Anion recognition by coordinative interactions: metal-amine complexes as receptors
Luigi Fabbrizzi1, Antonio Poggi
1Dipartimento di Chimica, Università di Pavia, 27100 Pavia, Italy. luigi.fabbrizzi@unipv.it
Chemical Society Reviews
|October 3, 2012
Summary
Metal complexes act as sophisticated anion receptors, enabling selective binding in water. Their design allows for geometrical selectivity, offering advantages over organic receptors for anion recognition.
Area of Science:
- Coordination Chemistry
- Supramolecular Chemistry
- Anion Recognition
Background:
- Early coordination complexes (e.g., Werner's) featured inert metal centers and trapped anions, allowing isomer studies.
- Later studies on labile transition metal ions revealed fast, reversible anion interactions with metal-amine cores.
Purpose of the Study:
- To review the design and synthesis of sophisticated anion receptors based on metal complexes.
- To highlight the advantages of metal-containing receptors over organic counterparts for anion recognition.
Main Methods:
- Synthesis of coordinatively unsaturated polyamine metal complexes.
- Design of polyamine frameworks for geometrical selectivity based on anion shape and size.
- Utilizing metal-anion interactions for selective anion binding.
Main Results:
- Metal-containing receptors demonstrate strong metal-anion interactions, effective even in aqueous solutions.
- Different transition metal ions offer varied geometrical preferences, enhancing anion binding selectivity.
- Polyamine metal complexes, including macrocycles and cages, exhibit selective anion binding.
Conclusions:
- Metal-based anion receptors offer significant advantages, including water compatibility and tunable selectivity.
- The design of polyamine frameworks and the choice of metal centers are crucial for achieving specific anion recognition.
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