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Toshio Masuda - One of the best experts on this subject based on the ideXlab platform.
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Relationship between the Local Dynamics and Gas Permeability of Para-Substituted Poly(1-Chloro-2-phenylacetylenes)
Macromolecules, 2012Co-Authors: Rintaro Inoue, Toshio Masuda, Toshiji Kanaya, Koji Nishida, Osamu YamamuroAbstract:Local dynamics of para-substituted poly(1-Chloro-2-phenylacetylene) (PCPA) derivatives was studied using quasielastic neutron scattering. Broadening of the dynamic scattering law (S(Q,ω)) was clearly observed for para-substituted PCPA derivatives even in the glassy state, and the observed S(Q,ω) was well fitted to a sum of narrow and broad Lorentzians, which represent the slow and fast motions, respectively. The half-width at half-maximum (Γ) of the narrow Lorentzian exhibited a positive correlation with the CO2 and CH4 permeability coefficients (P), while the Γ from the broad Lorentzian hardly changed despite of the variation of permeability coefficient, indicating that only the narrow component (i.e., the slow motion) contributes to the gas permeability. The Γ from the narrow component was approximately proportional to the diffusion coefficient (D) of the CO2 and CH4 gases, whereas it did not correlate with solubility coefficient (S). This implies that the local mobility affects the gas permeability thr...
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Synthesis and gas permeation properties of para-substituted poly(1-Chloro-2-phenylacetylenes)
Macromolecules, 2006Co-Authors: Yusuke Taniguchi, Toshikazu Sakaguchi, Masashi Shiotsuki, Fumio Sanda, Toshio MasudaAbstract:Para-substituted 1-Chloro-2-phenylacetylenes [ClC≡CC6H4-p-R; R = F (1), Cl (2), Me (3), Br (4), I (5), CF3 (6), SiMe3 (7), SiEt3 (8), Si(n-Pr)3 (9), and Si(i-Pr)3 (10)] were polymerized with a catalyst generated by UV irradiation of Mo(CO)6 in CCl4 to provide the corresponding polymers. The formed polymers except poly(5) were soluble in common organic solvents and afforded free-standing membranes by the casting method except for poly(10) whose molecular weight was rather low. Compared to poly(1-Chloro-2-phenylacetylene) (PCPA), all the polymers in this study exhibited high gas permeability. As the size of para-substituents increased, both the fractional free volume (FFV) and gas permeability increased and then decreased. Consequently, poly(6), which has a relatively bulky CF3 group, showed the largest FFV (0.258) and the highest gas permeability (PO2 = 280 barrers). Poly(9) and poly(10) were more gas-permeable than PCPA despite their small FFV values and showed large diffusion coefficients, which might be...
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LIVING METATHESIS POLYMERIZATION OF 1-Chloro-2-PHENYLACETYLENE BY MoOCI4-BASED CATALYSTS
Journal of Macromolecular Science Part A, 2000Co-Authors: Shigetaka Hayano, Toshio MasudaAbstract:The living polymerization of 1-Chloro-2-phenylacetylene was accomplished by use of the MoOCl4–n–Bu4Sn-EtOH/anisole cata-lyst/solvent system. The polydispersity ratio of the produced poly(1-Chloro-2-phenylacetylene) was as small as 1.1. Living polymerization was verified by the multi-stage polymerization and the monomer-conversion dependence of the molecular weight. Only n-Bu4Sn was effective as cocatalyst of the MoOCl4-based catalyst, and Et3Al, Et2Zn, and n-BuLi were not. Among 1-Chloro-2-phenylacetylene analogues, only para substituted derivatives appeared to polymerize in a living fashion.
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Polymerization of 1‐Chloro‐2‐β‐naphthylacetylene by Mo catalysts and polymer properties
Journal of Polymer Science Part A: Polymer Chemistry, 1996Co-Authors: Kazunari Nanjo, Toshio MasudaAbstract:1-Chloro-2-β-naphthylacetylene (C1βNA) polymerized in good yields in the presence of MoCl 5 -based catalysts. The highest weight-average molecular weight of poly(ClβNA) reached about 3 x 10 5 . The polymer was a yellow solid (absorption cutoff in CHCl 3 450 nm). It was soluble in toluene, Chloroform, etc., and provided a tough film by the solvent casting method. The polymer retained its weight up to 300°C in air ; it was thermally less stable than poly(1-Chloro-2-phenylacetylene) but more stable than poly(β-naphthylacetylene). The oxygen permeability coefficient (Po 2 ) of this polymer was 19 barrers (25°C), which is fairly small for a substituted polyacetylene.
