Resonance enhanced multiphoton ionization spectroscopy of carbon disulphide

The vacuum UV photoabsorption spectrum of CH 3 Cl has been recorded between 6 and 25 eV. A large number of vibronic bands are observed. These were partly ascribed to vibrationless Rydberg transitions. In the high photon energy range of 12-25 eV, very weak diffuse bands are mostly assigned to transitions from the 3a 1 , 1e and 2a 1 to 3s orbitals. In the 6-12 eV photon energy range, numerous weak to strong bands are observed. The sharpness is very variable over the entire spectral region. In a first step, the interpretation of the spectrum and the assignment of the Rydberg transitions is based on the simple Rydberg formula. The observed features are classified in two groups of four series, each converging to one of the two spin-orbit components of the X 2 E state of CH 3 Cl + . Rydberg series of nsa 1 (δ = 1.069 and 1.064), npa 1 (δ = 0.68 and 0.66), npe (δ = 0.438 and 0.427) and nd (δ = -0.040 and -0.092) characters are observed. The same measurements have been made for the first time on CD 3 C1 in the 6-12 eV photon energy range. The same Rydberg transitions are observed. Analogous series are characterized by about the same δ values: nsa 1 (δ = 1.038 and 0.968), npa 1 (δ = 0.65 and 0.61), npe (δ = 0.458 and 0.462) and nd (δ = -0.004 and -0.082). Ionization energies for CD 3 Cl X 2 E 3/2 at 11.320 eV and X 2 E 1/2 at 11.346 eV are deduced. In a second step, we fitted the experimental data for the nsa 1 and npa 1 states to an energy expression taking into account both the exchange interaction and the spin-orbit coupling. This accounts for the progressive switching from Hund's case (a) to Hund's case (c).

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“…It seems therefore more reasonable to assign the largest quantum defect to the npa 1 series [28][29][30].…”

Section: The Low Energy Region: Analysis Using the Rydberg Formula [1]mentioning

confidence: 99%

The vacuum UV photoabsorption spectrum of methyl chloride (CH3Cl) and its perdeuterated isotopomer CD3Cl I. A Rydberg series analysis

et al. 2001

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“…15 The deflected and subsequently ionized molecules fly into a 570 mm TOF tube along the molecular beam axis ͑z axis͒ guided by an electrostatic lens system of three electrode plates: a repeller, an extractor, and a ground ͑Fig. 1͒.…”

Section: Methodsmentioning

confidence: 99%

“…The photoelectron energies of benzene and CS 2 are 1.15 eV and 0.18 eV, which give transverse velocities of 4.5 m/s and 1.8 m/s, respectively. 14,15 Benzene undergoes a vibrational relaxation 14 with a rate 19 of 10 14 s Ϫ1 after reaching high vibrational levels of the 1 E 1u electronic state by absorbing the third photon with a wavelength of 477.4 nm. The ionization rate from the 1 E 1u state is estimated to be 10 12 s Ϫ1 for a dye laser intensity of 2ϫ10 10 W/cm 2 .…”

Section: A Deflection Of Moleculesmentioning

confidence: 99%

Molecular lens applied to benzene and carbon disulfide molecular beams

Chung

Zhao

Lee

et al. 2001

The Journal of Chemical Physics

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A molecular lens of the nonresonant dipole force formed by focusing a nanosecond IR laser pulse has been applied to benzene and CS 2 molecular beams. Using the velocity map imaging technique for molecular ray tracing, characteristic molecular lens parameters including the focal length ͑f ͒, minimum beam width ͑W͒, and distance to the minimum beam width position ͑D͒ were determined. The laser intensity dependence of the observed lens parameters was in good agreement with theoretical predictions. W was independent of the laser peak intensity (I 0 ), whereas f and D varied linearly with 1/I 0 . The differences in lens parameters between the molecular species were well correlated with the polarizability per mass values of the molecules. A high chromatographic resolution of Rsϭ0.84 was achieved between the images of benzene molecular beams undeflected and deflected by the lens. The possibilities for a new type of chromatography are discussed.

