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1.
An emission system of I2 in Ar in the region 2830–2890 Å is examined under high resolution and found to display fine violet-degraded band structure. This system is interpreted as a charge-transfer transition originating from an ion-pair state near 47 000 cm?1 and terminating on a weakly bound state which dissociates to two ground-state atoms. This interpretation is supported by spectral simulations employing a bound-free model. The transition is tentatively assigned as , according to which the excited state becomes the fourth ion-pair state near 47 000 cm?1 to be experimentally characterized, and the lower state is the last component of the lowest 3Π state to be identified. The vibrational assignments include about 45 bands in 127I2 and 129I2, spanning v′ = 0–4 and v″ = 6–19, but with the numbering of the lower state remaining uncertain by several units. The main spectroscopic constants for the excited state are Te = 47 070 cm?1, ?e = 105.7 cm?1, ?exe = 0.49 cm?1. The spectral simulations place the lower state's potential curve 34 650 cm?1 below the upper state at R = R′e, with slope ?850 cm?1/Å. For our “best” numbering of the lower state, ?e = 20.5 cm?1, ?exe = 0.29 cm?1, Te = 12 190 cm?1, and De = 360 cm?1. 相似文献
2.
The rotational structure of the 2B1 (K′ = 0) subbands of NO2 with v′2 = 6, 7, 8, and 9 were analyzed by means of the time-gated excitation spectrum. The excitation spectrum monitored at ν2, 2ν2, or 3ν2 fluorescence band was fairly simplified in comparison to its corresponding absorption spectrum. The band origins and rotational constants are evaluated from the observed data: ν0 = 20205.0 cm?1, for v′2 = 6; ν0 = 21104.4 cm?1, for v′2 = 7; ν0 = 22001.9 cm?1, for v′2 = 8ν0 = 22898.0 cm?1, for v′2 = 9. The value of extrapolated to v′ = 0 is 0.370 cm?1. This value corresponds to the bond length of 1.19 Å. Fluorescence decays of these excited levels were also studied. Radiative lifetimes obtained by extrapolation to zero pressure from the plots were 25–40 μsec. The short-lived excited levels previously reported by some authors were not found. 相似文献
3.
Single srystals of calcium tartrate doped with VO2+ are grown from silica gel. Its optical absorption spectrum is studied at laboratory and liquid air temperatures. The spectrum is analysed and ascribed to VO2+ ion in C4v symmetry. The following crystal field parameters are evaluated. 相似文献
4.
J.C.D. Brand U.D. Deshpande A.R. Hoy S.M. Jaywant 《Journal of Molecular Spectroscopy》1983,100(1):143-150
The E-B (0g+-0u+) band system of Br2 has been investigated at Doppler-limited resolution using polarization labeling spectroscopy. Merged E state data for the three naturally occurring isotopes in the range vE = 0–16, expressed in terms of the constants for 79Br2, are (in cm?1) Y0,0 = 49 777.962(54), Y1,0 = 150.834(22), Y2,0 = ?0.4182(28), Y3,0 = 6.6(11) × 10?4, Y0,1 = 4.1876(28) × 10?2, Y1,1 = ?1.607(16) × 10?4, and Y0,2 = 1.39(39) × 10?8. The bond distance is , and the diabatic dissociation energy to . 相似文献
5.
A weak emission spectrum of I2 near 2770 Å is reanalyzed and found to to minate on the A(1u3Π) state. The assigned bands span v″ levels 5–19 and v′ levels 0–8. The new assignment is corroborated by isotope shifts, band profile simulations, and Franck-Condon calculations. The excited state is an ion-pair state, probably the 1g state which tends toward . In combination with other results for the A state, the analysis yields the following spectroscopic constants: T″e = 10 907 cm?1, ″e = 1640 cm?1, ω″e = 95 cm?1, ; T′e = 47 559.1 cm?1, ω′e = 106.60 cm?1, . 相似文献
6.
Molecular beam electric resonance spectroscopy has been used to measure the l-type doubling transitions in carbonyl sulfide. Transitions in J = 4 to J = 20 have been observed for the (0220) vibrational state and for J = 1 and J = 2 for the (0310) state. The data has been analyzed to give the v = 2 energy separation , and the vibrational dependence of q to be 86.52(9)(v2 + 1) KHz. The dipole moment of the (0220) vibrational state is 0.6936(3) D. 相似文献
7.
