Synthesis, characterization, and autoreduction of a highly electron-deficient porphycenatoiron(III) with trifluoromethyl substituents.
The synthesis of the first fluorine-containing iron porphycenes, 2,7,12,17-tetraethyl-3,6,13,16-tetrakis(trifluoromethyl)porphycenatoiron(III) chloride [FePc(EtioCF(3))]Cl and its micro-oxo dimer [FePc(EtioCF(3))](2)O and their characterizations are reported. The crystal structure of [FePc(EtioCF(3))](2)O displays a severe saddled distortion of the porphycene framework due to the steric and electronic effects of the CF(3) substituents. The oxidation and reduction potentials for the micro-oxo dimer are significantly more positive compared to those observed for the reference micro-oxo dimer of the iron porphycenes and porphyrins having no electron-withdrawing substituent. Moreover, the (1)H and (19)F NMR spectra of [FePc(EtioCF(3))](2)O demonstrated that the micro-oxo dimer is readily converted into the monomeric ferrous complex in pyridine-d(5) through autoreduction for 1 day, although the reduction of the reference iron porphycenes and porphyrins are not observed in pyridine. These results indicate that the trifluoromethylated iron porphycene is a highly electron-deficient complex with a pyrrolic macrocycle ligand.
Hayashi
Takashi
T
Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, and PRESTO in Japan Science and Technology Agency, Fukuoka 812-8581, Japan. thayatcm@mbox.nc.kyushu-u.ac.jp
Nakashima
Yuji
Y
Ito
Kazuyuki
K
Ikegami
Takahiro
T
Aritome
Isao
I
Aoyagi
Katsuhiro
K
Ando
Tsutomu
T
Hisaeda
Yoshio
Y