Infrared Spectrum of Ozone in the 4600 and 5300 cm-1 Regions: High Order Accidental Resonances through the Analysis of nu1 + 2nu2 + 3nu3 - nu2, nu1 + 2nu2 + 3nu3, and 4nu1 + nu3 Bands

The very weak bands nu1 + 2nu2 + 3nu3 and 4nu1 + nu3 of 16O3 have been observed for the first time, using the Fourier transform spectrometer (FTS) of Reims and the usual experimental setup providing a large product p x l of approximately 38 Torr x 36 m. The upper levels of these A-type bands which are rather close in energy (they appear respectively at 5291.722 and 5307.790 cm-1) belong to two different sets of interacting polyads. To correctly reproduce the rotation-vibration energy levels and account for the observed perturbations, both bands are treated in a dyad approximation: the (123) state in the Coriolis resonance with the (330) state, and the (401) state in the Coriolis resonance with the (024) state. The assignments of the rotation-vibration levels of the (123) state are confirmed by measurements of line positions of the hot band nu1 + 2nu2 + 3nu3 - nu2 which has also been observed for the first time. The fits are very satisfactory: the r.m.s. deviation for 249 energy levels of the (123) state is 2.4 x 10(-3) cm-1 and is 2.0 x 10(-3) cm-1 for 266 levels of the (401) state. These r.m.s. are near experimental accuracy. Transition moments for the three observed bands are determined from measured line intensities. Copyright 1997 Academic Press. Copyright 1997Academic Press     

Methyl Isocyanide Hot Bands in the Region 1300-1560 cm-1

The hot bands accompanying the fundamentals nu6 and nu3 of CH3NC in the region 1300-1560 cm-1 observed in high-resolution Fourier transform recordings complemented by diode laser spectra have been analyzed. The observed transitions comprise 16 subbands of the pair of perpendicular E-E bands nu6± + nu8± - nu8± and nu7-/+ + 2nu80 - nu8± whose upper states form a Fermi dyad, 18 subbands of the A1,2-E perpendicular bands nu6-/+ + nu8± - nu8±/nu7± + 2nu8±2 - nu8± with upper states forming another Fermi dyad, and 8 subbands of the bi-parallel E-E band nu3 + nu8± - nu8±. The anharmonic, Coriolis, and l-type interactions which couple these upper states with each other and with the states nu7-/+ + 2nu8±2, nu4 + 3nu8±1, and nu4 + 3nu8±3 have been included in an 18 x 18 Hamiltonian matrix whose eigenvalues model the upper levels of the observed transitions. The values of 46 upper state spectroscopic constants and interaction constants have been adjusted by least squares to 950 observed lines. The results provide a reliable quantitative picture of the interacting states and yield accurate values for the spectroscopic constants of the various states and for the anharmonic constants x68, x68 (g68), and x38. Copyright 1997Academic Press     

The Interacting v6 = 2 Levels of D3Si35Cl: A Tool to Determine Ground State Constants from High-Resolution Spectra in the 440-590 and 900-1100 cm-1 Regions

High-resolution FTIR spectra of monoisotopic D3Si35Cl have been recorded in the regions 440-590 cm-1 (nu3/nu6) and 900-1100 cm-1 (2nu6/nu3 + nu6/2nu3). A detailed rovibrational study was done for the 2nu06, 2nu-/+26, and 2nu3 overtone bands and for the 2nu+/-26-nu+/-16, 2nu06-nu-/+16, and (nu3 + nu+/-16)-nu+/-16 hot bands. For the first time the interactions occurring between the v6 = 2, v3 = v6 = 1, and v3 = 2 levels of any trideuterated silyl halide have been analyzed. The (nu3 + nu+/-16)-nu+/-16 hot band served to obtain accurate energies of the v3 = v6 = 1 level, the nu3 + nu6 combination band not being detectable on our spectra. The first experimental determination of A0 and D0K for this molecule was undertaken by a well-established method, using the nu6, 2nu+/-26-nu+/-16, and 2nu-/+26 bands. Ground state energy differences DeltaK(J) = E0(J, K) - E0(J, K - 3) were calculated for K values from 2 to 16. By a least-squares fit of 163 such differences, the A0 and D0K values thus obtained were (in cm-1): A0 = 1.4278230(8) and D0K = 5.3916(31) x 10(-6). Copyright 1999 Academic Press.     

