embodiments, wherein the mono olefin gas is utilized as a reaction atmosphere or it is actively bubbled into and through the aqueous alcoholic solution.

[0046] Embodiment 8 relates to the process of embodiment 7, wherein the mono olefin gas flow rate is in the range of 2 to 3 liter per hour and per liter volume of reactor.

[0047] Embodiment 9 relates to the process of any one of the preceding embodiments, wherein the mono olefin is supplied in stoichiometric excess amount during step (2).

[0048] Embodiment 10 relates to the process of any one of the preceding embodiments, wherein step (2) has a duration in the range of 12 to 24 hours.

[0049] Embodiment 11 relates to the process of any one of the preceding embodiments, wherein the temperature of the reaction mixture during step (2) is kept in a range of 20 to 25° C.

[0050] Embodiment 12 relates to the process of any one of the preceding embodiments, wherein step (3) takes place, and wherein the > 0 to 10° C. cool reaction mixture is kept at such temperature for 2 to 3 hours.