Overtone ammonia

Unfortunately, liquid ammonia possesses a very intense absorption band at 15,320 A. (2 i and/or 2vz) so that this region is inaccessible for quantitative measurements even with a 1 mm. cell. If ND8 is used as the solvent instead of NH8, no intense overtone or combination bands of the solvent occur in the spectral region of interest (Figure 1). The spectra of dilute solutions of lithium, sodium, potassium, calcium, and barium in liquid ND8, and the perturbations arising from concentration changes, temperature changes, and the presence of inert salts have been investigated. 

In isolation, the BHT ion is tetrahedral, and consequently only two fundamentals, the asymmetric BH stretch (V3) and asymmetric BH4 deformation (V4) are IR active for the isolated ion, whereas all four fundamentals are Raman active. The Raman active fundamentals were characterized in liquid ammonia solutions, whereas IR spectra of thin films of NaBH4 on alkali halide crystals or diluted in an alkali halide host crystal have been reported ". Raman and IR studies focused specifically on NaBH4 and LiBH4 have also been reported. The vibrational modes in borohydrides are of three distinct types librational (below 1000 cm ), B-H bending (1127 cm ) and B-H stretching (2200-2400 cm ). The overtone of the deformation mode (2V4) occurs around 2228 cm ... 

As it is seen on Table 1, the vibrational frequencies of ammonia are adequately reproduced by the PES given in Eqs. 4, 5, and in Table 2, both for the fundamentals, the highly excited inversion levels, and the overtones and combinations of all vibrational modes. From a comparison with our preceding work [13] it is seen that some of the force constants for ammonia are different from our previous work. This is... 

Aneja, V.P., B.P. Malik, Q. Tong, D. Kang, and J.H. Overton, Measurement and Modelling of ammonia emissions at waste treatment lagoon-atmospheric interface. Water, Air, and Soil Pollution, 1, 177-188, 2001d. 

In another study (13), a semicarbazide coating was prepared by dissolving 100 mg of semicarbazide hydrochloride in 10 ml of 1 1 acetone/ethanol, followed by the addition of 5 ml of 6 M ammonia solution. The clear solution was allowed to stand to ensure neutralization of the hydrochloric acid before application to the crystal electrodes. The coated 9 MHz crystal was driven at its third overtone of 27 MHz. The detector had a sensitivity of 12.4 Hz jjI and a linear response in the concentration range 5.50 tjg 1. the highest response was obtained in a dry nitrogen stream at a flow rate of 90 ml min, and decreased to about 33% in a wet air stream (58% relative humidity) at a flow rate of 200 ml min". The relative sensitivities to the potential intererences studied (chloroform, acetaldehyde, ethanol, acetone, n-octanol, ethyl-butyrate and n-hexylacetate) ranged from 0.000000 to 0.000029 compared to a relative response of one to acetoin. 

N-H (2v), RNHj N-H (2v), secondary amine as (R-NH-R), morpholine, first overtone band intensity comparisons, CCI4 solution N-H (2v) for NH3 (ammonia) in water... 

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