Peter J Domaille Timothy C Steimle David O Harris 《Journal of Molecular Spectroscopy》1977,68(1):146-155
The pure rotational spectrum of the state of the gaseous SrF radical has been measured using microwave optical double resonance (MODR) techniques. The analysis fully confirms the recent dye laser excitation spectrum and rotational assignment of the system. Transitions were measured in both the v″ = 0 and v″ = 1 states to give values of Be″ = 0.250533 cm?1, αe″ = 1.546 × 10?3 cm?1 and γ″ (spin-rotation) = 2.49 × 10?3 cm?1. General qualitative features of MODR in 2Σ+ states are treated and suggested improvements for obtaining experimental hyperfine constants are discussed. The more precise ground state constants are merged with the B-X optical analysis to obtain a more accurate set of constants for both states. 相似文献
8.
The Raman active fundamentals ν1(A1g), ν2(Eg), ν5(F2g), and the overtone 2ν6 of SF6 have been investigated with a higher resolution and the band origins were estimated to be: ν1 = 774.53 cm?1, ν2 = 643.35 cm?1, ν5 = 523.5 cm?1, and 2ν6 = 693.8 cm?1. Raman and infrared data have been combined for estimation of several anharmonicity constants. The ν6 fundamental frequency is calculated as 347.0 cm?1. From the analysis of the ν2 Raman band, the following rotational constants of both the ground and upper states have been calculated: ; . 相似文献
9.
The vibration-rotation transitions for v = 1 ← 0 of NO () have been studied by using the technique of laser magnetic resonance spectroscopy. Five magnetic resonance lines are observed with three CO laser lines in the range from 1859 to 1886 cm?1. From these, three zero-field transition frequencies, v = 1 ← 0; , , and are obtained with an accuracy of ±0.0007 cm?1. The molecular constants which have been determined by borrowing centrifugal constants from a previous infrared work are , , and . 相似文献
10.
Kentarou Kawaguchi Chikashi Yamada Yoshiaki Hamada Eizi Hirota 《Journal of Molecular Spectroscopy》1981,86(1):136-142
The fundamental bands of the CF radical in the and electronic states were observed by using an infrared tunable diode laser as a source. Zeeman modulation could be used in detecting lines not only in the state, but also in , because the CF radical deviates considerably from Hund's case (a). From the least-squares analysis of the observed spectra, the following molecular constants were obtained: Be = 1.416 704 (37) cm?1, αe = 0.018 419 (50) cm?1, , De = 6.68 (15) × 10?6cm?1, p0 = 0.008 580 (21) cm?1, p1 = 0.008 52 (11) cm?1, and , with three standard errors in parentheses. 相似文献
11.
Clive E. Barnes John M. Brown Alan D. Fackerell Trevor J. Sears 《Journal of Molecular Spectroscopy》1982,92(2):485-496
Lines in the ν3 (“antisymmetric” stretch) fundamental of the NCO radical in the state were studied by CO laser magnetic resonance. The observations were assigned to P and R lines in the vibration-rotation band and lead to a precise determination of the vibrational interval and the anharmonic correction to the rotational constant: ν3 = 1920.60645(19) cm?1, α3 = 0.003338(21) cm?1. A single transition in the hot band (011)-(010), was detected. This observation is used to determine the origin of the hot band as 1907.11892(20) cm?1, i.e., the anharmonicity parameter x23 = ?13.48753(28) cm?1. 相似文献
12.
Takehiko Tanaka Robert W. Field David O. Harris 《Journal of Molecular Spectroscopy》1975,56(2):188-199
A rotational assignment of approximately 80 lines with Ka′ = 0, 1, 2, 3, and 4 has been made of the 593 nm band of NO2 using cw dye laser excitation and microwave optical double-resonance spectroscopy. Rotational constants for the 2B2 state were obtained as A = 8.52 cm?1, B = 0.458 cm?1, and C = 0.388 cm?1. Spin splittings for the Ka′ = 0 excited state levels fit a simple symmetric top formula and give . Spin splittings for Ka′ = 1 (N′ even) are irregular and are shown to change sign between N′ = 6 and 8. Assuming that the large inertial defect of 4.66 amu Å2 arises solely from A, a structure for the 2B2 state is obtained which gives and an ONO angle of 105°. Alternatively, weighting the three rotational constants equally gives and θ = 118°. 相似文献
13.
