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Electronic structure of low-spin six-coordinate iron(III) meso-tetrapropylchlorin complexes

Akira Ikezaki

Department of Chemistry, School of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan

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Jyunpei Ono

Department of Chemistry, School of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan

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Yoshiki Ohgo

Department of Chemistry, School of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan

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Mari Fukagawa

Department of Chemistry, School of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan

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Takahisa Ikeue

Department of Material Science, Interdisciplinary Faculty of Science and Engineering, Shimane University, 1060 Nishikawatsu, Matsue 690-8504, Japan

SPP full member in good standing.

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, and

Mikio Nakamura

Department of Chemistry, School of Medicine, Toho University, Ota-ku, Tokyo 143-8540, Japan

Department of Chemistry, Faculty of Science, Toho University, Funabashi 274-8510, Japan

Research Center for Materials with Integrated Properties, Toho University, Funabashi 274-8510, Japan

Corresponding author.

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https://doi.org/10.1142/S1088424614500576Cited by:2 (Source: Crossref)

Abstract

Low-spin iron(III) tetrapropylchlorins [Fe(TⁿPrC)L₂]^± (L = HIm, 1-MeIm, DMAP, CN^-, 4-CNPy, ^tBuNC) adopt the d_xy-type ground state regardless of the nature of axial ligands. Among the complexes examined, [Fe(TⁿPrC)(^tBuNC)₂]⁺ has shown quite unique spectroscopic properties as described below. (1) ¹H NMR signals were extremely broad as compared with those of other complexes. In particular, 5,20-CH₂(α) signal was too broad to detect. (2) No signals except C_γ were observed in ¹³C NMR spectra. (3) Tetragonal splitting parameter (|Δ|) estimated by the EPR g values at 4.2 K reached as much as 12.4 λ, which is the largest |Δ| value among all the low-spin iron(III) porphyrins and porphyrinoids reported previously. On the basis of these results, we have concluded that [Fe(TⁿPrC)(^tBuNC)₂]⁺ adopts the low-spin iron(III) with (d_xz, d_yz)⁴(d_xy)¹ electronic ground state at 4.2–30 K where the EPR spectra are taken, while it should be expressed as the low-spin Fe(II) chlorin π-radical cation [Fe^II(TⁿPrC^.)(^tBuNC)₂]⁺ at ambient temperature where the NMR spectra are taken.

