Bridged Manganese Complex Production via pH-Shift Oxidation
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Solution Overview
Problem
Current methods for producing sparingly soluble, crystalline metal complexes used as bleach catalysts face challenges such as low space-time yields, high solvent consumption, and contamination with by-products, making them inefficient for industrial-scale production.
Innovation Solution
A method involving a concentrated aqueous reaction mixture where a metal salt is reacted with an organic ligand in water, oxidized at elevated pH, and then treated with a counterion to precipitate the complex, eliminating the need for organic solvents and additional purification steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional production methods using aqueous-alcoholic media are used, then the manganese complex can be produced, but the space-time yield is low and large amounts of solvent must be evaporated
Solution Approach 1:
The patent changes the solvent system from aqueous-alcoholic media to concentrated aqueous media, and adjusts the pH parameter during different stages of the reaction. By maintaining pH ≥ 12 during oxidation and then adjusting to pH 7-9 for isolation, the patent achieves both high productivity and energy efficiency without requiring large-scale solvent evaporation
Solution Approach 2:
The patent applies different pH conditions to different stages of the process: highly alkaline conditions (pH ≥ 12) during oxidation to prevent manganese oxide precipitation and maintain high reaction efficiency, then moderate conditions (pH 7-9) during isolation to enable complex precipitation. This localized optimization of pH parameters resolves the contradiction between productivity and energy consumption
2Manufacturing precision
If the reaction is carried out in concentrated aqueous media with controlled pH, then high-purity product with high space-time yield is achieved, but the process complexity increases
Solution Approach 1:
The patent performs preliminary oxidation in concentrated aqueous media under controlled pH conditions before isolation, ensuring that the complex forms with high purity and minimal by-products. This preliminary optimization of reaction conditions eliminates the need for additional purification steps, resolving the contradiction between manufacturing precision and process complexity
Solution Approach 2:
The patent extracts the complex from the reaction mixture by adjusting pH to 7-9, causing the complex to precipitate while leaving impurities in solution. This selective extraction achieves high product purity through a simple pH adjustment and filtration process, rather than requiring complex multi-step purification procedures
3Productivity
If manganese(II) salt is oxidized at pH ≥ 12, then the desired manganese(III/IV) complex is formed, but manganese oxides are formed as by-products requiring filtration
Solution Approach 1:
The patent optimizes the pH parameter to be ≥ 12 during oxidation, which maintains high oxidation efficiency while preventing excessive manganese oxide precipitation. The high pH ensures rapid and complete oxidation of manganese(II) to manganese(III/IV) while keeping the by-product formation manageable and the complex soluble, resolving the contradiction between productivity and harmful by-products
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method achieves high-purity, high-yield production of metal complexes with minimal by-product contamination, enabling efficient industrial-scale production and use in detergents and cleaners.
Implementation Method 1
oxidation of the coordination compound from step a) with an oxidizing agent, where at the same time a pH from 11 to 14 and preferably 12 to 14 is maintained, for converting the metal M from the divalent state to the tri- and/or tetravalent state
Implementation Method 2
addition of a salt of the formula MezYq... and the complex is precipitated out and isolated
Data Source
AI summary
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).