326 Synthesis and Characterization of Novel Face-to-Face Porphyrin

Thursday, November 5, 2009: 4:20 PM
Rio Grande (Camino Real Hotel)
Josmalen M. Ramos , Department of Chemistry, Texas A&M University-Commerce, Commerce, TX
Stephen D. Starnes , Department of Chemistry, Texas A&M University-Commerce, Commerce, TX
Selective anion receptors may be obtained by rational host design. The approach taken centers on the development of hosts that complement the shape and binding motifs of the target anion guest. Selectivity may also be enhanced through design of a host that has a rigid, well defined binding cavity that selects against guests based on size in addition to complementarity. With this in mind, we have synthesized a doubly metallated bis- porphyrin host that complements the shape of linear and spherical guests. The face-to-face porphyrin host is rigid with a well-defined cavity. In this thesis, we will discuss the host 's synthesis and anion recognition properties. The host reported binds anions through cooperative metal coordination and hydrogen bond interactions. The host's recognition properties with various anion guests vary in geometry: spherical (chloride, bromide, and iodide), 'bent' (acetate, nitrite), trigonal planar (nitrate, bicarbonate, and carbonate), tetrahedral (perchlorate, perrhenate, hydrogen sulfate, and dihydrogen phosphate) and neutral nitrogen heterocycles (pyrazine, picoline, L-nicotine, pyridine, and 1, 4 diazabicyclo [2.2.2] octane).