Dedicated to Professor Nagao Kobayashi on the occasion of his 65th birthday

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References

M. K. Safo et al. , J. Am. Chem. Soc. 114 , 7066 ( 1992 ) . Crossref, Web of Science, Google Scholar
M. K. Safo et al. , J. Am. Chem. Soc 116 , 7760 ( 1994 ) . Crossref, Web of Science, Google Scholar
M. R. Cheesman and F. A. Walker , J. Am. Chem. Soc. 118 , 7373 ( 1996 ) . Crossref, Web of Science, Google Scholar
F. A. Walker et al. , J. Am. Chem. Soc. 118 , 12109 ( 1996 ) . Crossref, Web of Science, Google Scholar
M. Nakamura et al. , J. Am. Chem. Soc. 119 , 6284 ( 1997 ) . Crossref, Web of Science, Google Scholar
S. Wołowiec et al. , Inorg. Chem. 36 , 5761 ( 1997 ) . Crossref, Web of Science, Google Scholar
J. Wojaczyński , L. Latos-Grażyński and T. Głowiak , Inorg. Chem. 36 , 6299 ( 1997 ) . Crossref, Web of Science, Google Scholar
M.-A. Pilard et al. , Inorg. Chem. 36 , 6307 ( 1997 ) . Crossref, Web of Science, Google Scholar
M. Nakamura et al. , Inorg. Chem 37 , 2405 ( 1998 ) . Crossref, Web of Science, Google Scholar
M. Nakamura et al. , Inorg. Chem. 38 , 3857 ( 1999 ) . Crossref, Web of Science, Google Scholar
T. Ikeue et al. , J. Am. Chem. Soc. 122 , 4068 ( 2000 ) . Crossref, Web of Science, Google Scholar
G. Simonneaux et al. , J. Am. Chem. Soc. 122 , 4366 ( 2000 ) . Crossref, Web of Science, Google Scholar
T. Ikeue et al. , Inorg. Chem. 40 , 3423 ( 2001 ) . Crossref, Web of Science, Google Scholar
F. A. Walker, The Porphyrin Handbook 5, eds. K. M. Kadish, K. M. Smith and R. Guilard (Academic Press, San Diego, CA, 2000) pp. 81–183. Google Scholar
F. A. Walker , Inorg. Chem. 42 , 4526 ( 2003 ) . Crossref, Web of Science, Google Scholar
F. A. Walker , Chem. Rev. 104 , 589 ( 2004 ) . Crossref, Web of Science, Google Scholar
M. Nakamura , Coord. Chem. Rev. 250 , 2271 ( 2006 ) . Crossref, Web of Science, Google Scholar
M. Nakamura , Y. Ohgo and A. Ikezaki , J. Inorg. Biochem. 102 , 433 ( 2008 ) . Crossref, Web of Science, Google Scholar
A. Ikezaki , Y. Ohgo and M. Nakamura , Coord. Chem. Rev. 253 , 2056 ( 2009 ) . Crossref, Web of Science, Google Scholar
F. A. Walker, The Porphyrin Handbook 5, eds. K. M. Kadish, K. M. Smith and R. Guilard (Academic Press, San Diego, CA, 2000) pp. 81–183. Google Scholar
M. Nakamura, Y. Ohgo and A. Ikezaki, The Handbook of Porphyrin Science 7, eds. K. M. Kadish, K. M. Smith and R. Guilard (World Scientific, 2010) pp. 1–146. Google Scholar
R.-J. Cheng et al. , J. Am. Chem. Soc. 125 , 6774 ( 2003 ) . Crossref, Web of Science, Google Scholar
J. Conradie and A. Ghosh , J. Phys. Chem. B 107 , 6486 ( 2003 ) . Crossref, Web of Science, Google Scholar
Tetragonal splitting parameter, Δ/λ, was calculated on the basis of g values given in reference 11 . Google Scholar
S. Cai et al. , Inorg. Chem. 45 , 3519 ( 2006 ) . Crossref, Web of Science, Google Scholar
A. Ikezaki et al. , Inorg. Chem. 45 , 6728 ( 2006 ) . Crossref, Web of Science, Google Scholar
G. Simonneaux , M. Kobeissi and L. Toupet , Inorg. Chem. 42 , 1644 ( 2003 ) . Crossref, Web of Science, Google Scholar
M. Kobeissi , L. Toupet and G. Simonneaux , Inorg. Chem. 40 , 4494 ( 2001 ) . Crossref, Web of Science, Google Scholar
G. Simonneaux , M. Kobeissi and L. Toupet , J. Chem. Soc, Dalton Trans. 4011 ( 2002 ) . Crossref, Google Scholar
M. Kobeissi and G. Simonneaux , Inorg. Chim. Acta 343 , 18 ( 2003 ) . Crossref, Web of Science, Google Scholar
G. Simonneaux and M. Kobeissi , J. Chem. Soc., Dalton Trans. 1587 ( 2001 ) . Crossref, Google Scholar
A. Ikezaki , T. Ikeue and M. Nakamura , Inorg. Chim. Acta. 335 , 91 ( 2002 ) . Crossref, Web of Science, Google Scholar
Y. Niibori , A. Ikezaki and M. Nakamura , Inorg. Chem. Commun. 14 , 1469 ( 2011 ) . Crossref, Web of Science, Google Scholar
M. W. Renner et al. , J. Am. Chem. Soc. 113 , 6891 ( 1991 ) . Crossref, Web of Science, Google Scholar
P. A. Connick , K. J. Haller and K. A. Macor , Inorg. Chem. 32 , 3256 ( 1993 ) . Crossref, Web of Science, Google Scholar
L. A. Andersson et al. , Inorg. Chem. 29 , 2278 ( 1990 ) . Crossref, Web of Science, Google Scholar
M. O. Senge , J. Photochem. Photobiol. B 16 , 3 ( 1992 ) . Crossref, Web of Science, Google Scholar
S. Cai , D. L. Lichtenberger and F. A. Walker , Inorg. Chem. 44 , 1890 ( 2005 ) . Crossref, Web of Science, Google Scholar
C. K. Chang and J. Fajer , J. Am. Chem. Soc. 102 , 848 ( 1980 ) . Crossref, Web of Science, Google Scholar
C. K. Chang et al. , Proc. Natl. Acad. Sci. USA 78 , 2652 ( 1981 ) . Crossref, Web of Science, Google Scholar
E. P. Sullivan Jr. and S. H. Strauss , Inorg. Chem. 28 , 3093 ( 1989 ) . Crossref, Web of Science, Google Scholar
D. Chang et al. , Inorg. Chem. 23 , 817 ( 1984 ) . Crossref, Web of Science, Google Scholar
M. Rivera and G. A. Caignan , Anal. Bioanal. Chem. 378 , 1464 ( 2004 ) . Crossref, Web of Science, Google Scholar
J. Mao , Y. Zhang and E. Oldfield , J. Am. Chem. Soc. 124 , 13911 ( 2002 ) . Crossref, Web of Science, Google Scholar
M. Nakamura , A. Ikezaki and M. Takahashi , J. Chin. Chem. Soc. 60 , 9 ( 2013 ) . Crossref, Web of Science, Google Scholar
G. Palmer, Iron Porphyrins, Physical Bioinorganic Chemistry Series 2, eds. A. B. P. Lever and H. B. Gray (Addison-Wesley, Reading, MA, 1983) pp. 43–88. Google Scholar
C. P. S. Taylor , Biochim. Biophys. Acta 491 , 137 ( 1977 ) . Crossref, Web of Science, Google Scholar
Y. Ohgo et al. , Inorg. Chem. 46 , 8193 ( 2007 ) . Crossref, Web of Science, Google Scholar
Y. Ohgo et al. , Chem. Commun. 4590 ( 2006 ) . Crossref, Web of Science, Google Scholar
K. Nakamura et al. , Inorg. Chem. 47 , 10299 ( 2008 ) . Crossref, Web of Science, Google Scholar
Y. Ohgo et al. , Dalton Trans. 41 , 3126 ( 2012 ) . Crossref, Web of Science, Google Scholar
A. V. Astashkin et al. , J. Phys. Chem. A 106 , 74 ( 2002 ) . Crossref, Web of Science, Google Scholar
L. A. Yatsunyk and F. A. Walker , Inorg. Chem. 43 , 4341 ( 2004 ) . Crossref, Web of Science, Google Scholar
M. O. Senge , W. W. Kalisch and S. Runge , Tetrahedron 54 , 3781 ( 1998 ) . Crossref, Web of Science, Google Scholar