Process for separating organometallic compounds and/or metal carbonyls from their solutions in organic media

Abstract

Organometallic compounds and/or metal carbonyls are separated from their solutions in organic media with the aid of semi-permeable membranes made of aromatic polyamides.

What we claim is: 
     
       1. A process for concentrating solutions of organometallic compounds and/or metal carbonyls in an organic media by ultrafiltration or dialysis, said process comprising contacting said solutions with a semi-permeable polyaramide membrane having a retention side and a permeation side opposite said retention side, said membrane being permeable only to said organic media. 
     
     
       2. The process of claim 1 wherein there is a pressure difference between said retention side and said permeation side. 
     
     
       3. The process of claim 2 wherein said pressure difference is greater than an osmotic pressure of said system. 
     
     
       4. The process of claim 2 wherein said difference is 0.2 to 2.0 MPa. 
     
     
       5. The process of claim 1 wherein there is a difference in concentration between said retention side and said permeation side and said separation is carried out by dialysis. 
     
     
       6. The process of claim 5 wherein a flushing solution flows in contact with said permeation side. 
     
     
       7. The process of claim 6 wherein said flushing solution flows countercurrently to said feed. 
     
     
       8. The process of claim 6 wherein said flushing liquid is an organic solvent. 
     
     
       9. The process of claim 6 wherein said flushing solution flows concurrently with said feed. 
     
     
       10. The process of claim 1 wherein said organometallic compound has a carbon atom linked to a first metal directly or through a nitrogen, oxygen, or sulfur atom. 
     
     
       11. The process of claim 10 wherein said first metal is selected from the group consisting of boron, silicon, phosphorous, and Groups IVA, VA, VIA, VIIA, VIIIA, and IB of the Periodic Table. 
     
     
       12. The process of claim 11 wherein said first metal is selected from the group consisting of manganese, cobalt, nickel, palladium, platinum, iridium, and rhodium. 
     
     
       13. The process of claim 1 wherein said organic metallic compound is selected from the group consisting of acetyl acetonate and dimethylglyoximes. 
     
     
       14. The process of claim 1 wherein said metal carbonyl contains at least one additional ligand. 
     
     
       15. The process of claim 14 wherein said additional ligands are selected from the group consisting of hydrogen, olefins, phosphanes, acetates, and benzonitriles. 
     
     
       16. The process of claim 1 wherein said metal carbonyl has a second metal and a carbonyl group, said second metal being linked directly to said carbonyl group. 
     
     
       17. The process of claim 16 wherein said second metal is selected from the group consisting of Groups VIA, VIIA, and VIIIA of the Periodic Table. 
     
     
       18. The process of claim 11 wherein said second metal is selected from the group consisting of iron, cobalt, nickel, ruthenium, rhodium, and iridium. 
     
     
       19. The process of claim 1 wherein said membrane is the product of a polycondensation reaction of an aromatic dicarboxylic acid or derivative thereof with an aromatic diamine. 
     
     
       20. The process of claim 19 wherein said polycondensation reaction is in the presence of a dipolar, aprotic solvent. 
     
     
       21. The process of claim 20 wherein said solvent is N-methyl-2-pyrollidone. 
     
     
       22. Tile process of claim 19 wherein said aromatic dicarboxylic acid or derivative is selected from the group consisting of terephthalic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, and 2,6'-naphthalene dicarboxylic acid. 
     
     
       23. The process of claim 19 wherein said aromatic diamine is selected from the group consisting of p-phenyldiamine, 3,3'-dimethoxybenzidine, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminomethyl) propane, and 1,4-bis(4-aminophenoxy)benzene. 
     
     
       24. The process of claim 19 wherein said membrane is precipitated by adding water after said polycondensation reaction, immersing said membrane isopropanol at least once, and then immersing said membrane in said organic medium. 
     
     
       25. The process of claim 1 wherein said polyaramide membrane is the reaction product of terephthalic acid with p-phenylene diamine, 1,4-bis(4-aminophenoxy) benzene, and/or 3,3'-dimethylbenzidene. 
     