Hyperinsulinemia is associated with the incidence of hypertension and dyslipidemia in middle-aged men

In addition to the previously observed band system nu6 + (n + 1)nu9-nnu9 with n = 0 to 7, Deltal = 0, and l = n near 611 cm-1, we have identified the nu6 + (n + 1)nu9 - (n + 2)nu9 system with n = 0 to 6, Deltal = 0, and l = n + 2 near 397 cm-1. From these bands the rovibrational levels of the states (v6, nv9) with n < 4 have been determined and spectroscopic parameters have been obtained taking into account rotational and vibrational l-type resonances. Effective anharmonicity constants x69 and g69 have been calculated also for levels with n >/= 4. Copyright 1998 Academic Press.     

Diode Laser Spectroscopy of Trifluoroethylene in the 8.6-μm Region

The two mid-infrared bands of the CF2&dbond;CHF molecule, nu5 centered at 1172.673 cm-1 and nu6 + nu9 at 1155.105 cm-1, were measured on a tunable diode laser spectrometer with a resolution near the Doppler limit. These vibrations of A' species give rise to a/b hybrid bands, even though our analysis has pointed out that the intensity of the a-type component is predominant. Most of the J and K structure has been resolved in different subbranches, and the rovibrational analysis led to the assignment of about 1400 (J 相似文献   

The Fundamental Vibrations of NC-CC-CN (Dicyanoacetylene)

In the infrared spectrum of dicyanoacetylene the rotation vibration bands nu1 - nu9/2nu5 - nu9, nu1 + nu9/2nu5 + nu9 (Fermi resonance), nu2 - nu9, nu2 + nu8, nu4, nu6 - nu9, nu6 + nu8 - nu6, nu4 - nu7, nu4 + nu7, nu4 + nu7 - nu7, nu7 + nu8 - nu7, and 2nu7 + nu8 - nu7 (I and II) have been recorded with high resolution. From these bands the vibrational levels v1 = 1, v2 = 1, v4 = 1, v6 = 1, and v7 = 1 including the corresponding effective rotational constants have been calculated. Different methods for calculating the unperturbed position of the v1 = 1 level have been compared and the unperturbed B1 has been calculated. Additional information on the rotational constants of v8 = 1 and v9 = 1 is also given. Copyright 1997 Academic Press. Copyright 1997Academic Press     

Infrared Fundamental and First Hot Bands of O12C17O Isotopic Variants of Carbon Dioxide

Infrared spectra of 16O12C17O, 17O12C17O, and 17O12C18O in a carbon dioxide sample enriched with oxygen-17 have been recorded with a resolution of about 0.0025 cm-1 in the regions of the fundamental bands, nu2 (600-800 cm-1) and nu3 (2200-2400 cm-1), and in the region of the "forbidden" band, nu1 (1200-1400 cm-1), using the long path difference Fourier transform spectrometer of the LPMA in Paris. For each species, the first hot band in the 4.5-μm region and two hot bands at least in the 15-μm region have been studied for the first time, and a simultaneous reduction of wavenumbers measured in different spectral regions has been carried out yielding new or improved spectroscopic constants. Line intensities have been measured in the region of the nu2 and nu3 bands of 16O12C17O, and the corresponding rotationless transition dipole moments and Herman-Wallis coefficients have been reported. Copyright 1998 Academic Press.     

High-Resolution Infrared Spectrum of nu5, nu4, nu3, nu4 + nu5, and 2nu4 Band Systems of Deuterobromoacetylene

High-resolution vibration-rotation spectra of gas-phase deuterobromoacetylene have been recorded in the 240-990 cm-1 infrared region. The analyzed band systems are rich in hot bands and have a high density of lines. Five band systems and a total of 124 vibration-rotation bands of the isotopic species DCC79Br and DCC81Br have been rotationally analyzed. Accurate rotational parameters and vibrational wavenumbers for 33 vibrational states of each species have been obtained from the rotational analysis. l doubling and rotational l resonance have been observed on some states and the respective resonance parameters have been obtained through nonlinear least-squares optimization. A Fermi resonance block model with perturbation terms has been used for the analysis of the vibrational states. With optimized parameters, the model produces root-mean-square deviations of observed - calculated wavenumbers of about 0.3 cm-1 for both isotopic species. Copyright 1999 Academic Press.     

