Study on the Excitation Wavelength Dependence of the Solvation Dynamics in Ionic Liquids
Yoshifumi K
IMURA*, Mako S
HIBUYA, Yoshiro Y
ASAKA, Masakatsu U
ENO(Received October 30, 2014)
Time-resolved fluorescence spectra of 4'-N,N-diethylamino-3-methoxyflavon in several ionic liquids have been measured by using a streak camera at several excitation wavelengths, 370 nm, 400 nm, and 430 nm. In this study, four ionic liquids of imidazolium-based cation with the same anion (bis(trifluoromethanesulfonyl)amide anion ([NTf2]-)) were used. As cations, imidazolium cation with different alkyl chain at the 1st positions of the imidazolium ring were used; 1-ethyl-3-methylimidazolium cation ([EMIm]+), 1-butyl-3-methylimidazolium cation ([BMIm]+), 1-hexyl-3-methylimdazolium cation ([HMIm]+), and 1-octyl-3-methylimidazolium cation ([OMIm]+), respectively. Fluorescence spectra showed a shift to the longer wavelength with the longer delay time after the photo-excitation. The peak position of the fluorescence spectrum at each delay time was evaluated by simulating the spectrum by a log-normal function. It was found that the peak shift of the fluorescence at the early delay time was larger with the shorter excitation wavelength, and in the longer delay time they coincide to the same value. The time profile of the peak position was well simulated by a stretched-exponential function. The average relaxation times evaluated by the integration of the relaxation function were weakly dependent on the excitation wavelength, and they were correlated with the viscosity of the solvent.
.H\ZRUGV: ionic liquid, solvation dynamics, time-resolved fluorescence, excitation wavelength dependence
࣮࣮࢟࣡ࢻ㸸࢜ࣥᾮయ㸪⁐፹ࢲࢼ࣑ࢡࢫ㸪㛫ศゎ⺯ග㸪ບ㉳Ἴ㛗౫Ꮡᛶ
࢜ࣥᾮయ୰࡛ࡢ⁐፹ࢲࢼ࣑ࢡࢫࡢບ㉳Ἴ㛗౫Ꮡᛶࡢ◊✲
ᮌᮧ ెᩥ㸪 ㇂ ┿Ꮚ㸪 ඵᆏ ⬟㑻㸪 ୖ㔝 ṇ
㸯㸬ࡣࡌࡵ
࢝ࢳ࢜ࣥࢽ࢜ࣥࡢ࢜ࣥࡽᵓᡂࡉࢀࡿ
ࡶ㛵ࢃࡽࡎᾮయ≧ែ࡛Ꮡᅾࡍࡿ࢜ࣥᾮయࡣ㸪㟁Ẽ ఏᑟᛶ㸪Ⓨᛶ㸪㞴⇞ᛶ࠸ࡗࡓ≉ᚩࢆᣢࡕ㸪⌧
ᅾᵝࠎ࡞ศ㔝࡛ࡢᛂ⏝◊✲ࡀᒎ㛤ࡉࢀ࡚࠸ࡿ1㸧㸬
࢜ࣥᾮయ࠾࠸࡚ࡣ㸪࢝ࢳ࢜ࣥ࠶ࡿ࠸ࡣࢽ࢜ࣥࡢ ᵓ㐀ࢆኚࡉࡏࡿࡇࡼࡾ㸪≉ᚩⓗ࡞ᾮయᵓ㐀ࢆ
సࡾฟࡋ㸪ࡢ⁐ᾮ࡛ࡣぢࡽࢀ࡞࠸ࡼ࠺࡞ᶵ⬟ࢆᣢ ࡓࡏࡓࡾࡍࡿࡇࡀྍ⬟࡛࠶ࡿ㸬
Fig. 1
ᆺⓗ࡞ ࢜ ࣥ ᾮ య ࡋ ࡚
1-butyl-3-methylimidazoium
hexafluorophosphate ([BMIm]PF
6)
ࡢᏛᵓ㐀ࢆ♧ࡍ㸬 ᅗ♧ࡉࢀࡿࡼ࠺㸪࢝ࢳ࢜ࣥ࠾࠸࡚ࡣ㠀ᴟᛶࡢࣝ࢟ࣝ㙐㛗ࡢ㒊ศ㸪㟁Ⲵࡢᒁᅾࡋࡓ࣑ࢲࢰ
Fig. 1. Typical structure of ionic liquids.