The excitation spectrum of NO2 was investigated in the blue region by using a Nd:YAG laser-pumped dye laser. The 463- and 474-nm bands of the 2B2-2A1 system were identified and analyzed using the simplification that occurs if the excitation spectrum is monitored at particular wavelengths. Band origins and rotational constants were obtained. Vibrational assignments have been given to these bands by comparing the Franck-Condon Factors calculated for the 2B2-2A1 system with the fluorescence intensities of bands going to different vibrational levels of the ground state. The vibrational assignments and molecular constants obtained in this work are (v′1, v′2, v′3) = (3, 11, 0)ν0(K′ = 0) = 21584.1, , and for the 463-nm band; and (v′1, v′2, v′3) = (2, 12, 0), ν0(K′ = 1) = 21104.9, , and for the 474-nm band. 相似文献
14.
The phase analysis was carried out for the system (l?x) CrSi2 + xMnSi2 in the range 0?x?0.5 by X-ray technique. The solid solution Cr1?xMnxSi2 was identified in the composition range 0?x?0.225, where the added Mn-atoms occupied substitutionally the Cr-atom sites in the CrSi2 structure. Resistivity, Hall coefficient as well as thermoelectric power were measured as functions of temperature in the range, 80–1200 K and composition x in the single phase region, 0 ?x?0.225. The pure CrSi2 (x = 0) was a p-type degenerate semiconductor, whose hole concentration was determined to be 7.7 × 1020 cm?3 at room temperature. Mn-atoms introduced in the CrSi2 crystal were found to act as donors. The forbidden energy gap was determined to be 0.30 eV from the Hall-data in the intrinsic region. With increasing x, a conversion from p- into n-type semiconductor took place in Cr1?xMnxSiy. From the analysis of Hall- as well as resistivity-data, the mobility ratio b was obtained as a function of composition x. It was revealed that b increased with increasing x from 0.01 for x = 0 to 0.12 for x = 0.182. The electron-hole concentration product could be expressed as , and the hole mobility as in the acoustic scattering region. The effective mass of hole was found out to be 3.2 m0 and independent of x, whereas that of electron varied from 20.2 m0 for x = 0 to 7.5 m0 for x = 0.182. When these parameters are used, the theoretical temperature variation of the thermoelectric power curve was found out to be in good agreement with the measurement. 相似文献
15.
H.D. Bist J.C.D. Brand A.R. Hoy V.T. Jones R.J. Pirkle 《Journal of Molecular Spectroscopy》1977,66(3):411-420
The band system of NO2, , has been measured in absorption in a neon matrix at 6 K, using 15NO2 and N18O2 in addition to the normal isotope. The spectrum consists essentially of a single, long progression of bands terminating on successive levels of the bending mode in the upper state. Transitions to odd- and even-v2′ states occur with a uniform intensity distribution indicating that the rotation of the bent ground state of NO2 about its near-prolate axis is hindered in the matrix. The observations strongly suggest that the top axis of the molecule coincides with a C2 axis of neon crystals in the polycrystalline matrix. Relative to the vapor absorption the matrix spectrum is red shifted by about 150 cm?1, the crystal field parameter V2 and principal constants of the state of 14N16O2 in neon being 相似文献
16.
L Nemes 《Journal of Molecular Spectroscopy》1978,72(1):102-123
Medium resolution infrared grating spectra of gaseous ketene, H2CCO were recorded between 1000 and 400 cm?1, both at instrument temperature (40°C) and with cooling (?40°C). Interferometric Fourier spectra were also measured at ?70°C with resolution 0.22 cm?1 between 450 and 330 cm?1. The K structure of the fundamentals ν5, ν6, ν8, and ν9 was assigned. These fundamentals are coupled by a-axis Coriolis interactions. These couplings were analysed on the symmetric top basis for setting up the perturbation matrix and by utilizing the K-dependent Coriolis shifts of levels. A preliminary analysis of the Coriolis intensity anomalies was also undertaken.Band center values from combination differences are and . Synthetic spectra indicate the band origins of ν8 and ν9 to be close to 977.8 and 439.0 cm?1, respectively. Estimates of Coriolis coupling constants obtained from synthetic spectra are , , , and . Approximate ratios of unperturbed vibrational transition moments obtained from spectral simulations are . 相似文献
17.
