Method for producing bridged manganese complexes of triazacyclononane
The invention relates to a method for producing manganese complex compounds of the general formula (1), wherein M, X, L, z, Y and q are defined as in claim 1 . The method is characterized by the following steps: a) reacting one or more bivalent metal salts with the ligand L in water as the solvent to form a coordination compound from the one or more bivalent metal salt and the ligand L, the one or more bivalent metal salts being selected from bivalent manganese salts and iron salts and at least one bivalent metal salt being a bivalent manganese salt, b) oxidizing the coordination compound of step a) with an oxidant while at the same time maintaining a pH of 11 to 14, to transform the metal M from the bivalent to the trivalent and/or tetravalent form, c) reducing the pH of the reaction mixture to a pH of 4 to 9 and removing any metal oxides or metal hydroxides of the metal M formed and d) adding, at a pH of 4 to 9, a salt of the formula MezYq, wherein Me represents an alkali metal ion, ammonium ion or an alkanol ammonium ion, and Y, z and q are defined as in formula (1).
1. A method for producing a manganese complex compound of the formula (1)
in which
M is selected from the group consisting of manganese in oxidation state III or IV and iron in oxidation state III or IV, where at least one M is a manganese in oxidation state III or IV,
X independently of the others is a coordinating or bridging species, selected from the group consisting of H 2 O, O 2 2− , O 2 − , O 2− , OH − , HO 2 − , SH − , S 2− , SO, Cl − , N 3− , SCN − , N 3 − , RCOO − , NH 2 − and NR 3 , where R is a radical selected from the group consisting of H, alkyl and aryl,
L is 1,4,7-trimethyl-1,4,7-triazacyclononane,
z is an integer from −4 to +4,
Y is a mono- or multivalent countering selected from the group consisting of hexafluorophosphate, perchlorate and tetraphenylborate, which leads to the charge neutrality of the complex, and
q is an integer from 1 to 4,
wherein the process comprises the following steps:
a) reacting at least one divalent metal salt, wherein the at least one divalent metal salt is selected from divalent manganese and iron salts and at least one divalent metal salt is a divalent manganese salt, with the ligand L in water as solvent forming a coordination compound of the at least one divalent metal salt and the ligand L,
b) oxidizing the coordination compound from step a) with an oxidizing agent, where at the same time a pH from 11 to 14 is maintained, for converting the metal M from the divalent state to the tri- and/or tetravalent state,
c) reducing the pH of the reaction mixture of step b) to a pH from 4 to 9, and separating off any metal oxides or hydroxides of the metal M formed and
d) adding a salt of the formula Me z Y q , in which Me is an alkali metal ion, an ammonium ion or an alkanolammonium ion, and Y, z and q are defined above, at a pH from 4 to 9
and where the counterion salt Me z Y q is only introduced into the reaction mixture and reacted after the oxidation step and the removal of the metal oxides and metal hydroxides formed, wherein the at least one divalent metal salt and the ligand compound during the reaction in step a) are present together in an amount of at least 15 parts by weight per 100 parts by weight of water.
2. The method as claimed in claim 1 , further comprising precipitating and isolating the manganese complex compound of the formula (1) from the reaction mixture.
3. The method as claimed in claim 1 , wherein M in the formula (1) is manganese in oxidation state III or IV and the at least one divalent metal salt from step a) is at least one divalent manganese salt.
4. The method as claimed in claim 1 , wherein the at least one divalent metal salt and the ligand compound during the reaction in step a) are present together in an amount of 15 to 55 parts by weight per 100 parts by weight of water.
5. The method as claimed in claim 4 , wherein the at least one divalent metal salt and the ligand compound during the reaction in step a) are present together in an amount of 20 to 50 parts by weight per 100 parts by weight of water.
6. The method as claimed in claim 1 , wherein the oxidizing agent is selected from the group air, pure oxygen, hydrogen peroxide, alkali metal peroxide and alkali metal permanganate.