*Department of Science and Engineering, Doshisha University, Kyoto
Telephone: +81-774-65-6561, FAX: +81-774-65-6801, E-mail: [email protected]
࡚࠸ࡿ࠸࠺ᩘࠎࡢドᣐࢆⓎぢࡋࡓ㸬ࡓ࠼ࡤ N,N-diethyl-p-nitroaniline (DMpNA)ࡢືࢫ࣌ࢡࢺ
ࣝࢆඹ㬆࣐ࣛࣥศගἲ࡛ホ౯ࡋࡓࡇࢁ㸪ࡑࡢ
NO
2ఙ⦰ືࡢືᩘࡀඹ㬆࣐ࣛࣥࢆ ᐃࡍࡿ࣮ࣞࢨ
࣮ࡢἼ㛗ࡼࡗ࡚ኚࡍࡿ࠸࠺⌧㇟ࢆぢ࠸ฟࡋ ࡓ5)㸬
DMpNA
ࡣᆺⓗ࡞push-pull
ᆺࡢศᏊ࡛࠶ࡾ㸪 ࡑࡢ྾ࢫ࣌ࢡࢺࣝࡣ⁐፹ࡢᴟᛶࡀࡁࡃ࡞ࡿ㛗Ἴ㛗ഃࢩࣇࢺࡍࡿ㸬࢜ࣥᾮయ୰࡛
DMpNA
ࡢ ඹ㬆࣐ࣛࣥࢆ ᐃࡋࡓࡇࢁ㸪㛗Ἴ㛗ഃ࡛ඹ㬆ࡉࡏ࡚ ᐃࡍࡿ
NO
2ࡢఙ⦰ືࡢືᩘࡀపࡃ࡞ࡾ㸪ඹ㬆ࡽእࢀ࡚ࡃࡿࡧࡁࡃ࡞ࡿࡇࡀศ
ࡗࡓ㸬ࡇࡢ⌧㇟ࡣ㸪≉ᐃࡢ⁐፹≧ែ࠶ࡿศᏊ
ࢆඹ㬆ࡼࡗ࡚㑅ᢥⓗບ㉳ࡋ㸪ࡑࡢືᩘࢆ᳨ฟ
࡛ࡁࡓゎ㔘ࡍࡿࡇࡼࡗ࡚ㄝ᫂ࡉࢀࡓ㸬 ࡉࡽᡃࠎࡣ࢜ࣥᾮయ୰࡛ࡢᏛᛂࡢ㑅ᢥ ᛶࡀ㸪ບ㉳Ἴ㛗ࢆኚࡉࡏࡿࡇࡼࡾไᚚ࡛ࡁࡿ
ࡇࢆⓎぢࡋࡓ
(Fig. 2)
6-8)㸬4'-N,N-diethylamino-3- hydroxyflavon (DEAHF)
ࡣ ᇶ ᗏ ≧ ែ ࠾ ࠸ ࡚ ࡣࣝ࢟ࣝ㙐㛗ࡢ㛗࠸࢜ࣥᾮయࡢ࠺ࡀ㢧ⴭほ ࡉࢀࡓ㸬㛫ศゎ⺯ග ᐃ⌮ㄽゎᯒ9)ࡼࡾ㸪ࡇ ࡢ⌧㇟ࢆヲ⣽᳨ウࡋࡓࡇࢁ㸪ບ㉳≧ែ࠾ࡅࡿ
Normal
యࡢ⁐፹㐣⛬ࡼࡗ࡚ࣉࣟࢺࣥ⛣ືࡢάᛶ࢚ࢿࣝࢠ࣮ࡀኚࡍࡿࡇ㸪ࡋࡓࡀࡗ࡚ບ㉳┤
ᚋࡢ⁐፹≧ែࡢບ㉳Ἴ㛗ࡼࡿ㐪࠸ࡀᛂࡢ࣏
ࢸࣥࢩࣕࣝ㠃ࡁ࡞ᙳ㡪ࢆ࠼࡚࠸ࡿࡇࡀ᫂
ࡽ࡞ࡗࡓ㸬
ᮏ◊✲࡛ࡣ㸪ࡇࡢບ㉳Ἴ㛗ࡢ㐪࠸ࡼࡿึᮇࡢ⁐
፹ ≧ ែ ࡢ 㐪 ࠸ ࢆ ࡼ ࡾ ᫂ ࡽ ࡍ ࡿ ࡓ ࡵ 㸪
DEAHF
㢮ఝࡢศᏊ࡛ࣉࣟࢺࣥ⛣ືࢆ㉳ࡇࡉ࡞࠸ศᏊࢆ㢟ᮦࡋ㸪ࡑࡢ⁐፹ࢲࢼ࣑ࢡࢫࡢບ㉳Ἴ 㛗౫Ꮡᛶࡢ᳨ウࢆ࠾ࡇ࡞࠺ࡇࡋࡓ㸬⁐፹ࢲ
ࢼ࣑ࢡࢫࡣ㸪⁐ᾮ୰⁐ࡅ࡚࠸ࡿศᏊࡀᇶᗏ≧ែ
ࡽບ㉳≧ែගບ㉳ࡉࢀࡓ㝿㸪ศᏊ࿘ࡾࡢ⁐፹ศ Ꮚࡀ⁐㉁ศᏊࡢࡲࢃࡾ࡛Ᏻᐃ࡞ᵓ㐀ࢆࡿࡼ࠺
㐠ືࢆ⾜࠸㸪⁐፹ᵓ㐀ࡀ㛫ⓗኚࡋ࡚࠸ࡃ ࡇࢆゝ࠺
(Fig. 3
ཧ↷)
㸬ບ㉳≧ែࡽࡢ⺯ගࢫ࣌Fig. 2. Excitation wavelength dependence of the steady
state fluorescence of DEAHF in [BMIm][[PF6]. Fig. 3. Schemattic illustration of the solvation dynamics.