The Absorption Spectrum of H2S Between 2150 and 4260 cm-1: Analysis of the Positions and Intensities in the First (2nu2, nu1, and nu3) and Second (3nu2, nu1 + nu2, and nu2 + nu3) Triad Regions

The two triad systems of hydrogen sulfide (2nu2, nu1, and nu3 near 4 μm and 3nu2, nu1 + nu2, and nu2 + nu3 near 2.7 μm) were analyzed using 14 spectra recorded at 0.0056 and 0.011 cm-1 resolution with the McMath Fourier transform spectrometer located at Kitt Peak National Observatory. Experimental upper state levels of H232S, H234S, and H233S were obtained from assigned positions (as high as J = 20 and Ka = 15 for the main isotope). These were fitted to the A-reduced Watson Hamiltonian to determine precise sets of rotational constants through J10 and up to nine Fermi and Coriolis coupling parameters. Intensities of the two H232S triads were modeled with rms values of 2.5%, using the transformed transition moment expansion with 19 terms for 568 intensities of the first triad and 11 terms for the 526 intensities of the second triad. The second derivatives of the dipole moment with respect to normal coordinates were estimated in Debye to be: 22μx = -0.004873 (90); 12μx = 0.01372 (30); and 23μz = 0.01578 (30). This confirmed that for hydrogen sulfide some of the second derivatives are larger than the first derivatives. The calculated line intensities were summed yielding integrated band strengths (in cm-2/atm at 296 K) as follows: 0.3315 for 2nu2, 0.4522 for nu1, 0.1201 for nu3, 0.0303 for 3nu2, 1.820 for nu1 + nu2, and 2.869 for nu2 + nu3. In addition, the hot band transitions were identified in both regions. Finally, a composite database of hydrogen sulfide line parameters was predicted for the 5- to 2.5-μm region. Copyright 1998 Academic Press.     

Fourier Transform Infrared Emission Spectroscopy of the C4Delta-X4Phi, G4Phi-X4Phi, and G4Phi-C4Delta Systems of TiCl

The emission spectrum of TiCl has been investigated in the 3000-12 000 cm-1 region at high resolution using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a flowing mixture of TiCl4 and helium. The observed bands have been classified into three electronic transitions, C4Delta-X4Phi, G4Phi-X4Phi, and G4Phi-C4Delta. In the 3000-3500 cm-1 region, four bands with R heads at 3368.7, 3331.8, 3291.9, and 3243.4 cm-1 have been assigned as the 0-0 bands of the 1/2-3/2, 3/2-5/2, 5/2-7/2, and 7/2-9/2 subbands, respectively, of the C4Delta-X4Phi transition. To higher wavenumbers, four transitions with 0-0 R heads at 10 930.7, 10 921.3, 10 906.5, and 10 886.9 cm-1 have been assigned as the 3/2-3/2, 5/2-5/2, 7/2-7/2, and 9/2-9/2 subbands, respectively, of the G4Phi-X4Phi system of TiCl. Four additional bands with 0-0 R heads at 7568.8, 7596.4, 7622.2, and 7651.7 cm-1 have been identified as the 1/2-3/2, 3/2-5/2, 5/2-7/2, and 7/2-9/2 subbands of the G4Phi-C4Delta transition, respectively. A rotational analysis of a number of vibrational bands of these transitions has been obtained and molecular constants have been extracted. The lowest 4Phi state has been assigned as the ground state of TiCl, by analogy with our recent work on TiF (R. S. Ram and P. F. Bernath, J. Mol. Spectrosc., in press). The correspondence between the electronic states of TiCl, TiF, TiH, and Ti+ is also discussed. Copyright 1997 Academic Press. Copyright 1997Academic Press     

Analysis of the nu8 + nu9 Band of HNO3, Line Positions and Intensities, and Resonances Involving the v6 = v7 = 1 Dark State