David Lee Phillips - One of the best experts on this subject based on the ideXlab platform.
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Short-time photodissociation dynamics of 1-Chloro-2-iodoethane from resonance Raman spectroscopy
Laser Chemistry, 1999Co-Authors: Xuming Zheng, David Lee PhillipsAbstract:We have obtained A-band absorption resonance Raman spectra of 1-Chloro-2- iodoethane in cyclohexane solution. We have done preliminary time-dependent wavepacket calculations to simulate the resonance Raman intensities and absorption spectrum in order to learn more about the short-time photodissociation dynamics. We compare our preliminary results for 1-Chloro-2-iodoethane with previous resonance Raman results for iodoethane and find that there appears to be more motion along non- C—I stretch modes for 1-Chloro-2-iodoethane than for iodoethane. This is consistent with results of TOF photofragment spectroscopy experiments which indicate much more internal excitation of the photoproducts from 1-Chloro-2-iodoethane photodissociation than the photoproducts from iodoethane photodissociation.
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A-band resonance Raman spectra and short-time photodissociation dynamics of trans 1-Chloro-2-iodoethane in cyclohexane solution
Chemical Physics Letters, 1998Co-Authors: Xuming Zheng, David Lee PhillipsAbstract:Abstract Resonance Raman spectra of 1-Chloro-2-iodoethane in cyclohexane solution are presented for three excitation wavelengths. The fundamentals, overtones and combination bands of the nominal CCCl bend ( ν 10 ), the nominal C–I stretch ( ν 9 ), and the C–Cl stretch ( ν 8 ) vibrational modes can account for most of the resonance Raman intensity. The resonance Raman spectra and associated short-time photodissociation dynamics of 1-Chloro-2-iodoethane are compared with iodoethane and this suggests that the Chloroethyl radical receives more internal excitation than the ethyl radical from the A-band photodissociation in as much as the initial dynamics determines the internal excitation of the alkyl radical photoproducts.
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A-band resonance Raman spectra and short-time photodissociation dynamics of trans 1-Chloro-2-iodoethane in cyclohexane solution
Chemical Physics Letters, 1998Co-Authors: Xuming Zheng, David Lee PhillipsAbstract:Resonance Raman spectra of 1-Chloro-2-iodoethane in cyclohexane solution are presented for three excitation wavelengths. The fundamentals, overtones and combination bands of the nominal CCCl bend (ν 10), the nominal C-I stretch (ν 9), and the C-Cl stretch (ν 8) vibrational modes can account for most of the resonance Raman intensity. The resonance Raman spectra and associated short-time photodissociation dynamics of 1-Chloro-2-iodoethane are compared with iodoethane and this suggests that the Chloroethyl radical receives more internal excitation than the ethyl radical from the A-band photodissociation in as much as the initial dynamics determines the internal excitation of the alkyl radical photoproducts.link_to_subscribed_fulltex
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Vibrational spectra and assignments of 1-Chloro-2-iodoethane
Vibrational Spectroscopy, 1998Co-Authors: Xuming Zheng, David Lee PhillipsAbstract:Raman and infrared absorption spectra of liquid 1-Chloro-2-iodoethane have been obtained. Additional Raman spectra of 1-Chloro-2-iodoethane in room temperature solutions with different solvents and at low temperature (77 K) in the solid state have also been obtained in order to help elucidate which vibrational modes belong to the gauche and anti conformers. Ab initio vibrational frequencies of the gauche and anti conformers have been calculated at the RHF/3-21G* level of theory by using the point group symmetries of C 1 and C s, respectively. Vibrational frequency assignments for all eighteen infrared and Raman active modes have been made for both the gauche and anti conformers. © 1998 Elsevier Science B.V. All rights reserved.link_to_subscribed_fulltex
Alberto Gambi - One of the best experts on this subject based on the ideXlab platform.
