Do sitting-atop metalloporphyrin complexes really exist?

INOR 641

Jose Luis Garate Morales, lgarate@reedgroup.ucr.edu, University of California Riverside, Riverside, CA 92521 and Chris A. Reed, chris.reed@ucr.edu, Chemistry Department, University of California at Riverside, Riverside, CA 92521-0403.
The microscopic reverse reaction of the metal insertion reactions into porphyrins is demetallation, usually carried out with aqueous acid. Our strategy to access stable intermediates was to protonate a metalloporphyrin with anhydrous carborane acids, (C6H4Me3)(BC11X5Y6) (Y = H, Cl; Y = Br, Cl,) in a poorly solvating medium. Carborane acids were chosen for their “strong yet gentle” qualities and the good crystallizing properties of their salts. We used 1H NMR spectroscopic to follow the demetallation reaction of ZnTPP using the carborane acids, we observed signals in the negative region of the 1H NMR spectrum, at -4.34 and -4.88 ppm, corresponding to four and two protons respectively. We assign the first of these signals to the H4TPP2+ cation (1) and the second correspond to one different intermediate that will be discussed during the presentation.

 

Bioinorganic Chemistry
7:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Inorganic Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006