(Kobe Univ. ) Takumi Nakano, Ryo Yamamoto, Shunji Kasahara HIGH-RESOLUTION LASER SPECTROSCOPY OF S1-S0 TRANSITION OF NAPHTHALENE: MEASUREMENT OF VIBRATIONALLY EXCITED STATE (Kobe Univ. ) Takumi Nakano, Ryo Yamamoto, Shunji Kasahara

Excited state dynamics IVR ISC absorption fluorescence phosphorescence S0 S1 S2 T1 IC: Internal conversion IVR: Intramolecular vibrational energy redistribution ISC: Intersystem crossing We observe the high-resolution spectrum to understand excited state dynamics.

Measurement of high-resolution spectrum Rotational-resolved high-resolution spectrum in UV-VIS region Assignments of rotational transitions Regularity of rotational lines Molecular constants in high accuracy Anomalies of rotational lines  Line position (energy shift)  Line width (broadening)  Zeeman effect (splitting) Molecular structure Dynamical process

Fluorescence excitation spectrum of naphthalene [1] D. L. Joo et al., J. Mol. Spectrosc. 215, 155 (2011) [2] M. H. Kabir et al., J. Chem. Phys. 119, 3691 (2003) [3] K. Yoshida et al., J. Chem. Phys. 130, 194304 (2009) [4] M. Okubo et al., J. Chem. Phys. 116, 9293 (2002) H. Kato et al., Bull. Chem. Soc. Jpn. 80, 456 (2007) a type b type S1-S0 S2-S0 435 cm-1 [1,2] 1390 cm-1 [3] 1380 cm-1 [3] 2570 cm-1 [3] 0 – 0 [1] 32000 33000 34000 35000 36000 37000 1559 cm-1 [4] Wavenumber / cm-1

Fluorescence excitation spectrum of naphthalene 2122 435 2570 1422 2867 1432 3068 S. M. Beck et al., J. Phys. Chem. 74, 43 (1981) a type b type S1-S0 S2-S0 435 cm-1 [1,2] 1390 cm-1 [3] 1380 cm-1 [3] 1422 cm-1 1432 cm-1 2570 cm-1 [3] 2122 cm-1 3068 cm-1 2866 cm-1 0 – 0 [1] 32000 33000 34000 35000 36000 37000 1559 cm-1 [4] Wavenumber / cm-1

I2 stabilized etalon marker Experimental setup Ar gas & sample Nd3+ :YVO4 laser Ring dye laser I2 stabilized etalon marker I2 cell Doubling cavity PM pulsed nozzle Vacuum chamber liquid N2 trap Photon counter Computer Magnet Slit

Fluorescence excitation spectrum of naphthalene 2122 435 2570 1422 2867 1432 3068 S. M. Beck et al., J. Phys. Chem. 74, 43 (1981) a type b type S1-S0 S2-S0 0 – 0 32000 33000 34000 35000 36000 37000 Wavenumber / cm-1

High-resolution spectrum of 0-0 band 32016 32015 32017 32018 32019 32020 32021 Obs. Calc.(Trot = 40 K, G(FWHM) = 0.0005 cm-1 a-type) Wavenumber / cm-1 Rotational lines were resolved

Molecular constants of 0-0 band S0 (v = 0) 0-0 band (previous work[1]) A / cm-1 0.10405207(16) 0.101470325(51) 0.101462295(60) B 0.041126892(27) 0.040498566(74) 0.040498715(31) C 0.0294838072(80) 0.028955573(79) 0.028955165(22) ΔK 1.87(32)×10-9 ― 1.82(11)×10-9 ΔJK 1.18(22)×10-9 1.751(55)×10-9 ΔJ 5.80(21)×10-10 5.704(80)×10-9 dK 1.37(17)×10-9 3.87(11)×10-9 dJ 1.59(10)×10-10 5.696(53)×10-10 T0 32018.5967(3) 32018.5870(2) band type A Assigned line 1043 3083 Std. Dev. 0.00020 0.00016 [1] D. L. Joo et al., J. Mol. Spectrosc. 215, 155 (2011)

High-resolution spectrum of 0-0 band 32016 32015 32017 32018 32019 32020 32021 Obs. Calc.(Trot = 40 K, G(FWHM) = 0.0005 cm-1 a-type) Wavenumber / cm-1

High-resolution spectrum of 0-0 band qPK- qPK+ J =33 J =32 J =31 Ka =1 Ka =0 32 31 30 2 1 31 30 29 3 2 30 29 28 4 3 Obs. Calc.(40 K) 32016.0 32016.1 32016.2 32016.3 Wavenumber / cm-1

Zeeman effect of 0-0 band H = 0.49 T H = 0 T J = 35 34 33 32 31 30 Wavenumber/ cm-1 32015.85 32015.90 32015.95 32016.00

