Metallated porphyrin-based receptors for anionic guests

ORGN 375

MariJo L. Wienkers1, Jun Wu1, Stephen D. Starnes1, and Dmitry M. Rudkevich2. (1) Department of Chemistry and Biochemistry, New Mexico State University, Box 30001 MSC 3C, Las Cruces, NM 88003, (2) Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX 76019
Due to the multitude of spectroscopic tools available to study porphyrin derivatives, porphyrins are ideal platforms to utilize in receptor design. The porphyrin platform is also ideal for receptor design because it presents a convergent surface that can be functionalized with a variety of recognition elements thus creating a binding pocket for target guests. Metallation of the porphyrin scaffold is one strategy along these lines that is utilized by Nature in the construction of receptors; Heme is a classic example. Surprisingly, the use of metal to guest binding has been a sparingly utilized strategy of synthetic chemists for the construction of artificial receptors. Considering the spectroscopic changes observed when a guest coordinates to a metal recognition site and the strength of this interaction, it is indeed quite surprising that this strategy is not utilized more often in host design. Here we present the synthesis and anion recognition properties of metallated porphyrins for anionic guests where the anion to metal binding interaction is central to the design of the receptors.