title: Synthesis of Vinylene-Co,N-Linked Multi(porphyrin)s by the Addition of Free-Base Porphyrins to a C(2)H(2) Complex of Cobalt(III) Porphyrin and Their Oxidative Rearrangement to Vinylene-N,N'-Linked Multi(porphyrin)s.
abstract: The nucleophilic addition reaction of a pyrrole nitrogen of free-base porphyrins to a pi-complexed acetylene ligand in a cationic Co(III) porphyrin intermediate afforded good yields of vinylene-Co,N'-linked bis(porphyrin)s, (Por)Co(III)-CH=CH-(N-Por)H(2). N-substituted porphyrin free bases are N-vinylated regioselectively at the pyrrole adjacent to the original N-substituted pyrrole in this reaction. Tris- and tetrakis(porphyrin)s have been prepared by reacting a vinylene-N,N'-linked bis(meso-tetraarylporphyrin) with (OEP)Co(III)(H(2)O)(2)ClO(4) (OEP: octaethylporphyrin dianion) and acetylene. The tetrakis(porphyrin) proved to be a 1:1 mixture of C(i)()- and C(2)-symmetric regioisomers. These organometallic Co(III) complexes underwent facile oxidative migration of the Co-bound vinyl group to a porphyrin pyrrole nitrogen when treated with Fe(III) salts or HClO(4) to provide moderate to good yields of Co(II) vinylene-N,N'-linked multi(porphyrin) complexes. (Vinylene-N,N')bis(porphyrin) free bases with combinations of different porphyrins have been obtained by this procedure. The homobinuclear (2Co(II), 2Cu(II), and 2Zn(II)) and heterobinuclear (Co(II)Cu(II) and Co(II)Zn(II)) complexes have been prepared and characterized spectroscopically. The single-crystal X-ray analysis of (CH=CH-N,N')[(OEP)Co(II)Cl][(TPP)Zn(II)Cl] (TPP: meso-tetraphenylporphyrin dianion) showed a face-to-face structure with an average inter-ring separation of 4.39 Å (triclinic P&onemacr;; Z = 2; a = 14.806(4), b = 18.703(10), c = 13.796(3) Å, alpha = 97.69(3), beta = 99.57(2), gamma = 96.74(3) degrees ).
authors.affiliation: Department of Chemistry, Faculty of Science, Kobe University, Nada, Kobe 657, Japan, and Department of Applied Chemistry, College of Engineering, and Department of Chemistry, School of Integrated Arts and Sciences, University of Osaka Prefecture, Sakai, Osaka 591, Japan.
authors.forename: Jun-ichiro
authors.lastname: Setsune Ji
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takeda
authors.forename: Shoji
authors.initials: S
authors.lastname: Ito
authors.forename: Yugo
authors.initials: Y
authors.lastname: Saito
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Ishimaru
authors.forename: Koji
authors.initials: K
authors.lastname: Fukuhara
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Saito
authors.forename: Teijiro
authors.initials: T
authors.lastname: Kitao
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Adachi