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The parallel vibration-rotation band ν(4) of methyl isocyanide (CH(3)NC), with a band center at 944.9 cm(-1), was studied by FTIR spectroscopy between 890 and 980 cm(-1) in order to improve the ground-state rotational constants. Such improvement is essential for the scheduled studies of excited vibrational levels and their mutual anharmonic resonances occurring at higher values of the K rotational number. Ground-state combination differences generated from this band, spanning values of J/K from 0 to 85/13, were combined with rotational data from the literature and newly measured rotational transitions, extending the J/K range from 3/0 up to 31/14, and fitted simultaneously with a fully quantitative reproduction of the data. The infrared data of the ν(4) band were analyzed together with rotational data of the ν(4) = 1 level, spanning values of J/K from 4/0 to 14/12. The fit in the approximation of an isolated vibrational state, with the transitions perturbed by weak local resonances excluded, yields reproduction of the data within experimental uncertainties.

The infrared spectrum of the C–H bending vibration band v 4 of chloroform around 1220 cm−1 has been measured with a Fourier transform spectrometer at an instrumental resolution of 0.0018 cm−1. An isotopically pure sample of CH35Cl3 was used. More than 3000 lines were assigned in the very congested spectrum. In the analysis the ground state rotational constants were fixed. The model included -resonance and altogether 16 free parameters. The fit gave, for example, the molecular parameters v o=1220.33803(5) cm−1, =0.068 850 (37)×10−3 cm−1, =0.012 37(17)×10−3 cm−1, (Cζ)4=0.056 036 2(18) cm−1 and q 4=0.17756 (15)×10−3 cm−1.

The high resolution (0.0010cm - 1 ) Fourier transform infrared spectra of the partially deuterated methyl iodide molecules CH 2 DI and CHD 2 I have been recorded and analysed in the v 3 band regions around 510cm - 1 . The fundamental band v 3 is associated with the stretching of the C-I bond and the spectra appear therefore as an asymmetric rotor hybrid a/b-type band and hybrid a/c-type band for CH 2 DI and CHD 2 I, respectively. About 4700 transitions in the case of CH 2 DI and about 3900 transitions in the case of CHD 2 I have been assigned. The ground state rotational constants of CH 2 DI and CHD 2 I have been obtained using the ground state combination differences calculated from the assigned v 3 transitions and 16 microwave transitions from literature. The S reduced Watson's Hamiltonian has been used in the calculations. In addition, the upper state parameters describing the v 3 = 1 vibrational states of these molecules have been determined. The obtained ground state constants as well as the upper state parameters have been compared to the corresponding constants of the symmetric top species CH 3 I and CD 3 I.

A series of samples from different growth bands of Porites coral skeleton were studied using Raman, infrared reflectance methods. The Raman spectra proved that skeleton samples from different growth bands have the same mineral phase as aragonite, but a band at 133 cm(-1) for the top layer shows a transition from similar to 120 cm(-1) for vaterite to similar to 141 cm(-1) for aragonite. It is inferred that the vaterite should be the precursor of aragonite of coral skeleton. The positional shift in the infrared spectra of the skeleton samples from growth bands correlate significantly to their minor elements (Li, Mg, Sr, Mn, Fe and U) contents. Mg, Sr and U especially have significant negative correlations with the positions of the antisymmetric stretching band v(3) at similar to 4469 cm(-1). And Li shows a high negative correlation with v(2) band (similar to 855 cm(-1)), while Sr and Mn show similar negative correlation with v(4) band (similar to 712 cm(-1)). And Mn also shows a negative correlation with v(1) band (similar to 1082 cm(-1)). A significantly negative correlation is observed for U with v(1) + v(4) band (similar to 1786 cm(-1)). However, Fe shows positive correlation with v(1), v(2), v(3), v(4) and v(7) + v(4) bands shifts, especially a significant correlation with v(1) band (similar to 1082 cm(-1)). New insights into the characteristics of coral at different growth bands of skeleton are given in present work. (C) 2013 Elsevier B.V. All rights reserved.

The far-infrared spectra of Li 0.5+0.5 a Fe 2.5−1.5 a Ti a O 4 reveal two prominent bands v 1 and v 2 and two weak bands v 3 and v 4 in the 700−200 cm −1 range. The high frequency bands v 1 and v 2 are assigned to tetrahedral metal complexes. On the basis of the analysis of the IR bands and their correlation with the cation distribution, the band v 3 is assigned to octahedral divalent metal ion-oxygen complexes, while the lowest frequency band v 4 is attributed to the lattice vibrations in the mixed ferrites. The splitting of the IR spectral band is explained on the basis of Fe 2+ ion concentration.

The fundamental band v 6, its hot band 2v 6-v 6 and the overtone band 2v 6 of 12CH3I were assigned. Using the lines of these three bands, ground state combination differences that differ in K by three were calculated for eight K value pairs from (3,0) to (10,7). The ground state constants A 0, D K 0 and H K 0 of 12CH3I were then determined and the results are A 0 = 5·173 9358(10)cm-1, D K 0 = 87·63(3) 10-6cm-1 and H K 0 = 4·53(22)10-9cm-1. The constant H K 0 was determined for the first time.