The cw dye laser excitation spectrum of the vibronic band of HCF was observed between 17 188 and 17 391 cm?1 with the Doppler-limited resolution, 0.04 cm?1. The HCF molecule was produced by the reaction of discharged CF4 with CH3F, and 853 lines were observed, of which 516 transitions were assigned to K′a ← K″a = 3 ← 4, 2 ← 3, 1 ← 2, 0 ← 1, 1 ← 0, 2 ← 1, 0 ← 0, 1 ← 1, 2 ← 2, 3 ← 3, 2 ← 0, and 0 ← 2 subbands. A rotational analysis yielded the rotational constants and quartic and sextic centrifugal distortion constants for both the and states and the band origin, with good precision. The molecular constants determined reproduce the observed transition frequencies with an average deviation of 0.0038 cm?1. Small rotational perturbations in the excited state were found at J = 5, 6 and J = 10, 11 of J1,J and at J = 15, 16 of J2,J?1 levels. 相似文献
18.
Takashi Ishiwata Atsuto Tokunaga Tsutomu Shinzawa Ikuzo Tanaka 《Journal of Molecular Spectroscopy》1984,108(2):314-327
An optical-optical double-resonance technique has been applied to study the D(0u+) ion-pair state of Br2 in a one-photon resonant three-photon absorption. The OODR transition proceeds through the high vibrational level of the B3Π(0u+) state, which compromises a large Franck-Condon shift required for the excitation of Br2 from the X1Σg+ state to the D(0u+) state. Dunham parameters of the D(0u+) state, based on a global least-squares fit of 407 transitions (v′ = 0–16, J′ = 17–115), are Y00 = 49928.443(41), Y10 = 134.467(19), Y20 = ?8.71(27) × 10?2, Y30 = ?3.36(10) × 10?3, Y01 = 4.2382(15) × 10?2, Y11 = ?1.061(36) × 10?4, Y21 = ?2.00(27) × 10?6, and Y02 = ?1.93(11) × 10?8 for 79Br2 (all in cm?1, and 3σ in parentheses). The single rovibronic fluorescence spectrum of the D(0u+) state shows a transition terminating on the X1Σg+ ground state, and establishes the absolute v′ numbering on the basis of the Franck-Condon factor calculations. The v′ = 2 and 3 levels of the D(0u+) state are strongly perturbed due to the heterogeneous interaction with the 1u state correlating with the same ionic products of the D(0u+) state at the dissociation limit, . 相似文献
19.
Keiji Matsumura Kentarou Kawaguchi Keiichi Nagai Chikashi Yamada Eizi Hirota 《Journal of Molecular Spectroscopy》1980,84(1):68-73
The v = 1 ← 0 vibration-rotation bands of the NS radical in the and electronic states were observed by using a tunable diode laser. From the least-squares analysis the band origins were determined to be 1204.2755(12) and 1204.0892(19) cm?1, respectively, for and . The rotational and centrifugal distortion constants and the internuclear distance in the X2Π electronic state were obtained as follows: Be = 0.775549(10) cm?1, De = 0.00000129(33) cm?1, and , with three standard deviations indicated in parentheses. 相似文献
20.
Ch.V.S. Ramachandra Rao 《Journal of Molecular Spectroscopy》1982,95(2):239-253
The semirigid bender Hamiltonian [Bunker and Landsberg, J. Mol. Spectrosc.67, 374–385 (1977)] was used to fit the rotation-inversion energy level separations in the excited state of formaldehyde. We fix the r0(CH) bond length and allow the R(CO) bond length and (H?H) bond angle to vary with the inversion angle ρ. The fit to 64 rotation-inversion energies (with v4 and J < 4) is significantly better with a standard deviation of 0.199 cm?1 than when the rigid bender [Bunker and Stone, J. Mol. Spectrosc.41, 310–332 (1972)] is used. The barrier height to planarity is 358 cm?1 and the equilibrium ρe = 34.7°. The CO bond length is found to decrease by 0.034 from 1.3670 Å and the H?H angle by about 6 from 122.4° as the molecular configuration changes from planar to pyramidal. The rigid bender model developed earlier by Moule and Rao for formaldehyde [J. Mol. Spectrosc.45, 120–141 (1973)] is then used to fit the 32 rotation-(out-of-plane) bending energy levels (with v4 = 0 and 1) of the ground electronic state of H2CO. For this, a simple potential consisting of quadratic and quartic terms is used and the standard deviation of the fit is 0.148 cm?1. 相似文献