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rotational spectra of 1 Chloro 2 fluoroethylene i main isotopologues and deuterated species of the trans isomer
Journal of Chemical Physics, 2006Co-Authors: Gabriele Cazzoli, Alberto Gambi, Cristina Puzzarini, Jurgen GaussAbstract:Guided by theoretical predictions, the rotational spectra of the mono- and bideuterated species of trans-1-Chloro-2-fluoroethylene, CHCl35CDF, CHCl37CDF, CDCl35CHF, CDCl37CHF, CDCl35CDF, and CDCl37CDF, have been recorded for the first time. Assignment of the ΔJ=0 and ΔK−1=+1 bands with K−1=3,4,5,… (all isotopic species) as well as of several ΔJ=±1 and ΔK−1=+1 transitions (all isotopic species except CHCl37CDF, CDCl37CHF, and CDCl37CDF) led to the accurate determination of the ground-state rotational constants, the quartic, and some sextic centrifugal distortion constants, as well as the nuclear quadrupole coupling constants for both Cl35 and Cl37 in good agreement with corresponding theoretical predictions based on high-level coupled-cluster calculations. Inconsistencies of the present spectroscopic parameters with respect to those reported earlier for the two main isotopologues, i.e., CHCl35CHF and CHCl37CHF, necessitated a reinvestigation of the rotational spectra for these two isotopic speci...
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rotational spectra of 1 Chloro 2 fluoroethylene ii equilibrium structures of the cis and trans isomer
Journal of Chemical Physics, 2006Co-Authors: Cristina Puzzarini, Alberto Gambi, Gabriele Cazzoli, Jurgen GaussAbstract:Equilibrium structures for the cis and trans isomer of 1-Chloro-2-fluoroethylene are reported. The structures are obtained within a least-squares fit procedure using the available experimental ground-state rotational constants for various isotopic species of both forms. Vibrational effects were eliminated before the analysis using vibration-rotation interaction constants derived from computed quadratic and cubic force fields with the required quantum chemical calculations carried out using second-order Moller-Plesset perturbation as well as coupled-cluster (CC) theory. The semiexperimental or empirical equilibrium geometries obtained in this way agree well with the corresponding theoretical predictions obtained from CC calculations [at the CCSD(T) level] after extrapolation to the complete basis-set limit and inclusion of core-valence correlation corrections. The present results allow a detailed analysis of the geometrical differences between the two forms of 1-Chloro-2-fluoroethylene. They are also compa...
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An ab initio study of trans-1-Chloro-2-fluoroethylene: Equilibrium structure and molecular properties
The Journal of Chemical Physics, 2003Co-Authors: Cristina Puzzarini, Gabriele Cazzoli, Alberto GambiAbstract:The equilibrium structure and molecular properties of trans-1-Chloro-2-fluoroethylene have been investigated theoretically at high level of theory. Very accurate results are presented. As far as the equilibrium structure is concerned, coupled-cluster approach with perturbative inclusion of triples and basis sets of triple and quadruple zeta quality have been employed. Core correlation effects and basis set limit extrapolation have been taken into account in order to obtain best estimates of equilibrium geometry. The molecular dipole moment has been calculated at coupled-cluster level using bases of different quality including diffuse functions and performing the extrapolation to the infinite basis set limit. In addition, the complete inertial nuclear quadrupole tensor, evaluated from the electric field gradient at the chlorine nucleus, has been computed at different level of theory: The multiconfiguration self-consistent field, the Moller–Plesset many-body perturbation to second order and the coupled-clus...
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The anharmonic force field of cis-1-Chloro-2-fluoroethylene
Molecular Physics, 2002Co-Authors: Alberto Gambi, Cristina Puzzarini, Gabriele Cazzoli, Luca Dore, Paolo PalmieriAbstract:A comprehensive anharmonic vibrational analysis of cis-1-Chloro-2-fluoroethylene and its isotopomers has been performed on the basis of a complete ab initio quartic force field constructed by means of second-order M⊘ller-Plesset perturbation theory (MP2) and the coupled-cluster singles and doubles approach, augmented for structural optimization and harmonic force field by a contribution of connected triple excitations (CCSD(T)). The theoretical force field was scaled by global least-squares fitting to all spectroscopic data and parameters experimentally determined for this molecule. This final force field, employing standard perturbation theory, yields a complete set of spectroscopic molecular constants providing a critical assessment of experimental rotational and centrifugal distortion constants, fundamentals, overtones, and combination bands determined over many years. Effects of Fermi and Darling-Dennison resonances were included by matrix diagonalization.
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Molecular structure of cis-1-Chloro-2-fluoroethylene from ab initio calculations and microwave spectroscopy
Physical Chemistry Chemical Physics, 2001Co-Authors: Cristina Puzzarini, Gabriele Cazzoli, Luca Dore, Alberto GambiAbstract:The molecular structure of cis-1-Chloro-2-fluoroethylene has been investigated both theoretically and experimentally. As far as ab initio computations are concerned, the equilibrium geometry has been evaluated using the coupled-cluster approach [CCSD(T)] and basis sets of triple and quadruple zeta quality. Accurate results are presented. A recommended equilibrium geometry, obtained by adding ad hoc corrections, is also given. The centimetre and millimetre-wave spectra of the following 8 isotopomers have been observed: CD35ClCHF, CD37ClCHF, CH35ClCDF, CH37ClCDF, CD35ClCDF, CD37ClCDF, 13CH35ClCHF, CH35Cl13CHF. Ground state rotational and quartic centrifugal distortion constants and diagonal elements of the nuclear quadrupole tensor (for both 35Cl and 37Cl) have been accurately determined. The structure of cis-1-Chloro-2-fluoroethylene has been experimentally determined for the first time by isotopic substitution, employing three independent methods. A comparison between the experimental and theoretical geometry is also presented.
