Abstract
Presented herein is a study of the acid-induced demetalation of two sterically hindered copper corroles, Cu β-octabromo-meso-triphenylcorrole (Cu[Br(8)TPC]) and β-octakis(trifluoromethyl)-meso-tris(p-methoxyphenyl)corrole (Cu[(CF(3))(8)TpOMePC]). Unlike reductive demetalation, which affords the free-base β-octabromocorrole, demetalation of Cu[Br(8)TPC] under non- reductive conditions (CHCl(3)/H(2)SO(4)) resulted in moderate yields of free-base 5- and 10-hydroxy isocorroles. The isomeric free bases could be complexed to Co(II) and Ni(II), affording stable complexes. Only reductive demetalation was found to work for Cu[(CF(3))(8)TpOMePC], affording a highly saddled, hydrated corrole, H(3)[5-OH,10-H-(CF(3))(8)TpOMePC], where the elements of water had added across C(5) and C(10). Interaction of this novel free base with Co(II) resulted in Co[iso-10-H-[CF(3))(8)TpOMePC], a Co(II) 10-hydro isocorrole. The new metal complexes were all characterized by single-crystal X-ray diffraction analysis and, despite their sterically hindered nature, were found to exhibit almost perfectly planar isocorrole cores.