Fumiyuki Ito

National Institute of Advanced Industrial Science and Technology · Research Institute for Environmental Management Technology

In the dense and cold atmosphere of Titan, the presence of C 2 H 4 haze has been confirmed by the observations of satellite explorers. In the present study, an original cryogenic experimental equipment was developed to simulate the low-temperature solid formation of C 2 H 4 in combination with in-situ infrared spectroscopic measurements to understa...

Each olefin (ethylene, trans-1,3-butadiene, isoprene, dimethyl butadiene (DMB)) and ozone molecules were codeposited on a CsI window at cryogenic temperature, and the products of photolysis with ultraviolet–visible light were observed using Fourier-transform infrared spectroscopy. The products of the C2H4–O3 system could be assigned to glyoxal (CHO...

The infrared spectra of acetaldehyde were measured in inert gas matrices (Ar, Kr, and N2). The vibrational features were dependent on the host atoms. In particular, in the C=O stretching region, the fundamental band (ν4) is bifurcated for Ar, whereas it remains isolated for Kr and N2. The bifurcation could be interpreted as a Fermi-diad where host–...

The partition function of a molecule can be obtained by a direct sum-over-states (SOS) calculation using the molecule’s quantum energy levels. These energies can be those obtained by a model fitted to experimental data. For molecules with “exotic” behaviour (such as large amplitude vibrational motion) physically motivated models can be required. Of...

Considerable work has gone into identifying and delineating the effects of quantum monodromy on molecules. Recently this included consideration of transition intensities of the NCNCS molecule using ab initio electric dipole moment functions in the Generalized SemiRigid Bender (GSRB) model [M. Winnewisser et al. PCCP 16, 17373 (2014)]. In that work...

Current methods for the extraction of rhodium carry the highest carbon footprint and worst pollution metrics of all of the elements used in modern technological applications. Improving upon existing methods is made difficult by the limited understanding of the molecular-level chemistry occurring in extraction processes, particularly in the hydromet...

The supermolecule approach has been used to model molecules embedded in a solid argon matrix. The interaction between the guest and the host atoms in the first solvation shell (FSS) are evaluated using density functional calculations while that beyond the FSS is incorporated using ONIOM calculations to extend the results of our previous study [F. I...

The interaction of 2-methyl-1,3-butadiene (isoprene) with a methanol molecule in low-temperature noble gas (Ar, Kr) matrices was investigated using infrared absorption spectroscopy. The spectra were more perplexed than those of the analogous isoprene-H2O complex, and consistent with the complicated potential energy landscape of this complex obtaine...

The interaction of 2-methyl-1,3-butadiene (isoprene) with a H2O molecule in low-temperature noble gas matrices (Ar or Kr) was investigated using infrared absorption spectroscopy. Vibrational peaks arising from 1:1 isoprene-H2O adducts were assigned and compared with the results of quantum chemical calculations. The comparison led to the conclusion...

In this study, the infrared absorption spectra of 2-methyl-1,3-butadiene (isoprene) in noble gas matrices (Ar, Kr, and Xe) has been reported. The vibrational structure observed at cryogenic temperature, in combination with anharmonic vibrational calculations using density functional theory, helped in unambiguously assigning the fundamental modes of...

C has recently been identified as the carrier of some of the diffuse interstellar bands (E.K. Campbell, M. Holz, D. Gerlich, J .P. Maier, Nature 523 (2015) 322–323). Unfortunately, this ion has no dipole moment and therefore no rotational spectrum. We investigate the situation where one of the carbon atoms in this ion is substituted by a ¹³C-atom....

Infrared absorption spectra of formic acid hydrate clusters (HCOOH)m(H2O)n have been measured in noble gas matrices (Ar and Kr). The concentration dependence of the spectra and the comparison with a previous experimental study on HCOOH(H2O) and HCOOH(H2O)2 [Geoge et al., Spectrochim. Acta, Part A 60 (2004) 3225] led to the identification of large c...

Infrared absorption spectra of formic acid clusters (HCOOH)n have been observed in noble gas matrices (Ar, Kr and Xe). The concentration dependence of the spectra and a comparison with the assigned monomeric/dimeric bands has led to the assignment of polymeric species (HCOOH)n (n > 2). From comparisons of these spectra with several sets of DFT calc...

