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Jasmin Chmiel
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Name: Jasmin Chmiel
Diploma / M.Sc degree: Westfälische Wilhelms-Universität Münster, Germany
(July 2006)
PhD Project: Poly-Lewis-Acids Based on Organo-Al- and Ga-Compounds with Poly-Alkyne Backbones
Host-guest systems for ionic species have played an important role in the development in the field of supramolecular chemistry based on non-covalent interactions.
The research of Pederson in 1967 on the complexation of alkali-metal ions by crown ethers initiated the development of many different neutral host species for cations. By contrast, anion receptors have been developed much later. Reasons for this delay include the bigger size of anions and the necessity for the synthesis of larger host molecules, which are able to interact with the ion.
In relation to natural processes, like the transport of sulphate or phosphate anions through cell membranes, which is regulated by neutral anion binding proteins, the synthetical design of this new type of host molecules seems to be a good way to imitate nature. These neutral receptors can be divided into two classes:
With respect to my own research, the cooperative binding of nucleophilic substrates by polydentate Lewis acids is a rapidly emerging area of chemistry. Especially compounds of the group 13 elements have emerged as promising candidates for the molecular recognition of nucleophilic guests.
The characteristic feature in this field of chemistry is the possible combination of a geometrically fixed alkyne skeleton with Lewis-acidic compounds based on aluminium or gallium. The main idea is the possible use of these systems as potential Lewis-base traps and the challenge to find novel rigid alkyne skeletons, which can be organized in a kind of cage to bind ions of different sizes and forms to change their electronic situation and thus their reactivity. Furthermore, it is worthwhile to study and explain how far a variation of the Lewis-acidic functions can influence specific binding to ions.
Jasmin Chmiel
eMail: Jasmin Chmiel