ࢡࢺࣝࢆほ ࡍࡿ㸪⁐፹ᵓ㐀ࡀᙧᡂࡉࢀࡿࡘ
ࢀ࡚ບ㉳≧ែࡢ࢚ࢿࣝࢠ࣮ࡀୗࡀࡿࡓࡵ㸪⺯ගࡢ Ἴ㛗ࡀ㛫ࡶప࢚ࢿࣝࢠ࣮ഃ㸪ࡍ࡞ࢃࡕ㛗Ἴ 㛗ഃኚࡋ࡚࠸ࡃᵝᏊࡋ࡚ほᐹࡉࢀࡿ㸬ࣉࣟࢺ
ࣥ⛣ືࢆ㉳ࡇࡍ
DEAHF
ࡣ㸪Normal
యTautomer
యࡢ⺯ගࡀ୧᪉ほ ࡉࢀࡿࡓࡵ㸪ࢫ࣌ࢡࢺࣝࢩࣇࢺࢆヲ⣽ホ౯ࡍࡿࡣ࠶ࡲࡾ㐺ࡉ࡞࠸㸬ࡑࡇ࡛ࣉࣟ
ࢺࣥ⛣ືࢆ㉳ࡇࡉ࡞࠸ศᏊ࡛
Normal
యࡢ⺯ගࢫ࣌ࢡࢺࣝࡢࡳࢆほ ࡍࡿࡇࡼࡾ㸪⺯ගࢫ࣌ࢡࢺࣝ
ࡢ㛫ኚࡢヲ⣽࡞ゎᯒࡽ⁐፹⎔ቃࡀບ㉳Ἴ 㛗ࡼࡗ࡚ࡢࡼ࠺ኚࡍࡿࢆ᫂ࡽࡍࡿ
ࡇࢆ⏬ࡋࡓ㸬ලయⓗࡣ㸪
DEAHF
ࡢࣄࢻࣟ࢟ࢩࣝᇶࢆ࣓ࢺ࢟ࢩᇶ⨨ࡋࡓ
4'-N,N-diethylamino- 3-methoxyflavon (DEAMF)
ࢆ ᐃᑐ㇟ࡋ㸪ࣝ࢟ࣝ㙐㛗ࡢ␗࡞ࡿ㸲✀㢮ࡢ࢜ࣥᾮయ୰࡛㛫ศゎ
⺯ග ᐃࢆ࠾ࡇ࡞࠸⁐፹ࢲࢼ࣑ࢡࢫࢆ᳨ウࡋ ࡓ㸬
㸬 ヨᩱ࠾ࡼࡧᐇ㦂᪉ἲ ヨᩱ
࢜ࣥᾮయࡋ࡚ࡣ
1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([EMIm][NTf
2]), 1-butyl-3-methylimidazolium NTf
2-1([BMIm][NTf
2]), 1-hexyl-3-methylimdazolium NTf
2-1([HMIm][NTf
2]),
࠾ࡼࡧ
1-octyl-3-methylimidazolium NTf
2-1([OMIm]
[NTf
2])
ࢆ ⏝ ࠸ ࡓ(Fig. 4)
㸬[EMIm][NTf
2]
࠾ ࡼ ࡧ[BMIm][NTf
2]
ࡣ㛵ᮾᏛ(
ᰴ)
〇ࡢࡶࡢࢆ㉎ධࡋ㸪[HMIm][NTf
2]
࠾ࡼࡧ[OMIm][NTf
2]
ࡣIloitec
〇ࡢࡶࡢࢆ㉎ධࡋࡓ㸬
[HMIm][NTf
2]
࠾ࡼࡧ[OMIm][NTf
2]
