TY - JOUR
T1 - Substituent and matrix effects on the excited triplet states of 1,4-naphthoquinones
AU - Shimokage, Takuji
AU - Ikoma, Tadaaki
AU - Akiyama, Kimio
AU - Tero-Kubota, Shozo
AU - Yamaji, Minoru
AU - Shizuka, Haruo
PY - 1997/12/4
Y1 - 1997/12/4
N2 - Phosphorescence and TREPR spectra have been measured for 2-methyl-1,4-naphthoquinone (MNQ), 2,3-dimethyl-1,4-naphthoquinone (DMNQ), and 2-methoxynaphthoquinone (MeONQ) in several matrices at low temperatures. The |D| value of ZFS parameter decreases with increasing the electron-donating character of the substituent group. For MNQ, the T1 state is clearly assigned to be 3nπ* in character. The broad phosphorescence spectra and minor effects of the matrix polarity on the ZFS parameters lead to the conclusion that the character of the T1 states are mainly 3ππ* in DMNQ and MeONQ. The T1 states of the present naphthoquinone derivatives have more or less mixed character of the 3nπ* and 3ππ* states.
AB - Phosphorescence and TREPR spectra have been measured for 2-methyl-1,4-naphthoquinone (MNQ), 2,3-dimethyl-1,4-naphthoquinone (DMNQ), and 2-methoxynaphthoquinone (MeONQ) in several matrices at low temperatures. The |D| value of ZFS parameter decreases with increasing the electron-donating character of the substituent group. For MNQ, the T1 state is clearly assigned to be 3nπ* in character. The broad phosphorescence spectra and minor effects of the matrix polarity on the ZFS parameters lead to the conclusion that the character of the T1 states are mainly 3ππ* in DMNQ and MeONQ. The T1 states of the present naphthoquinone derivatives have more or less mixed character of the 3nπ* and 3ππ* states.
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U2 - 10.1021/jp971818i
DO - 10.1021/jp971818i
M3 - Article
AN - SCOPUS:0031553226
VL - 101
SP - 9253
EP - 9256
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
SN - 1089-5639
IS - 49
ER -