TY - JOUR
T1 - Methodology to determine the NMR chemical shifts of carbon atoms with radical character
T2 - A case of low-spin bis(tert-butylisocyanide) complex of (meso-tetrapropylporphyrinato)iron(III)
AU - Niibori, Yuka
AU - Ikezaki, Akira
AU - Nakamura, Mikio
N1 - Funding Information:
This work was supported by the Grant-in-Aid for Scientific Research (No. 22550157 ) from Ministry of Education, Culture, Sports, Science and Technology, Japan .
PY - 2011/9
Y1 - 2011/9
N2 - Paramagnetic metal complexes sometimes exhibit no appreciable 13C NMR signals due to the short relaxation time. By making use of the fast self-exchange electron transfer between paramagnetic [Fe III(TPrP)(tBuNC)2]ClO4 and the corresponding diamagnetic [FeII(TPrP)(tBuNC)2], we have determined the chemical shifts of the carbon atoms that exhibit no signals due to the considerable amount of spin density. We have also determined the spin density of the meso carbon atom in [FeIII(TPrP)( tBuNC)2]ClO4 to be 0.076, which is to our knowledge the largest among all the low-spin iron(III) porphyrin complexes reported previously. This method is applicable to all the low-spin iron(III) porphyrinoids if the corresponding diamagnetic complexes are available.
AB - Paramagnetic metal complexes sometimes exhibit no appreciable 13C NMR signals due to the short relaxation time. By making use of the fast self-exchange electron transfer between paramagnetic [Fe III(TPrP)(tBuNC)2]ClO4 and the corresponding diamagnetic [FeII(TPrP)(tBuNC)2], we have determined the chemical shifts of the carbon atoms that exhibit no signals due to the considerable amount of spin density. We have also determined the spin density of the meso carbon atom in [FeIII(TPrP)( tBuNC)2]ClO4 to be 0.076, which is to our knowledge the largest among all the low-spin iron(III) porphyrin complexes reported previously. This method is applicable to all the low-spin iron(III) porphyrinoids if the corresponding diamagnetic complexes are available.
KW - C NMR
KW - Electron configuration
KW - Iron porphyrin
KW - Self-exchange electron transfer
KW - Spin density
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U2 - 10.1016/j.inoche.2011.05.049
DO - 10.1016/j.inoche.2011.05.049
M3 - Article
AN - SCOPUS:79960843399
VL - 14
SP - 1469
EP - 1474
JO - Inorganic Chemistry Communication
JF - Inorganic Chemistry Communication
SN - 1387-7003
IS - 9
ER -