Preparation and electrochemical and optical properties of unsymmetrically substituted phthalocyanines with one or two trithiole rings and related symmetric derivatives.
4,5-Bis(benzylthio)-3,6-diethylphthalonitrile (1) was mixed with 4 -t-butylphthalonitrile and then treated with lithium alkoxide in n-hexanol to produce the corresponding unsymmetrically substituted phthalocyanines (2) and (3) with two or four benzylthio groups, respectively. Treatment of phthalocyanine (2) with nickel(II) acetate yielded the corresponding metal complex 2-Ni. Two benzyl groups of 2 and 2-Ni were removed with lithium/THF/ammonia at -78 degrees C under argon, and the dithiolate anions generated were then reacted with elemental sulfur to give monotrithiolophthalocyanines (5) and (5-Ni). A similar treatment of 3 produced bistrithiolophthalocyanine (6). Tetrakistrithiolophthalocyanine (7-Ni) was prepared by complexation of phthalocyanine (4) with nickel(II) acetate, followed by a Birch reduction of the resulting nickel(II) complex (4-Ni), and then sulfurization and cyclization of the octathiolate anions that were generated. The structures of the phthalocyanines were determined by (1)H NMR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. The optical and electrochemical properties of the phthalocyanines were examined by UV-vis absorption spectroscopy and cyclic voltammetry. Treatment of 5, 5-Ni, 6, 7, and 7-Ni with trifluoroacetic acid in chloroform generated positively charged species, which were characterized by UV-vis and/or NMR spectroscopy.
Kimura
Takeshi
T
Center for Instrumental Analysis, Iwate University, Morioka, Iwate 020-8551, Japan. kimura@iwate-u.ac.jp
Kanota
Nagisa
N
Matsui
Kenji
K
Tanaka
Ichiro
I
Tsuboi
Takaaki
T
Takaguchi
Yutaka
Y
Yomogita
Akinori
A
Wakahara
Takatsugu
T
Kuwahara
Shunsuke
S
Nagatsugi
Fumi
F
Akasaka
Takeshi
T