Stable isomers of trifuloroacetic acid (TFA) pentahydrate clusters, TFA-(H2O)5, have been explored by using density functional theory calculations. As done for TFA-(H2O)4 [F. Ito, Comput. Theor. Chem. 1016 (2013) 48-53.], structure optimization and vibrational calculations were performed for 70 isomeric structures (68 for neutral and 2 for ion-pair...

Infrared spectra of the CH3I–H2O complex and (CH3I)n (n > 2) have been measured with matrix-isolation technique in Ar matrices. Assigned peak positions showed good agreement with the results of quantum chemical calculations. The structure and the characteristic of the intermolecular interaction for each species have been investigated theoretically,...

The infrared spectra of molecular complexes containing chloroform (CHCl(3)) and Lewis bases (N(2), CO, H(2)O, and CH(3)CN) have been observed in an Ar matrix, and vibrational peaks for the 1:1 complexes have been assigned. The C-H stretching band of chloroform in the complexes showed a seamless transition from a blue shift (for N(2) and CO) to a re...

Infrared spectra of CHF2Cl trimer have been assigned in Xe matrix. Twenty-six structural isomers have been obtained by DFT calculations at the B971/6-311++G(3df,3pd) level, and synthetic spectra based on these calculations showed reasonable agreement with the observed spectral pattern.

Malonaldehyde is an open 5-membered ring molecule which exhibits interesting quantum-mechancial effects due to tunnelling of one of its protons. This results in a 21 Cm-1 tunnelling-splitting in the ground vibrational state, which has been well-studied by microwave spectroscopy. We have taken far-infrared Fourier transform spectra of malonaldehyde...

Infrared spectra of trifluoroacetic acid (TFA) hydrates CF3COOH–(H2O)n have been observed in Ar matrix. A comparison of the spectra with theoretical calculations led us to the assignments of vibrational peaks for TFA–(H2O)n up to n = 4. The vibrational peaks of the zwitterion cluster, i.e. (CF3COO−)(H3O+)(H2O)m, have been tentatively assigned for t...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A high-resolution infrared spectrum of ketenimine CH2CNH has been measured in the N–H bending region around 1000cm−1 using an FTIR spectrometer. A rotational analysis of the spectrum revealed perturbations in the vibrational excited state, and they were analyzed in terms of Coriolis coupling and large amplitude motion. The band center of this band...

The supermolecule approach has been used to model molecules embedded in solid argon matrix, wherein interaction between the guest and the host atoms in the first solvation shell is evaluated with the use of density functional calculations. Structural stability and simulated spectra have been obtained for formic acid dimer (FAD)-Ar(n) (n = 21-26) cl...

Hindered torsional motion in a molecule such as HSOH leads to tunnelling splittings. Lying between the simpler limiting cases of strongly hindered torsion (the "we can simply neglect the tunnelling" limit) and that of free internal rotation (the "tunnelling pair of levels are just different vibrational states" limit) HSOH is particularly challengin...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Infrared spectra of CHF2Cl dimer and the CHF2Cl center dot center dot center dot H2O complex have been observed in Xe matrix. A comparison of the spectra with the results of DFT calculations led us to the following conclusion: the structure of CHF2Cl dimer is a head-to-tail type with intermolecular Cl center dot center dot center dot H interaction,...

We have observed infrared spectra of the SO2 clusters in rare gas matrices (Ar, Kr, Xe). The spectral dependence on temperature and concentration led us to the firm assignment of the SO2 dimer in Kr and Xe, the result of which was used to reassign dimeric vibrational transitions in Ar that have been controversial for more than ten years.

Line profiles of a rovibrational transition of 13C acetylene have been measured for various pressures in the near infrared region. In order to accomplish high precision in frequency, we have employed a diode-laser, the frequency of which is locked to an optical comb. By tuning the comb frequency we have achieved a continuous frequency tuning over 2...

We have been developing a spectrometer to record an accurate absorption line profile of a rovibrational transition of acetylene in the 1.54 mum region using an extended cavity laser diode (ECLD) and a mode-locked fiber frequency comb. With the spectrometer, we have recorded the absorption line profiles for various pressures and have observed the co...