Zeeman splittings are small. Zeeman effect of 0-0 band Ka= 0 (Kc=J) Zeeman Splitting / MHz J Zeeman splittings are small. Rotational quantum number dependence were found. These effects are observed other vibronic bands. H. Kato et al., Bull. Chem. Soc. Jpn. 80, 456 (2007) M. Okubo et al., J. Chem. Phys. 116, 9293 (2002) D. L. Joo et al., J. Mol. Spectrosc. 215, 155 (2011)

Fluorescence excitation spectrum of naphthalene 2122 435 2570 1422 2867 1432 3068 S. M. Beck et al., J. Phys. Chem. 74, 43 (1981) a type b type S1-S0 S2-S0 2122 cm-1 32000 33000 34000 35000 36000 37000 Wavenumber / cm-1

High-resolution spectrum of 000 + 2122 cm-1 band 34140 34142 34144 34141 34143 34139 34145 Obs. Calc.(Trot = 50 K, G(FWHM)= 0.0005 cm-1 b-type) Wavenumber / cm-1

Molecular constants of vibronic bands S0 (v = 0) 0-0 band 000 + 2122 cm-1 A / cm-1 0.10405207(16) 0.101462295(60) 0.10141594(47) B 0.041126892(27) 0.040498715(31) 0.04047379(48) C 0.0294838072(80) 0.028955165(22) 0.02894462(84) ΔK 1.87(32)×10-9 1.82(11)×10-9 ― ΔJK 1.18(22)×10-9 1.751(55)×10-9 ΔJ 5.80(21)×10-10 5.704(80)×10-9 dK 1.37(17)×10-9 3.87(11)×10-9 dJ 1.59(10)×10-10 5.696(53)×10-10 T0 32018.5870(2) 34141. 9434(2) band type A Assigned line 3083 1232 Std. Dev. 0.00015 0.0008

Energy shift of 000 + 2122 cm-1 band Eob - Ecal

Energy shift of 000 + 2122 cm-1 band Eob - Ecal Eob - Ecal

Fluorescence excitation spectrum of naphthalene 2122 435 2570 1422 2867 1432 3068 S. M. Beck et al., J. Phys. Chem. 74, 43 (1981) a type b type S1-S0 S2-S0 2866 cm-1 32000 33000 34000 35000 36000 37000 Wavenumber / cm-1

High-resolution spectrum of 000 + 2866 cm-1 band 34881 34882 34883 34884 34885 34886 Calc.(Trot = 10 K, G(FWHM) = 0.002 cm-1 a-type) Obs Wavenumber / cm-1

Molecular constants of vibronic bands S0 (v = 0) 0-0 band 000 + 2122 cm-1 000 + 2866 cm-1 A / cm-1 0.10405207(16) 0.101462295(60) 0.10141594(47) 0.101178(10) B 0.041126892(27) 0.040498715(31) 0.04047379(48) 0.040375(11) C 0.0294838072(80) 0.028955165(22) 0.02894462(84) 0.02895155(51) ΔK 1.87(32)×10-9 1.82(11)×10-9 ― ΔJK 1.18(22)×10-9 1.751(55)×10-9 ΔJ 5.80(21)×10-10 5.704(80)×10-9 dK 1.37(17)×10-9 3.87(11)×10-9 dJ 1.59(10)×10-10 5.696(53)×10-10 T0 32018.5870(2) 34141. 943361(51) 34884. 11130(53) band type A Assigned line 3083 1232 90 Std. Dev. 0.00016 0.00081 0.00268

High-resolution spectrum of 000 + 2866 cm-1 band 34881 34882 34883 34884 34885 34886 Calc.(Trot = 10 K, G(FWHM) = 0.002 cm-1 a-type) Obs Wavenumber / cm-1

High-resolution spectrum of 000 + 2866 cm-1 band 34882.8 34882.9 34883.0 34883.1 Calc.(Trot = 10 K, G(FWHM) = 0.002 cm-1 a-type) Obs Wavenumber / cm-1 - Rotational assignment: in progress - Large background signal - Energy shift?

Fluorescence excitation spectrum of naphthalene 2122 435 2570 1422 2867 1432 3068 S. M. Beck et al., J. Phys. Chem. 74, 43 (1981) a type b type S1-S0 S2-S0 3068 cm-1 32000 33000 34000 35000 36000 37000 Wavenumber / cm-1

High-resolution spectrum of 000 + 3068 cm-1 band 35080 35081 35082 35083 35084 35085 Calc.(Trot = 10 K, G(FWHM) = 0.002 cm-1 b-type) Obs Wavenumber / cm-1 - Large background signal - Rotational assignment: difficult.

Rotational assignment Summary 0-0 435 cm-1 2122 cm-1 2866 cm-1 3068 cm-1 Rotational assignment done In progress Difficult Energy shift none Several Many? Too　many? Background small large We determined molecular constants of 0-0 band. The assign of 000 + 2866 cm-1 and 3068 cm-1 band are going on. In the 000 + 2122 cm-1 band, energy shifts were observed. Background signals of 2866cm-1 and 3068 cm-1 band are larger than lower vibrational state