Using a high-resolution (R = 0.0025 cm-1) Fourier transform spectrum of nitric acid recorded at room temperature in the 1100-1240 cm-1 region, it has been possible to perform a more extended analysis of the nu8 + nu9 band of HNO3 centered at 1205.7075 cm-1. As in a recent analysis of this band [W. F. Wang, P. P. Ong, T. L. Tan, E. C. Looi, and H. H. Teo, J. Mol. Spectrosc. 183, 407-413 (1997)], the Hamiltonian used for the line positions calculation takes into account, for the upper state, the DeltaK = +/-2 anharmonic resonance linking the rotational levels of the v8 = v9 = 1 "bright" vibrational state and those of the "dark" v6 = v7 = 1 vibrational state. More than 4800 lines were assigned in the nu8 + nu9 band, which involve significantly higher rotational quantum numbers than in previous works. On the other hand, and surprisingly as compared to previous studies, the nu8 + nu9 band appears to be a hybrid band. In fact, nonnegligible B-type transitions could be clearly identified among the much stronger A-type lines. Accordingly, a set of individual line intensities were measured for lines of both types and were introduced in a least-squares fit to get the A- and B-type components of the transition moment operator. Finally, a synthetic spectrum of the 8.3-μm region of HNO3 has been generated, using for the line positions and line intensities the Hamiltonian constants and the expansion of the transition moment operator which were determined in this work. In this way, the B-type and the A-type components of the nu8 + nu9 band appear to contribute for about (1/4) and (3/4), respectively, to the total band intensity. Copyright 1999 Academic Press.     

The crystal structure of the L1 metallo-beta-lactamase from Stenotrophomonas maltophilia at 1.7 A resolution

The emission spectrum of TaO, excited in a tantalum hollow cathode lamp, has been observed at high resolution using a Fourier transform spectrometer. In addition to previously known transitions, a number of new bands have been identified and assigned as belonging to two new electronic transitions: H2Pi1/2-X2Delta3/2 and K2Phi5/2-X2Delta3/2. A rotational analysis ofthe 0-0 and 0-1 bands of the H2Pi1/2-X2Delta3/2 transition and of the 0-1, 1-2, 0-0, 1-0, and 2-1 bands of theK2Phi5/2-X2Delta3/2 transition has been carried out, providing the following equilibrium constants for the ground X2Delta3/2 state:omegae = 1028.9060(15) cm-1, omegaexe = 3.58928(66) cm-1, Be = 0.40289737(139) cm-1, alphae = 0.00185445(83) cm-1, andre = 1.6873430(29) ?. The principal molecular constants for the H2Pi1/2 state are T00 = 20 634.32758 (40) cm-1,B0 = 0.3766867(31) cm-1, and r0 = 1.7450604(72) ?, while the equilibrium constants for the K2Phi5/2 state areomegae = 905.4549(15) cm-1, omegaexe = 3.67601(64) cm-1, Be = 0.37965102(36) cm-1, alphae = 0.00189370(21) cm-1, andre = 1.7382343(8) ?. Although the H2Pi1/2 and K2Phi5/2 states have been observed previously in matrix isolation experiments, our work on these states is the first in the gas phase. Copyright 1998 Academic Press.     

A panel set for epitope analysis of myeloperoxidase (MPO)-specific antineutrophil cytoplasmic antibody MPO-ANCA using recombinant hexamer histidine-tagged MPO deletion mutants

The nu2/nu4 dyad of arsine, AsH3, has been investigated between 875 and 1100 cm-1 by laser sideband spectroscopy. In total 189 transitions have been observed with sub-Doppler resolution ( approximately 300 kHz) and measured to an absolute accuracy of about 100 kHz. These data may be useful to serve as a secondary frequency standard. Our observations include four perturbation-allowed transitions with Delta(k - l) = 3. Saturation spectra of dipole forbidden transitions had not been previously reported for arsine. Quadrupole hyperfine structure, as well as vibration-rotation splitting of |k - l| = 3N levels in both fundamentals, has been analyzed. Combining our results with MW and RF data (239 frequencies) reported in the literature, a total of 882 transition frequencies were available to fit 15 ground state parameters and 48 excited state parameters of the nu2/nu4 dyad. The standard deviation of the fit is 245 kHz. Copyright 1998 Academic Press. Copyright 1998Academic Press     