Infrared absorption spectra of (HCOOH)(2) and (DCOOH)(2) in solid argon, krypton, and xenon matrices have been measured and each fundamental band has been assigned. Spectra in Ar and Kr matrices showed notable splitting in contrast to those in Xe, which suggests a difference in structure of the trapping sites. A comparison with the reported jet-coo...

A jet-cooled infrared spectrum of the formic acid dimer (HCOOH)2 (FAD) has been measured by cavity ring-down spectroscopy in the C–O stretching region at 8μm. The low rotational temperature in the jet enabled us to observe three vibrational bands which are not resolved at room temperature. The three bands have been interpreted as the Fermi-triad sy...

We have observed infrared spectra of the SO2 clusters in gas phase for the first time by cavity ring-down spectroscopy, and assigned absorption bands of dimer and larger clusters in the OSO asymmetric stretching region. An analysis of the rotational contour showed that the dimeric band can be assigned to the SO2 vibration in an electron-donor side...

We have investigated the phase-sensitive photoionization process of molecules induced by phase-controlled two-color laser pulses consisting of a fundamental light and a second-harmonic light with a pulse duration of 130 fs and an intensity of 1012–1013 W∕cm2. We observed a phase-sensitive forward-backward asymmetry of photofragment emission along t...

The infrared spectra of the (H(2)O)n-SO(2) complexes trapped in argon matrices have been investigated using Fourier transform infrared spectroscopy. In addition to the 1:1 and 2:1 complexes, the first spectroscopic evidence for the 3:1 complex has been obtained from the spectra of the SO stretching and the OH stretching modes. The observed frequenc...

We have observed infrared spectra of the CF(3)I dimer produced in a supersonic jet by matrix-isolation Fourier transform infrared spectroscopy and infrared cavity ring-down (IR-CRD) spectroscopy. In the matrix-isolation experiments, the dimer was isolated in an Ar matrix by the pulse-deposition method. The recorded spectral range covers the symmetr...

The infrared spectrum of dimeric methyl iodide produced in a supersonic jet has been re-measured in the C–H stretching region by cavity ring-down spectroscopy with higher resolution, 0.03 cm−1. Two absorption bands of the dimer, which could not be observed in our previous study [F. Ito, T. Nakanaga, Y. Futami, M. Nakata, Chem. Phys. 286 (2003) 337]...

Infrared spectra of methyl iodide clusters produced in a supersonic jet have been observed in the CH3 bending region at 8 mum by cavity ring-down spectroscopy. The dependence of the spectral features on the mixing ratio of CH3I to He and on the stagnation pressure has allowed us to assign the absorption peaks, with the help of the previous results...

Coherent phase control of the photodissociation reaction of the dimethylsulfide has been achieved by means of quantum-mechanical interference between one- and three-photon transitions. Dimethylsulfide was irradiated by fundamental and frequency-tripled outputs of a visible laser (600.5-602.5 nm), simultaneously to yield CH3S+ and CH3SCH2+ fragment...

The CH3Cl and CH3Br dimers produced by supersonic-jet expansion were directly deposited on a cold plate using a standard matrix-isolation technique. Dependence of the relative intensities of the observed infrared bands on the stagnation pressure was used to assign the dimer bands appearing near the monomer bands. By a comparison of the wavenumber s...

The infrared spectra of the NH2 stretching vibrations of aniline–toluene cluster and corresponding cluster cation have been measured by the infrared depletion method. The NH2 stretching vibrations of aniline–toluene cluster were observed at 3393 and 3468 cm−1. The red shifts from the corresponding bands of aniline monomer are 29 and 40 cm−1, respec...

Coherent phase control of the photoexcitation of CH3I clusters was achieved by means of quantum mechanical interference between 1- and 3-photon transitions. Fundamental and frequency-tripled outputs of a visible laser (600.4–603.4 nm) were used to excite the CH3I clusters, and the resonance enhanced multiphoton ionization spectra with time-of-fligh...

Methyl iodide clusters (CH3I)n in a supersonic jet are photolyzed in an excitation of the valence A band with a tunable ultraviolet light source, and the iodine molecule (I2) thus produced is detected by cavity ring-down (CRD) spectroscopy. A production yield of I2 is measured in the region of 245–275 nm to obtain photofragment excitation (PHOFEX)...