ࡘ࠸࡚ࡣ╔Ⰽࡋ࡚࠸ࡓࡢ࡛㸪ࢭࢺࢽࢺ࡛ࣜࣝᕼ 㔘ᚋ㸪άᛶⅣΰྜࡋ
1
㐌㛫᧠ᢾࡋࡓࡢࡕ㸪ࢪ ࢡ࣓ࣟࣟࢱ࡛ࣥᢳฟࡋ࡚㸪┿✵⇱ࢆ⾜ࡗࡓᚋᐇ㦂⏝ࡋࡓ㸬⁐㉁ศᏊ࡛࠶ࡿ
DEAMF
ࡣ㸪᪤ሗࡢ᪉ ἲ10㸧ᚑࡗ࡚ྜᡂࡋࡓDEAHF
ࢆ࣓ࢺ࢟ࢩࡍࡿࡇࡼࡗ࡚ྜᡂࡋࡓ㸬
ᐇ㦂࠾࠸࡚ࡣࡲࡎ
DEAMF
ࢆ࢜ࣥᾮయ⁐ゎ ࡉࡏ㸪┿✵୍࡚ࣛࣥᬌ௨ୖ┿✵ᘬࡁࢆ⾜ࡗࡓࢧࣥࣉࣝࢆ⏝ពࡋࡓ㸬ྵỈ㔞ࡣ࣮࢝ࣝࣇࢵࢩ࣮࡛ࣕ
ホ౯ࡋ㸪࠸ࡎࢀࡢ࢜ࣥᾮయࡶ
100 ppm
௨ୗ࡛࠶ࡗ ࡓ㸬⏝ពࡋࡓࢧࣥࣉࣝࢆ1 mm
ࡢග㊰㛗ࡢࢭࣝᑒ ධࡋ㸪ᐊ(23
Υ)
࡚ ᐃࢆ⾜ࡗࡓ㸬
㛫ศゎ⺯ග ᐃ
ᐇ㦂⨨ࡢᴫ␎ᅗࢆ
Fig. 5
♧ࡍ㸬ቑᖜࡉࢀࡓࢳ ࢱࣥࢧࣇ࣮ࣞࢨ࣮ࡢᇶᮏἼ(800 nm, 120 fs, 2 mJ)
ࢆ࢜ࣉࢸ࢝ࣝࣃ࣓ࣛࢺࣜࢵࢡࣥࣉ(OPA)
ࡼࡾἼ㛗ኚࡋ㸪
740 nm
ࡽ860 nm
ࡢἼ㛗ࢆⓎ⏕ࡉࡏ㸪ࡑࡢ➨㧗ㄪἼࢆ
BBO
⤖ᬗ࡛సᡂࡋບ㉳ගࡋ࡚⏝ࡋࡓ㸬ࢧࣥࣉࣝࡽⓎ⏕ࡋࡓ⺯ගࢆᨺ≀
㠃㙾࡛㞟ගࡋ㸪࣑࣮ࣛ➼ࡢගᏛ⣔ࢆ㏻ࡋ࡚↔Ⅼ㊥㞳
15 cm
ࡢศගჾ㞟ගࡋ㸪ࢫࢺ࣮ࣜࢡ᳨࣓࡛࢝ࣛฟࡋࡓ㸬࣮ࣞࢨ࣮ࡢ೫ග㠃᳨ฟࡢ೫ග㠃ࡢゅᗘࡣ࣐
ࢪࢵࢡࣥࢢࣝࡋ㸪ᅇ㌿ࡢᐤࢆ㝖ཤࡋࡓ㸬 ᚓࡽࢀࡓࢫࢺ࣮ࣜࢡ⏬ീᑐࡋ࡚ࢩࢫࢸ࣒ࡢἼ㛗 ឤᗘ⿵ṇ㸪㛫㍈⿵ṇ㸪྾ࡢ⿵ṇࢆ࠾ࡇ࡞ࡗࡓ㸬 Ἴ㛗ឤᗘ⿵ṇࡣᶆ‽Ⰽ⣲ࡢ⺯ගࢫ࣌ࢡࢺࣝࢆྠ୍
᮲௳ୗ࡛ ᐃࡍࡿࡇࡼࡾホ౯ࡋࡓ11)㸬㛫㍈ࡢ
⿵ṇࡣ㸪ࣥࢺࣛࢭࣥࡢ࣓ࢱࣀ࣮ࣝ⁐ᾮ࠾ࡼࡧ
C153
ࡢࢩࢡࣟ࣊࢟ࢧࣥ⁐ᾮࡢ⺯ගࢫ࣌ࢡࢺࣝࢆFig. 4. Molecular structure of ionic liquids used in this study.
Fig. 5. Laser system used for the measurement of the time-resolved fluorescence.