High-Resolution Infrared Spectrum of Vinyl Fluoride at 500 cm-1

The infrared spectrum of vinyl fluoride (CH2=CHF) has been investigated in the region 390-590 cm-1 at room temperature and at a resolution of 0.0016 cm-1 using a Fourier transform spectrometer. The rovibrational analysis of the spectral features allowed us to assign about 11 000 lines (J 相似文献   

Analysis of Line Positions and Strengths of H216O Ground and Hot Bands Connecting to Interacting Upper States: (020), (100), and (001)

High-resolution spectra of H216O were recorded with a Fourier-transform spectrometer covering transitions in the (020)-(010), (100)-(010), and (001)-(010) bands from 1100 to over 2300 cm-1. Also included in the study were previously reported measurements of these bands and measurements of the (020)-(000), (100)-(000), and (001)-(000) bands from 2620 cm-1 to 4500 cm-1. The linestrengths were fitted to a model which takes into account the interactions between the vibrational states (020), (100), and (001). The model included dipole moment matrix elements (also referred to as transition elements) represented by 19 expansion coefficients for B-type transitions and 14 expansion coefficients for A-type band transitions. The most satisfactory results were obtained when the relative signs and values of the leading dipole moment terms of each of the three "hot" bands were as follows: u(020-010) = 1.936(97) x 10(-1) D, u(100-010) = 3.876(19) x 10(-2) D, and u(001-010) = 2.523(75) x 10(-2) D. Hot water emission experimental frequencies from other studies were included in an analysis to obtain rotational energies for levels up to high J and/or Ka of the (020), (100), and (001) vibrational states. The results from this study provide a more accurate representation of the parameters than those available at present for the six bands. Copyright 1999 Academic Press.     

Simultaneous Analysis of the 2nu2, nu1, and nu3 Bands of Hydrogen Telluride

Spectra of a natural sample of hydrogen telluride as well as a spectrum of monoisotopic H2 130Te have been recorded by means of Fourier transform spectrometry with a resolution of 0.003 cm-1 in the spectral domain 7.5-4.3 μm where it is easy to observe the main absorbing bands nu1 and nu3. We have located and assigned for the first time the 2nu2 band which appears in the lower wavenumber range of the recorded spectral domain near 1700 cm-1. It proved necessary to treat simultaneously the three states (020), (100), and (001). nu1 and nu3 are indeed Coriolis-coupled vibration-rotation bands and it was observed that a few rotational levels of (001) could not be fitted to within their experimental accuracy without considering the second-order Coriolis interaction between the rotational levels of (020) and (001). In this way all the experimental levels were calculated to within the experimental uncertainty, and precise sets of vibrational energies and rotational and coupling constants were obtained for the seven most abundant H2Te isotopic species, namely H2 130Te, H2 128Te, H2 126Te, H2 125Te, H2 124Te, H2 123Te, and H2 122Te. For the most abundant isotopic species H2 130Te the bands centers arenu0 (2nu2) = 1715.9568, nu0 (nu1) = 2065.2709, nu0 (nu3) = 2072.1101 cm-1. Copyright 1997Academic Press     

Hot Bands of Water up to 6nu2-5nu2 in the 933-2500 cm-1 Region

Emission spectra have been recorded for hot water at temperatures up to 1550 degreesC. Separate spectra have been recorded in the 800-1900 and 1800-2500 cm-1 range. Assignments are made using a linelist generated from high accuracy, variational nuclear motion calculations, and energy differences. The spectra contain many hot bending transitions of the form (0n0)-(0n-10), where states up to n = 6 have been assigned. Detailed analysis shows that the spectra contain lines from 34 separate vibrational bands including other hot bending transitions and the difference bands (030)-(100), (110)-(020), (011)-(020), (100)-(010), (040)-(110), (040)-(011), (120)-(030), (012)-(030), (011)-(100), (110)-(001), and (101)-(110), all of which have not been observed previously. From a total of 8959 lines recorded, 6810 have been assigned; 4556 of these lines are new. These spectra represent the first detection of the (060) vibrational band, for which a band origin of 8870.54 +/- 0.05 cm-1 is determined. The (050) band origin is confirmed as 7542.40 +/- 0.03 cm-1. The assignments extend the range of J and Ka values observed for the bending states, particularly for (050) and (060), where 63 and 27 different rotational levels, respectively, have now been observed; 53 frequencies given in HITRAN are corrected. Copyright 1999 Academic Press.     