The infrared spectra of the NH stretching vibrations of aniline–(CH3)2O cluster and corresponding cluster cation in 3200–3600cm−1 region have been measured using the infrared depletion method. There are two strong absorption bands at 3383 and 3485cm−1 in the spectrum of aniline–(CH3)2O cluster. The vibrational analysis has shown that one of the NH...

The vibrational spectra of the NH stretching vibrations of aniline–alkene cluster cations have been measured using infrared depletion method. Aniline–ethene cation showed three strong absorption bands at 3448, 3314 and 3220cm−1. The comparison with MO calculation has shown that the main intermolecular interaction is the NH-π type hydrogen bond betw...

Infrared spectra of methyl iodide clusters produced in a supersonic jet have been observed in the C–H stretching region by cavity ring-down spectroscopy. The dependence of the spectra on the mixing ratio of CH3I versus He and on the stagnation pressure has led to a tentative assignment of the absorption peaks to trimer up to pentamer, based on our...

Jet-cooled infrared spectra of the formic acid dimer (HCOOH)2 and its isotopomers (DCOOH)2 and (HCOOD)2 were measured by cavity ring-down spectroscopy in the region of . The `cold band' spectra showed resolved vibrational peaks which are not observed at room temperature while broad structure in the OH stretching region persists, indicating that th...

The infrared spectra of the NH2 stretching vibrations of aniline+–Arn (n=1–21) cluster cations have been measured by the depletion method. Aniline+–Arn clusters were prepared by near-resonant resonance-enhanced multiphoton ionization (REMPI) of larger aniline–Arm clusters. The red shifts of the NH stretching vibrations were 17–25cm−1, depending on...

The NH2 stretching vibrations of the weakly bound clusters of aniline–ethene, aniline–propene and aniline–(1-butene) have been measured by infrared depletion technique. Compared to aniline monomer the frequencies of the NH2 stretching vibrations of the aniline–ethene cluster show small red shifts, suggesting that this cluster is only weakly bound....

The vibrational spectra of aniline(H2O)n+ (n=2–6) in the 3 μm region have been measured. Cluster cations were generated by near resonant two-photon ionization of neutral clusters, and magic numbers were observed at n=4 and 5.The infrared spectra were investigated with the aid of the B3LYP/6-31++G** method. It was found that several isomers coexiste...

The infrared spectrum of aniline–water–pyrrole cluster cation has been measured in the 3 μm region. Four strong vibrational bands were observed at 3313, 3515, 3637, and 3721cm−1, and the cluster dissociated into fragments in two reaction paths, AWP+→AW++P and AWP+→AP++W (A: aniline, W: water, P: pyrrole) when it absorbed an infrared photon. The bra...

The infrared predissociation reaction of the hydrogen bonds of aniline–water–benzene cluster cation (AWB+) in NH and OH stretching region has been investigated. It has been found that an infrared photon can decompose the cluster cation AWB+ into fragments in two different reaction paths; and . The branching ratio of this reaction, R=(AB+/AW+) has b...

CH3I in a supersonic jet was isolated in a low-temperature argon matrix. The observed infrared bands were assigned to monomer and dimers by examining dependence of the intensities on the mixing ratio with argon gas and the stagnation pressure of the supersonic jet. Ab initio calculations at the MP2 level predicted that head-to-tail (HT) and head-to...

Spectroscopic information of ternary aniline clusters which include water has been obtained for the first time by infrared depletion spectroscopy. The vibrational spectra of the NH and OH stretching region of aniline−water−tetrahydrofuran (THF) clusters and their cations were measured by using infrared (IR) depletion spectroscopy. The infrared spec...

The vibrational spectra of aniline-water $_{n} (n=2-6)$ cluster cations in the OH stretching vibration region have been measured by infrared depletion technique. The cluster cations were prepared by the near resonant two-photon ionization of neutral aniline-watern clusters. No structure was observed in the UV-excitation spectra, and the origin of t...

An infrared absorption spectrum of formic acid dimer (HCOOH), in the C-H stretching region has been observed in a supersonic jet by cavity ring-down spectroscopy. In total six vibrational bands have been identified in the region 2800-2950cm(-1), and the center frequency and relative intensity for each of them, as well as its tentative assignment, h...