ࡍࡿ㸬ᐃᖖ⺯ගࡣບ㉳Ἴ㛗౫Ꮡᛶࡀ࠶ࡲࡾ㢧ⴭ࡛ࡣ
࡞࠸ࡀ㸪ᣑࡋࡓᅗࢆࡳࡿບ㉳Ἴ㛗ࢆ㛗Ἴ㛗ഃ
ࢩࣇࢺࡍࡿࡋࡓࡀࡗ࡚㸪㛗Ἴ㛗ഃᑡࡋࢩࣇࢺࡋ
࡚࠸ࡿࡇࡀࢃࡿ㸬ྠᵝࡢഴྥࡀࡢ࢜ࣥᾮయ
୰࡛ࡶほ ࡉࢀࡓ㸬
⨨ࡀపἼᩘഃࢩࣇࢺࡋ࡚࠸ࡿ㸬ᮏ◊✲࡛⏝ࡋࡓ
ࡢ࢜ࣥᾮయ୰࡛ࡶྠᵝࡢ⤖ᯝࡀᚓࡽࢀࡓ㸬 ບ㉳ᚋࡢྛ้࠾ࡅࡿ⺯ගࡢࣆ࣮ࢡἼ㛗ࢆồ
ࡵࡿࡓࡵ㸪ྛ้࠾ࡅࡿ⺯ගࢫ࣌ࢡࢺࣝࡢ⥺ᙧ 㛵ᩘࢆḟࡢ
log-normal
㛵ᩘ࡛ࣇࢵࢺࡋࡓ㸬ܫሺɋሻ
ߥଷ ൌ ݄ ቆെ ʹ ൜ሺͳ ߙሻ
ߛ ൠ
ଶ
ቇ
ࡇࡇ࡛㸪D
= 2
J(
Q-
QP)/
',
࡛࠶ࡾ㸪hࡣࣆ࣮ࢡࡢ㧗ࡉ㸪 QPࡣࣆ࣮ࢡࡢሙᡤ㸪Jࡣ㠀ᑐ⛠ᛶࡢࣃ࣓࣮ࣛࢱ࣮㸪' ࡣࣂࣥࢻᖜࢆ⾲ࡍ㸬ࣇࢸࣥࢢ㝿ࡋ࡚ࡣࡲࡎࡍ࡚ࡢࣃ࣓࣮ࣛࢱ࣮ࢆືࡋ࡚ྛ้࠾ࡅࡿ᭱
㐺್ࢆỴᐃࡋ㸪ࡑࡢᚋ㠀ᑐ⛠ᛶࡢࣃ࣓࣮ࣛࢱ࣮ࡘ
࠸࡚ࡣྛ࢜ࣥᾮయࡢྛບ㉳Ἴ㛗ࡈᖹᆒ್ࢆ
ࡾ㸪ࡑࡢ್࡛ᅛᐃࡋ࡚ࡑࡢ᮲௳࡛ࡢࢫ࣌ࢡࢺࣝࡢ
ྛ้ࡢࢹ࣮ࢱࡢࣇࢵࢺࢆ⾜ࡗࡓ㸬ᅗ୰ᐇ⥺࡛
ࣇࢵࢺࡢ⤖ᯝࡶ♧ࡋ࡚࠶ࡿࡀ㸪ࡼࡃᐇ㦂⤖ᯝࢆ
⌧ࡋ࡚࠸ࡿࡇࡀࢃࡿ㸬
⁐፹ࢲࢼ࣑ࢡࢫࡢບ㉳Ἴ㛗౫Ꮡᛶ
௨ୖࡢゎᯒࢆࡍ࡚ࡢࢹ࣮ࢱᑐࡋ࡚⾜ࡗ࡚ᚓ
ࡽࢀࡓ⤖ᯝࡽ㸪␗࡞ࡿບ㉳Ἴ㛗࡛ࡢ⺯ගࡢࣆ࣮ࢡ ࡢ㛫ኚࢆࡶࡵ㸪ࡑࢀࡽࢆࡲࡵࡓ⤖ᯝࡢ୍
Fig. 7. Typical example of the time resolved fluorescence spectra in [HMIm][NTf2] at different excitation wavelengths (A) 370 nm, (B) 400 nm, and (C) 430 nm.
Fig. 6. (A)Absorption spectrum and fluorescence spectra at different excitation wavelengths of DEAHF in
[OMIm][NTf2]. (B) Enlarged figure of the fluorescence spectra of (A).
(1)
ࢆ
Fig. 8
♧ࡍ㸬Fig. 8 (A)
ࡣ[EMIm][NTf
2]
୰࡛ࡢ⤖ᯝ㸪
(B)
ࡣ[HMIm][NTf
2]
୰࡛ࡢ⤖ᯝ࡛࠶ࡿ㸬ᅗ♧ࡉࢀࡿࡼ࠺㸪ບ㉳Ἴ㛗ࡼࡗ࡚⺯ගࣆ࣮ࢡࡢ㛫 ኚࡍ࡞ࢃࡕ⁐፹ࢲࢼ࣑ࢡࢫ㐪࠸ࡀ࠶ࡿࡇ
ࡀࢃࡿ㸬ບ㉳ᚋ㛫ࡶ࡞࠸้࡛ࡣ㸪㛗Ἴ㛗ບ㉳
ࡢࣆ࣮ࢡࡢ⨨ࡀ㸪▷Ἴ㛗ഃ࡛ບ㉳ࡋࡓࡶࡢࡼࡾࡶ