Structure and polymorphism of the upstream region of the pfg27/25 gene, transcriptionally regulated in gametocytogenesis of Plasmodium falciparum

Multi-photon transitions with two simultaneously interacting IR laser fields lead to final excited states with frequencies nnu = n1nu1 + n2nu2, with n the total number of photons absorbed and (n, n1, n2) = (2, 1, 1), (3, 2, 1), (4, 1, 3), etc. The nature of the actual transition is determined by shift measurements, where the lasers are frequency-tuned by deltanui in opposite directions keeping the sum frequency, nnu, resonant with the molecular transition. This technique opens a new spectral range for multi-photon transitions and a unique identification of the observed features. For n1 and n2 both positive the excitation will lead to a "normal" up-up multi-photon transition. Many three- and four-photon transitions in the nu3 vibrational ladder of SF6 could be resolved with a resolution of 1 MHz, as well as four new two-photon transitions. As long as n1 + n2 >/= 0, one of the two ni may be negative resulting in an, e.g., up-down excitation pathway with its particular selection rules. The up-down excitations are demonstrated both for one- and two-photon transitions using the frequency shift technique. The different possible excitation schemes which meet the resonance condition for these transitions lead to interference effects and local couplings to highly excited states. Changes in resonance frequency for a one-photon transition (n = 1), due to these effects, are demonstrated. Evidently, the radiative coupling of participating levels to high-lying or quasi-continuum states may drastically change for different deltanui leading both to ac Stark shift and transition probability variations.     

Can Isotopic Substitution Change a Bright State into a Dark State? The Case of the v3 = 1 State of FClO3

High-resolution infrared spectra of monoisotopic samples of F35Cl18O3 and F37Cl18O3 have been recorded with the purpose of analyzing the nu3 fundamental at 535 cm-1. However, this band could not be observed whereas it had been seen and studied earlier in F35Cl16O3. To determine the parameters of the v3 = 1 state, indirect methods were used. Hot bands nun + nu3 - nu3 (n = 1 or 2) were first analyzed and their LSCD (Lower State Combination Differences) yielded rotational parameters of nu3. Then, with the help of nu1 + nu3, all rovibrational parameters of nu3 were obtained. Similar methods were applied to spectra of F35Cl16O3 and F37Cl16O3 to prove that the parameters of nu3 obtained in this fashion are identical to those determined directly for these isotopomers and are even more comprehensive. It is shown that the different character of nu3 in the two 18O and in the two 16O isotopomers is due to the fact that the former are much closer to a spherical top molecule ((A0 - B0)/A0 = 0.015). This is not only reflected in intensities different by two orders of magnitude but also in the very different values of alpha3B in these two pairs. Copyright 1997 Academic Press. Copyright 1997Academic Press     

The High-Resolution Spectrum of Water Vapor between 11 600 and 12 750 cm-1

The water vapor linestrengths in the region of the 3nu + delta resonance polyad of interacting vibrational states (the corresponding upper states are (310), (211), (112), (013), (131), (230), (032), and (051)) have been analyzed leading to accurate dipole moment transition parameters. The effective rotational Hamiltonian constants used to calculate the vibration-rotation wavefunctions (J.-M. Flaud, C. Camy-Peyret, A. Bykov, O. Naumenko, T. Petrova, A. Scherbakov, L. Sinitsa, 1994. J. Mol. Spectrosc. 183, 300-309) take into account both strong centrifugal distortion effects and dark states presence. These effects are known to be important for the highly excited vibrational states of water-like molecules. The input data set included the line intensities measured by Toth (R. Toth, 1994. J. Mol. Spectrosc. 166, 176-183) and the line intensities of the weak bands 2nu1 + 3nu2, 3nu2 + 2nu3, and 3nu1 + nu2 derived from peak absorptions of a spectrum recorded at a pressure of 17.0 Torr and a path length of 434 m. The parameters of the effective dipole moment operator determined by least square fitting give a very satisfactory agreement with experimental values since the mean error for the 876 experimental linestrengths is only 3.9%. It is worth noticing that such an agreement could be reached only because high-order resonance couplings with dark states were explicitly taken into account. Copyright 1997 Academic Press. Copyright 1997Academic Press