TY - JOUR
T1 - Photo-induced valence tautomerism in a Co compound
AU - Sato, Osamu
AU - Hayami, Shinya
AU - Gu, Zhong Ze
AU - Takahashi, Kazuyuki
AU - Nakajima, Rie
AU - Seki, Kanako
AU - Fujishima, Akira
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002/6/28
Y1 - 2002/6/28
N2 - Photo-illumination effects have been measured for where LS, tmeda, 3,5-DBSQ and 3,5-DBCat denote low-spin, N,N,N′,N′-tetramethylethylenediamine, 3,5-di-tert-butyl-1,2-semiquinonate and 3,5-di-tert-butyl-1,2-catecholate, respectively. When the title compound was illuminated at 5 K, the magnetization value increased from μeff = 1.7 to 2.3 μB. The absorption spectra after illumination show that the absorption band at around 800 nm, characteristic of the [CoII-HS(tmeda)(3,5-DBSQ)2] state (HS denotes high-spin), increased and the charge transfer band from 3,5-DBCat to 3,5-DBSQ at 2500 nm was reduced. IR spectra show that the C-O stretching peak at 1280 cm-1 is significantly decreased. These results confirm that a photo-induced intra-molecular electron transfer, [CoIII-LS(tmeda)(3,5-DBSQ)(3,5-DBCat)] → [CoII-HS(tmeda)(3,5-DBSQ)2], was induced. The lifetime of the metastable state at 5 K was 175 min.
AB - Photo-illumination effects have been measured for where LS, tmeda, 3,5-DBSQ and 3,5-DBCat denote low-spin, N,N,N′,N′-tetramethylethylenediamine, 3,5-di-tert-butyl-1,2-semiquinonate and 3,5-di-tert-butyl-1,2-catecholate, respectively. When the title compound was illuminated at 5 K, the magnetization value increased from μeff = 1.7 to 2.3 μB. The absorption spectra after illumination show that the absorption band at around 800 nm, characteristic of the [CoII-HS(tmeda)(3,5-DBSQ)2] state (HS denotes high-spin), increased and the charge transfer band from 3,5-DBCat to 3,5-DBSQ at 2500 nm was reduced. IR spectra show that the C-O stretching peak at 1280 cm-1 is significantly decreased. These results confirm that a photo-induced intra-molecular electron transfer, [CoIII-LS(tmeda)(3,5-DBSQ)(3,5-DBCat)] → [CoII-HS(tmeda)(3,5-DBSQ)2], was induced. The lifetime of the metastable state at 5 K was 175 min.
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U2 - 10.1016/S1010-6030(01)00647-5
DO - 10.1016/S1010-6030(01)00647-5
M3 - Article
AN - SCOPUS:0037189116
VL - 149
SP - 111
EP - 114
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
SN - 1010-6030
IS - 1-3
ER -