ࡼ ࡾ ప ࠸ ࢚ ࢿ ࣝ ࢠ ࣮ ⌧ ࢀ ࡿ 㸬 ࡇ ࡢ ഴ ྥ ࡣ
[EMIm][NTf
2]
ࡼࡾ[HMIm][NTf
2]
ࡢ᪉ࡀ㢧ⴭ࡛࠶ࡿ㸬༑ศ㛫ࡀ⤒㐣ࡋ㸪⁐፹ࢲࢼ࣑ࢡࢫࡀࡍࡿ
㛫㡿ᇦ
(
ᩘࢼࣀࡽ10
ࢼࣀ⛊⛬ᗘ)
࡛ࡣ㸪ࣆ࣮ࢡࡢ⨨ࡣບ㉳Ἴ㛗ࡼࡽࡎ୍ᐃ࡞ࡿ㸬
㐣ཤࡢ◊✲ࡽ࢜ࣥᾮయ࠾ࡅࡿ⁐፹ࢲ
ࢼ࣑ࢡࢫࡣḟࡢࡼ࠺࡞㛵ᩘᙧ࡛ࡼࡃ⌧ࡉࢀࡿࡇ
ࡀ▱ࡽࢀ࡚࠸ࡿ12-14)㸬 ߥሺݐሻ ൌ ߥஶ οߥଵ ൬െ ݐ
߬ଵ൰ οߥଶ ቊെ ൬ݐ
߬ଶ൰ఉቋ
ࡇࡇ࡛Qfࡣ้↓㝈࠾ࡅࡿࣆ࣮ࢡࡢ್㸪'Q1
,
'Q2ࡣࢩࣇࢺࡢࡁࡉ㸪W1,
W2(
W1<<
W2)
ࡣ⦆㛫㸪 Eࡣ⦆㛫ࡢศᕸࢆ⾲ࡍࣃ࣓࣮ࣛࢱ࣮࡛࠶ࡿ㸬୍⯡Eࡀᑠࡉࡃ࡞ࢀࡤ࡞ࡿ⦆㛫ศᕸࡢ࠶
ࡿ㛵ᩘ࡞ࡾ㸪Eࡀ
1
ࡢሙྜࡣ㏻ᖖࡢᣦᩘ㛵ᩘ࡞ࡿ㸬㏿࠸⦆㐣⛬ࡢᐃᩘ
(
W1)
ࡣ࠾ࡼࡑ1 ps
⛬ᗘ࡛࠶ࡾ㸪୍⯡࢝ࢳ࢜ࣥࡸࢽ࢜ࣥࡀ⁐㉁ศᏊࡢ࿘ࡾ
࡛័ᛶⓗ࡞㐠ືࢆ⾜࠺ࡇࡼࡗ࡚⏕ࡌࡿ㐣⛬࡛
࠶ࡿ⪃࠼ࡽࢀ࡚࠸ࡿ㸬୍᪉㸪ᘏᣦᩘ㛵ᩘ࡛⾲ࡉࢀ
ࡿ㐜࠸㒊ศࡣ㸪⁐㉁ศᏊࡢ࿘ࡾࡢ⁐፹ศᏊࡀධࢀ᭰
ࢃࡿࡼ࠺࡞୪㐍㐠ືࡼࡗ࡚ᨭ㓄ࡉࢀ࡚࠸ࡿ⪃
࠼ࡽࢀ࡚࠾ࡾ㸪୍⯡ⓗ࢜ࣥᾮయࡢ⢓ᗘ┦㛵ࢆ
♧ࡍࡇࡀከ࠸㸬
ᅇࡢ ᐃ࡛ࡣ㸪ࢫࢺ࣮ࣜࢡ࣓࢝ࣛࡢ㛫ศゎ⬟
ࡢไ㝈ࡼࡾ㸪
1
ࣆࢥ⛊௨ୗࡢ㏿࠸㛫㡿ᇦ࡛ࡢࢲࢼ࣑ࢡࢫࢆホ౯ࡍࡿࡇࡀ࡛ࡁ࡞ࡗࡓࡢ࡛㸪ᐇ 㦂⤖ᯝࡢホ౯࠶ࡓࡗ࡚ࡣᣦᩘ㛵ᩘࡢ㒊ศࢆ┬࠸
ࡓᘧ
(3)
ࢆ⏝࠸࡚ゎᯒࢆ⾜ࡗࡓ㸬 ߥሺݐሻ ൌ ߥஶ οߥଶ ቊെ ൬ݐ߬ଶ൰ఉቋ
Fig. 8
ࡢ⥺ࡀᐇ㦂⤖ᯝࢆ᭱㐺ࡋࡓ᭤⥺ࢆ⾲ࡍ㸬ᅗ♧ࡉࢀࡿࡼ࠺㸪ᐇ㦂⤖ᯝࢆࡼࡃ⌧ࡍࡿࡇࡀ ศࡗࡓ㸬
ゎᯒ⤖ᯝࡽḟᘧࡼࡾྛ࢜ࣥᾮయ୰࡛ࡢᖹ ᆒࡢ⁐፹㛫ࢆィ⟬ࡋࡓ㸬
߬ୟ୴ୣ㸻 ݁ஶ ିሺ௧ ఛΤ మሻഁ݀ݐ
Fig. 9
ᅇ ᐃࡋࡓ࢜ࣥᾮయ୰࡛ࡢࡑࢀࡒࢀࡢᖹᆒࡢ⁐፹㛫Waveࢆ⁐፹ࡢ⢓ᗘKᑐࡋ࡚ࣉࣟ
ࢵࢺࡋࡓ⤖ᯝࢆ♧ࡍ㸬ࡇࡇ࡛ࡣ
400 nm
࡛ບ㉳ࡋࡓ Fig. 9. Average solvation time of DEAMF at the excitation wavelength of 400 nm in various ILs.Fig. 8. Time shift of the fluorescence peak position at different excitation wavelengths in (A)[EMIm][NTf2] and (B)[HMIm][NTf2].