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“…Thus, a one-photon 267-nm excitation process will not occur. According to the (2+1) REMPI experimental study by Morgan et al [15], [21].…”

Section: S T S T S T T T C T T Erf T T C T T Erf Tmentioning

confidence: 99%

“…These include high-resolution absorption [11], resonance enhanced multiphoton ionization (REMPI) [12] and laser induced fluorescence [13] spectroscopic studies, and dynamic studies [14], to determine the channel branch ratio, the fragment energy partition, and the lifetime. Rydberg series were investigated in a wide range of excitation energies using the (2+1) and (3+1) REMPI methods [15]. In addition to the neutral CS 2 molecule, the structure and dynamics of the ground and excited ionic state, CS 2 + , have been investigated by several groups, using synchrotron-based pulse-field-ionization photoelectron spectroscopy [16], the photoelectron photoion coincidence technique [17], photofragment excitation spectroscopy [18][19][20], and the optical-optical double resonance technique [21].…”

mentioning

confidence: 99%

Ultrafast dynamics and dissociative ionization of CS2 molecules studied via the femtosecond pump-probe method

et al. 2011

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The ultrafast dynamics and dissociative ionization of CS 2 were studied using the pump-probe method with time-of-flight mass spectroscopy. The transient behavior of both parent ion (CS 2 + ) and fragment ions (S + and CS + ) was observed. It was found that all the ionic signals decay exponentially with lifetimes that were different for delay times, t>0 and t<0, which can be attributed to the evolution of different Rydberg states pumped by 267-nm and 400-nm laser pulses. The lifetimes of two Rydberg states were obtained simultaneously from one fitting of the transients. The fragment ions were produced by the dissociation of CS 2 + , and it is suggested that the final ionic state is the C Photo-induced dynamics of polyatomic molecules has been of area of research of great interest for many years. With the advent of the ultrafast laser technology and the pump-probe method, one can "see" the making and breaking of the molecular bonds, and can follow the flow of energy and charge within molecular systems in real time. Carbon disulfide (CS 2 ) is a prototypical triatomic molecule, which plays an important role in stratospheric chemistry. CS 2 has been the subject of high-resolution spectroscopic measurements and photodissociation dynamics studies for *Corresponding author (email: xuhf@jlu.edu.cn) many years. Rich information on the first five electronic excited states of neutral CS 2 in the wavelength range of 290-410 nm has been obtained [10]. Efforts have also been made to understand the structure and non-adiabatic dynamics of the predissociation 1 B 2 ( 1 Σ u + ) state over the wavelength range 180-230 nm. These include high-resolution absorption [11], resonance enhanced multiphoton ionization (REMPI) [12] and laser induced fluorescence [13] spectroscopic studies, and dynamic studies [14], to determine the channel branch ratio, the fragment energy partition, and the lifetime. Rydberg series were investigated in a wide range of excitation energies using the (2+1) and (3+1) REMPI methods [15]. In addition to the neutral CS 2 molecule, the structure and dynamics of the ground and excited ionic state, CS 2 + , have been investigated by several groups, using synchrotron-based pulse-field-ionization photoelectron spectroscopy [16], the photoelectron photoion coincidence technique [17], photofragment excitation spectroscopy [18][19][20], and the optical-optical double resonance technique

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Resonance enhanced multiphoton ionization spectroscopy of carbon disulphide

Cited by 49 publications

References 58 publications

The vacuum UV photoabsorption spectrum of methyl chloride (CH3Cl) and its perdeuterated isotopomer CD3Cl I. A Rydberg series analysis

The vacuum UV photoabsorption spectrum of methyl chloride (CH3Cl) and its perdeuterated isotopomer CD3Cl I. A Rydberg series analysis

Molecular lens applied to benzene and carbon disulfide molecular beams

Ultrafast dynamics and dissociative ionization of CS2 molecules studied via the femtosecond pump-probe method

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