     
       26. The process of claim 1 wherein said polyaramide membrane has a molecular weight of 5,000 to 200,000. 
     
     
       27. The process of claim 26 wherein said molecular weight is 10,000 to 50,000. 
     
     
       28. The process of claim 1 wherein said membrane is integrally asymmetric. 
     
     
       29. The process of claim 1 wherein said membrane comprises a porous support and an active layer. 
     
     
       30. The process of claim 29 wherein said active layer has a thickness of 0.05μ to 5.0μ. 
     
     
       31. The process of claim 29 wherein said membrane has a thickness of 10 to 400μ. 
     
     
       32. The process of claim 31 wherein said membrane has a thickness of 50 to 200μ. 
     
     
       33. The process of claim 1 wherein said membrane comprises hollow-fibers and/or capillaries. 
     
     
       34. The process of claim 1 wherein said membrane is preheated by immersing it in said organic medium. 
     
     
       35. The process of claim 1 which is carried out at a process temperature of 0° to 200° C. 
     
     
       36. The process of claim 35 wherein said process temperature is 40° to 130° C. 
     
     
       37. The process of claim 1 wherein said metal compound comprises not more than 20% by weight of said organic medium. 
     
     
       38. The process of claim 37 wherein said metal compound is 2 to 400 ppm by weight based on said organic medium. 
     
     
       39. The process of claim 1 wherein said feed is at a flow velocity of 0.1 to 10 meters/second. 
     
     
       40. The process of claim 39 wherein said flow velocity is 0.5 to 2.5 meters/second. 
     
     
       41. The process of claim 1 wherein said metal compound has a particle size of at least 50% larger than any other organic compound present. 
     
     
       42. The process of claim 1 wherein said separation is carried out in a plurality of stages. 
     
     
       43. The process of claim 42 wherein said stages are in parallel. 
     
     
       44. The process of claim 42 wherein said stages are in series. 
     
     
       45. The process of claim 1 wherein said metal compound is selected from the group consisting of nickel/aluminum complexes, cobalt/aluminum complexes, phosphate-modified nickel/aluminum alkyl compounds, Pd(CH 3  COO) 2  /P(CH 2  H 5 ) 3  complexes, RuHCl[P(C 6  H 5 ) 3  ] 3 , RhCl[P(C 6  H 5 ) 3  ] 3 , RhCO[P(C 6  H 5 ) 3  ] 2 , Ni[P(p-C 6  H 4  CH 3 ) 3  ] 4  /H + , Ir(COD)[P(C 6  H 11 ) 3  ]Py (COD=1,5-cyclooctane, Py=pyridine), RuCl 2  [P(C 6  H 5 ) 3  ], Ru(BINAP)(ClO 4 ) 2  (BINAP=2,2' bis(diphenylphosphino) 1,1'-binaphthyl), HRhCO[P(C 6  H 5 ) 3  ] 3 , Pd[P(C 6  H 5 ) 3  ] 4 , and complexes containing compounds of the formula ##STR2## wherein X is a sulfonate (SO 3 ) or carboxylate radical (COO); x 1 , x 2 , and x 3  are 0 or 1; R 1  and R 2  are the same or different alkyl radicals having 4 to 12 carbon atoms or aryl or cycloalkyl radicals having 6 to 12 carbon atoms, and R 1  also denotes hydrogen. 
     
     
       46. The process of claim 1 wherein said metal compound is of rhodium and said compound is present in a catalyst amount of 1 to 1000 ppm based on said organic medium. 
     
     
       47. The process of claim 46 wherein said catalyst amount is 3 to 400 ppm. 
     
     
       48. The process of claim 47 wherein said catalyst amount is 20 to 200 ppm. 
     
     
       49. A process for concentrating solutions of non-dissociable organometallic complexes and/or metal carbonyl complexes and excess ligands in an organic media by ultrafiltration or dialysis, said process comprising contacting said solutions with a semi-permeable polyaramide membrane having a retention side and a permeation side opposite said retention side, said membrane being permeable only to said organic media.