(2)
(3)
(4)
⤖ᯝࢆ♧ࡋ࡚࠶ࡿ㸬ᅗ♧ࡉࢀࡿࡼ࠺㸪ᖹᆒࡢ⁐
፹㛫ࡣࡇࢀࡲ࡛ࡢሗ࿌ྠᵝ࢜ࣥᾮయࡢ
⢓ᗘᑐࡋ࡚ࡰ⥺ᙧ౫Ꮡࡋ࡚࠸ࡿ12,13)㸬ࡇࡢࡇ
ࡣ㸪㐜࠸㐣⛬ࡢ⁐፹ࢲࢼ࣑ࢡࢫࡀ⁐፹ศᏊࡢ ୪㐍㐠ື㛵ಀࡋ࡚࠾ࡾ㸪୍⯡ⓗ࡞୪㐍㐠ືࡢࢲ
ࢼ࣑ࢡࢫࡀ⢓ᗘࡢ㏫ᩘẚࡍࡿ⪃࠼ࢀࡤ⌮ゎ ࡍࡿࡇࡀ࡛ࡁࡿ㸬
ບ㉳Ἴ㛗౫Ꮡᛶࡣ㸪Fig. 8ࡳࡽࢀࡿࡼ࠺ᅇ ࡢ ᐃ࡛ࡣึᮇࡢࢩࣇࢺࡢࡁࡉ㢧ⴭ࠶ࡽࢃ
ࢀ࡚࠸ࡿࡇࡀࢃࡿ㸬ࡇࢀࢆᐃ㔞ⓗ࠶ࡽࢃࡍࡓ
ࡵḟࡢࡼ࠺࡞㔞ࢆィ⟬ࡋࡓ㸬
οߥሺݐ ൌ ͲǤͲͳሻ ൌ ߥሺݐ ൌ ͲǤͲͳሻ െ ߥஶ
ࡍ࡞ࢃࡕοߥሺݐ ൌ ͲǤͲͳሻࡣ㸪ບ㉳ᚋ10 ps࠾ࡅࡿࣆ
࣮ࢡ⨨⦆ᚋࡢࣆ࣮ࢡ⨨ࡢᕪࢆ⾲ࡍ㸬ࡇࡢ್
ࢆ✀ࠎࡢ࢜ࣥᾮయࡘ࠸࡚ບ㉳Ἴ㛗ᑐࡋ࡚ࣉ
ࣟࢵࢺࡋࡓ⤖ᯝࢆFig. 10♧ࡍ㸬ᅗ♧ࡉࢀࡿࡼ
࠺㸪ึᮇࡢࢩࣇࢺ㔞ࡢບ㉳Ἴ㛗౫Ꮡᛶࡣ࢜ࣥᾮ యࡢࣝ࢟ࣝ㙐㛗ࡀ㛗࠸࠺ࡀࡼࡾ㢧ⴭ࡛࠶ࡿ㸬ࡇ ࡢࡇࡣ㸪࢜ࣥᾮయࡢᆒ୍ᛶࡣࣝ࢟ࣝ㙐㛗ࡀ 㛗࠸࠺ࡀ㢧ⴭほ ࡉࢀࡿࡇࢆ♧ࡋ࡚࠾ࡾ㸪ᑟ ධ㒊ศ࡛㏙ࡓᏛᛂࡢ㑅ᢥᛶࡀࣝ࢟ࣝ㙐㛗 ࡢ㛗ࡉ౫Ꮡࡋ࡚࠸ࡿ⌧㇟Ⰻ࠸┦㛵ࢆ♧ࡍࡇ
ࡀ᫂ࡽ࡞ࡗࡓ㸬
⤖ㄽ
ࡇࡇ࡛ࡣ㸪࢜ࣥᾮయࡢ⁐፹ᵓ㐀ࡢᆒ୍ศᕸ
ࢆ᫂ࡽࡍࡿࡓࡵ㸪㛫ศゎ⺯ගࢫ࣌ࢡࢺࣝࡢ
ࡅࡿ⁐፹ࡢ⎔ቃࡢ㐪࠸ࢆࡼࡾヲ⣽᫂ࡽࡍ
ࡿࡣ㸪ṧᛕ࡞ࡀࡽᮏ ᐃ࡛⏝࠸ࡓࢫࢺ࣮ࣜࢡ࣓࢝
࡛ࣛࡣ༑ศ࡛࠶ࡾ㸪ࡼࡾ㧗࠸㛫ศゎ⬟ࢆࡶࡗࡓ ᐃ᪉ἲࡢ㐺⏝ࡀᚲせ࡛࠶ࡾ㸪⌧ᅾග࣮࢝ࢤ࣮ࢺἲ
ࡼࡿ㉸㧗㏿㛫ศゎ ᐃࡢ᳨ウࢆ㐍ࡵ࡚࠸ࡿ㸬
ᮏ◊✲ࡣ୍㒊㸪⌮ᕤᏛ◊✲ᡤ◊✲ຓᡂ㔠ࡼࡗ࡚
⾜ࢃࢀࡓ㸬ࡇࡇㅰពࢆ⾲ࡍࡿ㸬
ཧ⪃ᩥ⊩
1) ࢜ࣥᾮయ◊✲┘ಟ, ࢜ࣥᾮయࡢᏛ㸫᪂ୡ௦ᾮ యࡢᣮᡓ㸫㸪㸦ၿ㸪ᮾி㸪2012㸧㸬
2 ) A. Triolo, O. Russina, H.-J. Bleif and E. Di Cola,
“Nanoscale Segregation in Room Temperature Ionic Liquids”, J. Phys. Chem. B, 111, 4641-4644 (2007).