7. The method as claimed in claim 1 , wherein the counterion Y is hexafluorophosphate.
8. A method for producing a manganese complex compound of the formula (1)
in which
M is selected from the group consisting of manganese in oxidation state III or IV and iron in oxidation state III or IV, where at least one M is a manganese in oxidation state III or IV,
X independently of the others is a coordinating or bridging species, selected from the group consisting of H 2 O, O 2 2− , O 2 − , O 2− , OH − , HO 2 − , SH − , S 2− , SO, Cl − , N 3− , SCN − , N 3 − , RCOO − , NH 2 − and NR 3 , where R is a radical selected from the group consisting of H, alkyl and aryl,
L is 1,4,7-trimethyl-1,4,7-triazacyclononane,
z is an integer from −4 to +4,
Y is a mono- or multivalent counterion selected from the group consisting of hexafluorophosphate, perchlorate and tetraphenylborate, which leads to the charge neutrality of the complex, and
q is an integer from 1 to 4,
wherein the process comprises the following steps:
a) reacting at least one divalent metal salt, wherein the at least one divalent metal salt is selected from divalent manganese and iron salts and at least one divalent metal salt is a divalent manganese salt, with the ligand L in water as solvent forming a coordination compound of the at least one divalent metal salt and the ligand L,
b) oxidizing the coordination compound from step a) with an oxidizing agent, where at the same time a pH from 11 to 14 is maintained, for converting the metal M from the divalent state to the tri- and/or tetravalent state,
c) reducing the pH of the reaction mixture of step b) to a pH from 4 to 9, and separating off any metal oxides or hydroxides of the metal M formed and
d) adding a salt of the formula Me z Y q , in which Me is an alkali metal ion, an ammonium ion or an alkanolammonium ion, and Y, z and q are defined above, at a pH from 4 to 9
and where the counterion salt Me z Y q is only introduced into the reaction mixture and reacted after the oxidation step and the removal of the metal oxides and metal hydroxides formed,
wherein tri-μ-oxobis[(1,4,7-trimethyl-1,4,7-triazacyclononane)manganese(IV)]- bishexafluorophosphate monohydrate is produced.
9. The method as claimed in claim 1 , wherein the crystalline precipitated manganese complex compound of the formula (1) in a further step e), is isolated by filtration or centrifugation.
10. The method as claimed in claim 1 , wherein the oxidizing agent is selected from the group air, pure oxygen, hydrogen peroxide, alkali metal peroxide and alkali metal permanganate in combination with an alkali metal hydroxide.
11. The method as claimed in claim 8 , further comprising precipitating and isolating the manganese complex compound of the formula (1) from the reaction mixture.
12. The method as claimed in claim 8 , wherein M in the formula (1) is manganese in oxidation state III or IV and the at least one divalent metal salt from step a) is at least one divalent manganese salt.
13. The method as claimed in claim 8 , wherein the at least one divalent metal salt and the ligand compound during the reaction in step a) are present together in an amount of at least 15 parts by weight per 100 parts by weight of water.
14. The method as claimed in claim 13 , wherein the at least one divalent metal salt and the ligand compound during the reaction in step a) are present together in an amount of 15 to 55 parts by weight per 100 parts by weight of water.
15. The method as claimed in claim 14 , wherein the at least one divalent metal salt and the ligand compound during the reaction in step a) are present together in an amount of 20 to 50 parts by weight per 100 parts by weight of water.
16. The method as claimed in claim 8 , wherein the oxidizing agent is selected from the group air, pure oxygen, hydrogen peroxide, alkali metal peroxide and alkali metal permanganate.
17. The method as claimed in claim 8 , wherein the counterion Y is hexafluorophosphate.
18. The method as claimed in claim 8 , wherein the crystalline precipitated manganese complex compound of the formula (1) in a further step e), is isolated by filtration or centrifugation.
19. The method as claimed in claim 8 , wherein the oxidizing agent is selected from the group air, pure oxygen, hydrogen peroxide, alkali metal peroxide and alkali metal permanganate in combination with an alkali metal hydroxide.