The vibrational spectra of the NH2 stretching modes of the aniline−furan complex and its cation in a supersonic jet have been measured by infrared depletion spectroscopic methods. Two absorption bands have been observed at 3409 and 3497 cm-1 in the spectrum of the neutral aniline−furan complex, which is red-shifted from the corresponding bands of a...

FTIR absorption spectra of the fundamental bands of LiF and LiCl were measured with an apodized resolution of 0.01 cm-1. The Herman-Wallis analysis of these spectra led to the determination of the ratio of the dipole derivative to the permanent dipole moment, [µe/(dµ/dr)ere], for each molecule. The vibrational dependence of the dipole moment for ea...

The vibrational spectra of the aniline−pyrrole complex and the corresponding complex cation have been measured in the region of the NH stretching vibration using a mass-selective IR−UV double-resonance technique. In the spectrum of the neutral complex, there are three absorption bands at 3393, 3464, and 3496 cm-1, which have been assigned to the sy...

The results of FTIR studies on high-temperature molecules are presented. High-resolution FTIR spectra of diatomic hydrides AlH, GaH and InH were measured and an analysis of intensity distribution in each spectrum led to the determination of the ratio of dipole moment function (DMF) equation presented which were used to estimate the concentration of...

The vibrational spectrum of the aniline-H2O+ cluster cation in the NH and OH stretching vibration region has been measured as depletion of the ion signal induced by the infrared multiphoton decomposition of the cluster cation. Three absorption bands have been observed at 3440, 3636 and 3715 cm−1, which have been assigned to the free NH stretching v...

The vibrational spectra of the NH stretching modes of the aniline dimer cation and the aniline-benzene cluster cation have been measured by infrared depletion spectroscopy, which utilizes infrared multiphoton decomposition of the cluster ions and resonance-enhanced multiphoton ionization-time-of-flight (REMPI-TOF) mass spectrometry. Two strong abso...

The NH2-stretching vibrational modes of four different aniline-X clusters (X = N2, CH4, CHF3, CO) and their corresponding cluster cations were investigated by ion-depletion spectroscopy. The observed frequency shifts of the neutral clusters have been found to be very small, and to be proportional to the red shift of the origin of the S1 ← S0 electr...

The vibrational spectra of aniline-NH3 and aniline-NH3+ clusters in the NH stretching vibration region have been measured using infrared depletion spectroscopic techniques combined with mass spectrometry. There are two strong absorption bands at 3354 and 3479 cm−1 in the spectrum of aniline-NH3. They have been assigned to the stretching vibrations...

The infrared spectra of the NH2 stretching modes of anilinen (n = 1, 2) clusters and corresponding cluster cations in a supersonic jet have been observed using an IR-REMPI double resonance technique. The observed frequencies of the anilineAr cluster are νsym = 3422, and νasym = 3508 cm−, and those of the aniline-Ar+ cation are νsym = 3395 and νasy...

High resolution infrared spectra of the ν5and ν10bands of C2F6in a supersonic jet have been measured using a diode laser spectrometer. The well resolved vibration–rotation lines of these two bands were obtained. The spectra were analyzed using a standard Hamiltonian for a prolate symmetric rotor, and the precise band centers and molecular constants...

An FTIR absorption spectrum of the fundamental band of the AsO radical in its X 2 P r state was measured in the 900–1100 cm 01 region with an apodized resolution of 0.006 cm 01 . About 1000 transitions with £ £ 3, J £ 84.5 were assigned, based on our previous work [K. Essig et al., J. Mol. Spectrosc. 170, 152–157 (1995)], but some discrepancies wer...

Foreign gas effects were measured for the rovibrational lines of NH3 in the upsilon(2) band with O-2, N-2, and air as perturbers, using a high-resolution FTIR spectrometer. The observed line profiles were analyzed by the Voigt-type line profile function, and the Lorentzian broadening coefficients have been determined precisely for 176 lines. The ob...

The reaction F+OCSSF+CO has been investigated by using infrared diode laser spectroscopy to probe both reaction products SF(2Π3/2,1/2) and CO. Fluorine atoms were prepared by pulsed CO2 laser photolysis of SF6 in the presence of OCS. Time-resolved absorption spectra, including many rovibrational lines of SF in the v = 4-3, 3-2, 2-1, and 1-0 bands a...

