Synthesis of Vinylene-<i>Co,N</i>-Linked Multi(porphyrin)s by the Addition of Free-Base
Porphyrins to a C<sub>2</sub>H<sub>2</sub> Complex of Cobalt(III) Porphyrin and Their Oxidative
Rearrangement to Vinylene-<i>N,N</i>‘-Linked Multi(porphyrin)s
Jun-ichiro Setsune
Hirokazu Takeda
Shoji Ito
Yugo Saito
Yoshihiro Ishimaru
Koji Fukuhara
Yasushi Saito
Teijiro Kitao
Tomohiro Adachi
10.1021/ic970770k.s001
https://acs.figshare.com/articles/journal_contribution/Synthesis_of_Vinylene-_i_Co_N_i_-Linked_Multi_porphyrin_s_by_the_Addition_of_Free-Base_Porphyrins_to_a_C_sub_2_sub_H_sub_2_sub_Complex_of_Cobalt_III_Porphyrin_and_Their_Oxidative_Rearrangement_to_Vinylene-_i_N_N_i_-Linked_Multi_porphyrin_s/3619620
The nucleophilic addition reaction of a pyrrole nitrogen of
free-base porphyrins to a π-complexed acetylene
ligand in a cationic Co<sup>III</sup> porphyrin intermediate afforded
good yields of vinylene-<i>Co,N</i>‘-linked
bis(porphyrin)s,
(Por)Co<sup>III</sup>−CHCH−(<i>N-</i>Por)H<sub>2</sub>.
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-<i>N,N</i>‘-linked
bis(<i>meso</i>-tetraarylporphyrin) with
(OEP)Co<sup>III</sup>(H<sub>2</sub>O)<sub>2</sub>ClO<sub>4</sub>
(OEP: octaethylporphyrin dianion) and acetylene. The tetrakis(porphyrin) proved
to be a 1:1 mixture of <i>C</i><i><sub>i</sub></i>- and
<i>C</i><sub>2</sub>-symmetric
regioisomers. These organometallic Co<sup>III</sup> complexes
underwent facile oxidative migration of the Co-bound vinyl
group to a porphyrin pyrrole nitrogen when treated with
Fe<sup>III</sup> salts or HClO<sub>4</sub> to provide moderate to
good yields
of Co<sup>II</sup> vinylene-<i>N,N</i>‘-linked
multi(porphyrin) complexes.
(Vinylene-<i>N,N</i>‘)bis(porphyrin) free bases
with
combinations of different porphyrins have been obtained by this
procedure. The homobinuclear (2Co<sup>II</sup>,
2Cu<sup>II</sup>,
and 2Zn<sup>II</sup>) and heterobinuclear
(Co<sup>II</sup>Cu<sup>II</sup> and
Co<sup>II</sup>Zn<sup>II</sup>) complexes have been prepared and
characterized
spectroscopically. The single-crystal X-ray analysis of
(CHCH-<i>N,N</i>‘)[(OEP)Co<sup>II</sup>Cl][(TPP)Zn<sup>II</sup>Cl]
(TPP: <i>meso</i>-tetraphenylporphyrin dianion) showed a face-to-face structure with an
average inter-ring separation of 4.39 Å
(triclinic <i>P</i>1̄; <i>Z</i> = 2; <i>a</i> =
14.806(4), <i>b</i> = 18.703(10), <i>c</i> =
13.796(3) Å, α = 97.69(3), β = 99.57(2), γ
=
96.74(3)°).
1998-04-11 00:00:00
nucleophilic addition reaction
2 Zn II
pyrrole nitrogen
organometallic Co III complexes
Co II vinylene
TPP
2 ClO 4
oxidative migration
Fe III salts
porphyrin pyrrole nitrogen
Oxidative Rearrangement
4.39 Å
C 2
H 2 O
CH
OEP
tetraphenylporphyrin dianion
C 2 H 2 Complex
2 Cu II
cationic Co III porphyrin
Co II Zn II
C i
Co II Cu II
HClO 4