The Fourier transform infrared spectrum of acetylene between 2500 cm-1 and 2800 cm-1 has been studied at the Doppler limited resolution of 0·0070 cm-1. The combination band v 2 + v 1 5 and the hot bands (v 2 + 2v 5)2,0 ← v 1 5, v 1 ← v 1 5, v 3 ← v 1 4 and (v 2 + v 4 + v 5)2,0 ← v 1 4 have been analysed considering especially the rotational and vibrational l-type resonances. Also the Fermi-type resonance between the υ3 = 1 energy level and the Σ+ u component of the υ2 = υ4 = υ5 = 1 level has been explicitly taken into account. As a result, the vibrational and rotational constants and the resonance parameters for the bands investigated have been obtained.

The dye laser excitation spectrum of the Swan band ( v ′ − v ″ = 1 − 0) has been observed with Doppler-limited resolution. The C 2 molecule was generated by the reaction of microwave discharge products of CF 4 with CH 4 . The high sensitivity of laser excitation spectroscopy has enabled us to observe not only ΔΩ = 0 transitions, but also ΔΩ = ± 1 transitions and to determine molecular constants including the spin-orbit coupling constant for both the d 3 Π g and a 3 Π u states. The parameters thus obtained for a 3 Π u were favorably compared with those previously obtained from the Ballik-Ramsay band. The present results on the d 3 Π g v = 1 state were combined with those of an earlier Fourier spectroscopic study on the Swan band ( v ′ − v ″ = 0 − 0) to derive equilibrium molecular constants for the d 3 Π g state. The contributions of the spin-rotation interaction and the centrifugal correction for the spin-orbit coupling to the energy levels in a 3 Π state have been discussed in detail.

Four fundamental bands in the infrared spectrum of 1,1-ethylene-d2 have been studied at a resolution of ca. 0·05 cm-1: the two type-B bands v 6 and v 10 and the two type-C bands v 7 and v 8. Analysis of a set of 409 ground state combination differences enables a complete set of ground state rotational and quartic distortion constants to be determined. The effect of the a-axis Coriolis interactions between the four bands is analysed, and upper state vibrational and rotational parameters for all four bands are obtained. Two localized higher order Coriolis perturbations are identified and characterized, and the band centre of the inactive twisting vibration v 4 is estimated. From the overlapping and weak type-A band v 3, a few upper state parameters are determined.

Resonance Raman spectra of manganese (III) etioporphyrin I complexes have been obtained with laser excitation in the regions of the bands III and IV, and bands V and Va of the atypical visible absorption spectra of these metalloporphyrins. Excitation profiles in the latter region are interpreted as indicating nonadiabatic coupling between V and Va as well as vibronic activity of some totally symmetric modes. The Raman data support assignment of bands III and IV to the 0–0 and 0–1 components of the Q band. Although bands V and Va are assigned to a charge transfer transition mixed with the main π→π* transition, no selective enhancement of low frequency metal–ligand vibrations attributable to the charge transfer contribution of band V was observed.

The vibro-rotational spectrum of CF3Br in natural isotopic abundance has been recorded in the 14 μm region using a tunable diode laser spectrometer. The difference band v 1-v 3 (around 732 cm-1), the overtone 2v 3, as well as the hot-band 3v 3-v 3, (both around 700 cm-1) of both isotopic species, CF3 79Br and CF3 81Br, were analysed. The K-structure could be resolved for most of the bands observed. Accurate molecular constants for the v 3, 2v 3 and 3v 3 levels were determined from a least squares fit of the observed transition frequencies. The validity of the additivity rule for α A and α B constants is discussed in general and in particular for all parallel bands of CF3Br which involve the v 3 vibration.

Spectroscopic evidence is presented for the occurrence of a number of asymmetric complex cations, of formula (B 1 B 2 ) + where B 1 and B 2 differ, and may be pyridine, 4-methylpyridine, 2,6- and 3,5-dimethylpyridine, 2,4,6-trimethyl-pyridine, 2-fluoropyridine, 3-chloropyridine or quinoline. In the H-bridged cations, the NH stretching band v s is doubled, the ratio of the intensities of the components varying regularly with AΔp K a of the component bases. In the D-bridged cations, only a single v s band is observed. All features in the spectra evolve continuously from those of the symmetric cations (B 1 = B 2 ).

Four parallel vibration-rotation bands of CD 3 F have been measured, and much of their fine structure has been resolved. In some of these bands, the K splitting of the central Q branches has been measured, and in one case the P and B lines of the subbands, corresponding to different K values, have been analysed. Eight perpendicular type bands of CD 3 F have been measured, and seven have been analysed. One of these, v 4 , shows much P-R structure of the subbands. Values have been derived for the rotational constants, Coriolis coefficients, and the α values which relate the rotational constants in different vibrational levels. The value found for A o is 2.56 1 cm -1 . One parallel and two perpendicular bands of methyl fluoride have been analysed, and the results have been considered with previous data on this molecule to estimate the molecular constants. The band v 5 shows an unusual type of perturbation which appears to affect the two sides of the band in different ways. The value found for A 0 is 5.08 1 cm -1 . The results show again, as found with other methyl halides, that interactions between energy levels often lead to perturbations which complicate the determination of the molecular constants.

The inelastic neutron scattering (INS) spectrum (350–2000 cm −1 ) of potassium hydrogen dichloromaleate (solid slate) has been obtained. Two of the normal modes of vibration of the hydrogen bond [γ(OHO) and δ(OHO)] were observed and assigned. No INS band v as (OHO) was observed in the region 500–1300 cm −1 . This conflicts with expectations from infrared data.

Corrections are made in some data given earlier on the vibration-rotation band v 1 of methyl iodide.