The infrared spectrum of the AsO radical in its 2Π ground state has been measured using a diode laser spectrometer. Rovibrational transitions of the fundamental and a number of hot bands were measured in both 2Π3/2 and the 2Π1/2 substates to an estimated accuracy of ±0.001 cm−1. These data allowed the accurate determination of a set of molecular pa...

A high-resolution FTIR spectrum of InH produced in a heat pipe cell was observed in absorption; 122 transitions for two isotopic species were measured, and the molecular constants were refined by simultaneous analysis of these transitions with those of the previous measurements (Chem. Phys. Lett.155, 269-272, 1989). Analysis of the Herman-Wallis ef...

The infrared multiphoton decomposition of Si2F6 has been investigated by time-resolved infrared diode laser spectroscopy. Direct formation of SiF2 (X̃1A1) in the ground vibrational state and indirect formation via vibrational relaxation were found. Simultaneous formation of SiF4 with SiF2 was also observed, indicating that a 1,2-fluorine shift occu...

High resolution IR spectra of the overtones and the combination band of the ν4 and ν6 modes of formaldehyde (2ν4, ν4 + ν6 and 2ν6) were measured in the region of 2200–2650 cm−1 using FTIR. The combination band ν4 + ν6, whose dipole transition is forbidden from molecular symmetry, was observed due to the intensity borrowed from the other bands. The...

The high-resolution infrared absorption spectrum of the fundamental band of CF radical has been measured with an FTIR spectrometer. Reliable molecular constants of the vibrationally excited state have been obtained. The vibrational transition dipole moment has been estimated, via Herman-Wallis theory, to be mu10 = -0.14(7) D from the analysis of th...

High-resolution infrared spectra of aluminum hydride and gallium hydride produced in a heat pipe cell by the reaction of corresponding metals with hydrogen at high temperature were successfully observed with an FTIR spectrometer. The 88 and 111 transitions for AIH and GaH were measured and the molecular constants were refined by fitting the newly o...

A simple method for measuring a time-resolved high-resolution FTIR absorption spectrum has been demonstrated using a pulsed electric discharge synchronized to the motion of the moving mirror. This method can be applied to the phenomena which repeat rapidly > ≈ 3 kHz) by using a usual rapid scan FTIR spectrometer without any modification to the soft...

The infrared absorption spectra of the molecular ions H3+ and HN2+ were measured by using the Fourier-transform infrared method and a hollow-cathode discharge cell. From the analysis of the relative intensities and the linewidths of the absorption lines, these ions in the ground vibrational states were found to be well thermalized in the cell. The...

The two reactions F+CH4→CH3+HF (1) and F+CH3I→CH3+IF (2) have been investigated by using time‐resolved diode laser absorption spectroscopy to probe the reaction products CH3 and IF. The fluorine atoms have been generated by the pulsed CO2 laser photolysis of SF6 in the presence of CH4 or CH3I at a total pressure of 5 Pa. Rotational lines of CH3 in...

The high-resolution infrared spectrum of the nu4 band of CH2CNH (ketenimine) has been measured in gas phase using an FTIR spectrometer. Ketenimine was produced by the pyrolysis of butylonitrile and its lifetime was estimated to be a few sec in a glass cell. The spectrum showed complicated features due to vibration-rotation interactions. From an ana...

The high-resolution infrared spectrum of the vq band of CH,CNH (ketenimine) has been measured in gas phase using an FTIR spectrometer. Ketenimine was produced by the pyrolysis of butylonitrile and its lifetime was estimated to be a few set in a glass cell. The spectrum showed complicated features due to vibration-rotation interactions. From an anal...

A novel type of heteropolymolybdate containing Cu(II) was obtained and its crystal structure was determined by X-ray diffraction method. In the structure, two CuO6 octahedra connect two adjacent Mo8O28 units ky corner-sharing to form an infinite chain. The CuO6 prolates along the chain. The axial Cu–O distances and equatrial ones are ca. 2.5 and 2....

The system to observe FTIR spectrum in supersonic free jet expansion was made and the spectra of C2F6 were observed both in a pulsed jet expansion and in a continuous jet expansion. The behavior in the pulsed jet was analyzed from the observed time resolved spectrum. The sharp peaks of v i and v 7 free from the disturbance due to hot bands were fou...