Cristina Puzzarini - One of the best experts on this subject based on the ideXlab platform.
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rotational spectra of 1 Chloro 2 fluoroethylene i main isotopologues and deuterated species of the trans isomer
Journal of Chemical Physics, 2006Co-Authors: Gabriele Cazzoli, Alberto Gambi, Cristina Puzzarini, Jurgen GaussAbstract:Guided by theoretical predictions, the rotational spectra of the mono- and bideuterated species of trans-1-Chloro-2-fluoroethylene, CHCl35CDF, CHCl37CDF, CDCl35CHF, CDCl37CHF, CDCl35CDF, and CDCl37CDF, have been recorded for the first time. Assignment of the ΔJ=0 and ΔK−1=+1 bands with K−1=3,4,5,… (all isotopic species) as well as of several ΔJ=±1 and ΔK−1=+1 transitions (all isotopic species except CHCl37CDF, CDCl37CHF, and CDCl37CDF) led to the accurate determination of the ground-state rotational constants, the quartic, and some sextic centrifugal distortion constants, as well as the nuclear quadrupole coupling constants for both Cl35 and Cl37 in good agreement with corresponding theoretical predictions based on high-level coupled-cluster calculations. Inconsistencies of the present spectroscopic parameters with respect to those reported earlier for the two main isotopologues, i.e., CHCl35CHF and CHCl37CHF, necessitated a reinvestigation of the rotational spectra for these two isotopic speci...
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rotational spectra of 1 Chloro 2 fluoroethylene ii equilibrium structures of the cis and trans isomer
Journal of Chemical Physics, 2006Co-Authors: Cristina Puzzarini, Alberto Gambi, Gabriele Cazzoli, Jurgen GaussAbstract:Equilibrium structures for the cis and trans isomer of 1-Chloro-2-fluoroethylene are reported. The structures are obtained within a least-squares fit procedure using the available experimental ground-state rotational constants for various isotopic species of both forms. Vibrational effects were eliminated before the analysis using vibration-rotation interaction constants derived from computed quadratic and cubic force fields with the required quantum chemical calculations carried out using second-order Moller-Plesset perturbation as well as coupled-cluster (CC) theory. The semiexperimental or empirical equilibrium geometries obtained in this way agree well with the corresponding theoretical predictions obtained from CC calculations [at the CCSD(T) level] after extrapolation to the complete basis-set limit and inclusion of core-valence correlation corrections. The present results allow a detailed analysis of the geometrical differences between the two forms of 1-Chloro-2-fluoroethylene. They are also compa...
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An ab initio study of trans-1-Chloro-2-fluoroethylene: Equilibrium structure and molecular properties
The Journal of Chemical Physics, 2003Co-Authors: Cristina Puzzarini, Gabriele Cazzoli, Alberto GambiAbstract:The equilibrium structure and molecular properties of trans-1-Chloro-2-fluoroethylene have been investigated theoretically at high level of theory. Very accurate results are presented. As far as the equilibrium structure is concerned, coupled-cluster approach with perturbative inclusion of triples and basis sets of triple and quadruple zeta quality have been employed. Core correlation effects and basis set limit extrapolation have been taken into account in order to obtain best estimates of equilibrium geometry. The molecular dipole moment has been calculated at coupled-cluster level using bases of different quality including diffuse functions and performing the extrapolation to the infinite basis set limit. In addition, the complete inertial nuclear quadrupole tensor, evaluated from the electric field gradient at the chlorine nucleus, has been computed at different level of theory: The multiconfiguration self-consistent field, the Moller–Plesset many-body perturbation to second order and the coupled-clus...
