Peculiar reactivity of face to face biscorrole and porphyrin-corrole with a nickel(II) salt. X-Ray structural characterization of a new nickel(II) bisoxocorrole

New nickel(ii) bisoxocorrole complexes have been synthesized and characteri zed. Two nickel bisoxocorrole isomer complexes are formed in a 1:1 ratio wh en a biscorrole, where an anthracenyl bridge links the two macrocycles in a face to face arrangement, is metallated by nickel in air. Evidence for the insertion of an oxo group at one of the meso positions is given by the X-r ay structural characterization of the Ni-2(BOCA) "cis'' isomer where BOCA i s a bisoxocorrole with an anthracenyl spacer. Conversely, under the same re action conditions no nickel bisoxocorrole is obtained when biphenylene is t he linker of the biscorrole system, the major product of the reaction being a bisnickel bisradical species. Only a small amount of a bisnickel hydroox obiscorrole is isolated in this reaction. A reaction mechanism for both ser ies (anthracenyl and biphenylenyl) is given and a comparison of the behavio r of the biscorrole system with related derivatives is proposed.