Photochemical Separation of Metal Complexes via Light-Induced Electron Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for separating metal ions, such as lanthanide and actinide ions, often require harsh redox reagents, high applied potentials, or rely on solubility and binding affinity, which can be inefficient and costly.
Innovation Solution
The use of photoinduced electron transfer reactions to selectively excite and chemically transform metal complexes, allowing for separation based on unique absorption spectra and ligand transformations, rather than metal ion properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electrochemical reactions or chemical redox reactions are used to generate and separate oxidized/reduced products, then separation of metal ions can be achieved, but harsh redox reagents and high applied potentials are required which lead to degradation of solvent and electrodes
Solution Approach 1:
The patent replaces electrochemical and chemical redox reactions with photoinduced electron transfer reactions. Instead of using harsh redox reagents and high applied potentials (electrochemical/mechanical approach), the invention uses light energy to directly induce electron transfer from a sacrificial donor to the metal complex, achieving separation under milder conditions without degrading solvent or electrodes
Solution Approach 2:
The patent changes the energy input parameter from high applied potentials and harsh chemical reagents to specific wavelength light irradiation. By tuning the light wavelength to match the absorption spectrum of the metal complex, electron transfer is achieved at lower energy input, avoiding the degradation issues associated with harsh electrochemical conditions
2Reliability
If photo-reduction with high-energy irradiation is used to separate metal ions, then separations can be achieved for some rare earths and d-block elements, but high-energy light sources and hazardous acids are required
Solution Approach 1:
The patent replaces high-energy irradiation (150-300 nm) with visible or near-UV light by introducing a sacrificial electron donor that absorbs lower energy light and transfers electrons to the metal complex. This substitution eliminates the need for high-energy light sources and hazardous acids while maintaining separation capability
Solution Approach 2:
The patent introduces a sacrificial electron donor as an intermediary between the light source and the metal complex. The donor absorbs lower energy photons and facilitates electron transfer to the metal ion, acting as a mediator that enables milder reaction conditions while achieving the desired photochemical separation
3Ease of manufacture
If separation methods rely on solubility and binding affinity of metal ions, then separations can be performed using chelating agents or ion exchange resins, but the similarity in charge density, size, or binding affinity of metal ions makes separation difficult
Solution Approach 1:
The patent exploits differences in the absorption spectra (color properties) of different metal complexes to achieve selective excitation. By tuning the light wavelength to match the absorption maximum of a specific metal complex, selective electron transfer and separation are achieved, overcoming the limitations of methods that rely on similar binding affinities
Solution Approach 2:
The patent changes the separation basis from physical/chemical properties (solubility, binding affinity, charge density) to optical properties (absorption spectrum). This parameter change enables selective separation of metal ions with similar physical properties by targeting their unique photophysical characteristics
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 enables efficient separation of metal ions under milder conditions, reducing the need for harsh reagents and high potentials, and allows for selective excitation and separation of specific metal complexes.
Implementation Method 1
exposing the liquid to light including one or more wavelengths sufficient to facilitate (i) the formation of an excited state on the first metal complex
Implementation Method 2
an excited state electron transfer to the electron acceptor group of the first metal complex, and (iii) an irreversible chemical reaction of the electron acceptor group
Data Source
AI summary
Provided herein are photochemical separations. The methods herein can include exposing a first metal complex and a second metal complex to light to facilitate an irreversible chemical reaction to form a modified first metal complex. The modified first metal complex then may be separated from the second metal complex. Compositions also are provided.