3) H. V. R. Annapureddy, H. K. Kashyap, P. M. D. Biase and C. J. Margulis, “What is the Origin of the Prepeak in the X-ray Scattering of Imidazolium-Based Room-Temperature Ionic Liquids?”, J. Phys. Chem. B, 114, 16838-16846 (2010).
4) O. Yamamuro, T. Yamada, M. Kofu, M. Nakakoshi and M.
Nagao, “Hierarchical Structure and Dynamics of an Ionic Liquid 1-Octyl-3-Methylimidazolium Chloride”, J. Chem.
Phys., 135, 054508 (1-7) (2011).
5) Y. Kimura, T. Hamamoto and M. Terazima, “Raman Spectroscopic Study on the Solvation of N, N-Dimethyl-p-nitroaniline in Room-Temperature Ionic Liquids”, J. Phys. Chem. A, 111, 7081-7089 (2007).
6) Y. Kimura, M. Fukuda, K. Suda and M. Terazima, “Excited State Intramolecular Proton Transfer Reaction of 4ƍ-N,N-Diethylamino-3-hydroxyflavone and Solvation Dynamics in Room Temperature Ionic Liquids Studied by Optical Kerr Gate Fluorescence Measurement”, J. Phys.
Chem. B, 114, 11847-11858 (2010).
7 ) K. Suda, M. Terazima and Y. Kimura, “Excitation Wavelength Dependence of Photo-induced Intramolecular Fig. 10. The magnitude of the initial peak shift in various
ionic liquids at different excitation wavelengths.
(5)
Proton Transfer Reaction of 4ƍ-N,N-diethylamino- 3-hydroxyflavone in Various Liquids”, Chem. Phys. Lett., 531, 70-74 (2012).
8) K. Suda, M. Terazima, H. Sato and Y. Kimura, “Excitation Wavelength Dependence of Excited State Intramolecular Proton Transfer Reaction of 4´-N,N-diethylamino- 3-hydroxyflavone in Room Temperature Ionic Liquids Studied by Optical Kerr Gate Fluorescence Measurement”, J. Phys. Chem. B, 117, 12567-12582 (2013).
9) S. Hayaki, Y. Kimura and H. Sato, “Ab initio Study on an Excited-State Intramolecular Proton Transfer Reaction in Ionic Liquid”, J. Phys. Chem. B, 117, 6759-6767 (2013).
10) S. M. Ormson, R. G. Brown, F. Vollmer and W. Rettig,
“Switching between Charge- and Proton-Transfer Emission in the Excited State of a Substituted 3-Hydroxyflavone”, J. Photochem. Photobiol. A, 81, 65-72 (1994).
11) J. A Gardecki and M. Maroncelli, “Set of Secondary Emission Standards for Calibration of the Spectral Responsivity in Emission Spectroscopy”, Appl. Spec., 52, 1179-1189 (1998).
12 ) S. Arzhantsev, N. Ito, M. Heit and M. Maroncelli,
“Solvation Dynamics of Coumarin 153 in Several Classes of Ionic Liquids: Cation Dependence of the Ultrafast Component”, Chem. Phys. Lett., 381, 278-286 (2003).
13) S. Arzhantsev, H. Jin, G. A. Baker and M. Maroncelli,
“Measurement of the Complete Solvation Response in Ionic Liquids”, J. Phys. Chem. B, 111, 4978-4989 (2007).
14) X.-X. Zhang, M. Liang, N. P. Ernsting, and M. Maroncelli,
“The Complete Solvation Response of Coumarin 153 in Ionic Liquids”, J. Phys. Chem. B, 117, 4291-4304 (2013).
![Fig. 8. Time shift of the fluorescence peak position at different excitation wavelengths in (A)[EMIm][NTf 2 ] and (B)[HMIm][NTf 2 ]](https://thumb-ap.123doks.com/thumbv2/123deta/9768652.1852656/5.892.463.775.144.451/time-shift-fluorescence-position-different-excitation-wavelengths-emim.webp)