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The anharmonic force field of cis-1-Chloro-2-fluoroethylene
Molecular Physics, 2002Co-Authors: Alberto Gambi, Cristina Puzzarini, Gabriele Cazzoli, Luca Dore, Paolo PalmieriAbstract:A comprehensive anharmonic vibrational analysis of cis-1-Chloro-2-fluoroethylene and its isotopomers has been performed on the basis of a complete ab initio quartic force field constructed by means of second-order M⊘ller-Plesset perturbation theory (MP2) and the coupled-cluster singles and doubles approach, augmented for structural optimization and harmonic force field by a contribution of connected triple excitations (CCSD(T)). The theoretical force field was scaled by global least-squares fitting to all spectroscopic data and parameters experimentally determined for this molecule. This final force field, employing standard perturbation theory, yields a complete set of spectroscopic molecular constants providing a critical assessment of experimental rotational and centrifugal distortion constants, fundamentals, overtones, and combination bands determined over many years. Effects of Fermi and Darling-Dennison resonances were included by matrix diagonalization.
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Molecular structure of cis-1-Chloro-2-fluoroethylene from ab initio calculations and microwave spectroscopy
Physical Chemistry Chemical Physics, 2001Co-Authors: Cristina Puzzarini, Gabriele Cazzoli, Luca Dore, Alberto GambiAbstract:The molecular structure of cis-1-Chloro-2-fluoroethylene has been investigated both theoretically and experimentally. As far as ab initio computations are concerned, the equilibrium geometry has been evaluated using the coupled-cluster approach [CCSD(T)] and basis sets of triple and quadruple zeta quality. Accurate results are presented. A recommended equilibrium geometry, obtained by adding ad hoc corrections, is also given. The centimetre and millimetre-wave spectra of the following 8 isotopomers have been observed: CD35ClCHF, CD37ClCHF, CH35ClCDF, CH37ClCDF, CD35ClCDF, CD37ClCDF, 13CH35ClCHF, CH35Cl13CHF. Ground state rotational and quartic centrifugal distortion constants and diagonal elements of the nuclear quadrupole tensor (for both 35Cl and 37Cl) have been accurately determined. The structure of cis-1-Chloro-2-fluoroethylene has been experimentally determined for the first time by isotopic substitution, employing three independent methods. A comparison between the experimental and theoretical geometry is also presented.
Jurgen Gauss - One of the best experts on this subject based on the ideXlab platform.
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rotational spectra of 1 Chloro 2 fluoroethylene i main isotopologues and deuterated species of the trans isomer
Journal of Chemical Physics, 2006Co-Authors: Gabriele Cazzoli, Alberto Gambi, Cristina Puzzarini, Jurgen GaussAbstract:Guided by theoretical predictions, the rotational spectra of the mono- and bideuterated species of trans-1-Chloro-2-fluoroethylene, CHCl35CDF, CHCl37CDF, CDCl35CHF, CDCl37CHF, CDCl35CDF, and CDCl37CDF, have been recorded for the first time. Assignment of the ΔJ=0 and ΔK−1=+1 bands with K−1=3,4,5,… (all isotopic species) as well as of several ΔJ=±1 and ΔK−1=+1 transitions (all isotopic species except CHCl37CDF, CDCl37CHF, and CDCl37CDF) led to the accurate determination of the ground-state rotational constants, the quartic, and some sextic centrifugal distortion constants, as well as the nuclear quadrupole coupling constants for both Cl35 and Cl37 in good agreement with corresponding theoretical predictions based on high-level coupled-cluster calculations. Inconsistencies of the present spectroscopic parameters with respect to those reported earlier for the two main isotopologues, i.e., CHCl35CHF and CHCl37CHF, necessitated a reinvestigation of the rotational spectra for these two isotopic speci...
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rotational spectra of 1 Chloro 2 fluoroethylene ii equilibrium structures of the cis and trans isomer
Journal of Chemical Physics, 2006Co-Authors: Cristina Puzzarini, Alberto Gambi, Gabriele Cazzoli, Jurgen GaussAbstract:Equilibrium structures for the cis and trans isomer of 1-Chloro-2-fluoroethylene are reported. The structures are obtained within a least-squares fit procedure using the available experimental ground-state rotational constants for various isotopic species of both forms. Vibrational effects were eliminated before the analysis using vibration-rotation interaction constants derived from computed quadratic and cubic force fields with the required quantum chemical calculations carried out using second-order Moller-Plesset perturbation as well as coupled-cluster (CC) theory. The semiexperimental or empirical equilibrium geometries obtained in this way agree well with the corresponding theoretical predictions obtained from CC calculations [at the CCSD(T) level] after extrapolation to the complete basis-set limit and inclusion of core-valence correlation corrections. The present results allow a detailed analysis of the geometrical differences between the two forms of 1-Chloro-2-fluoroethylene. They are also compa...
