Ammonia absorption spectrum

Microwave spectroscopy began in 1934 with the observation of the -20 GHz absorption spectrum of ammonia by Cleeton and Williams. Here we will consider the microwave region of the electromagnetic... 

As an example, five different synthetic colorants (Tartrazine, Sunset Yellow, Ponceau 4R, Amaranth, and Brilliant Blue FCF) from drinks and candies were separated on a polyamide adsorbent at pH 4, eluted with an alkaline-ammonia solution. By another method, 13 synthetic food colorants were isolated from various foods using specific adsorption on wool. After elution with 10% ammonia solution and gentle warming, an absorption spectrum of the resulting colorant solution was recorded, compared to the reference spectra of pure colorants, and identified by linear regression analysis. ... 

The absorption spectrum of radiation-produced eam is identical to that in dilute metal-ammonia solutions. It has a broad, structureless absorption in the red and IR, with a peak at about 1.88 pm and a half-width of 0.2 eV on the high-energy side. The absorption is intense with max = 4.8 x 104 M 1cm 1, giving an... 

The model predicts a red shift of the absorption spectrum with temperature for both eh and eam. However, in ammonia the effect is about four times bigger, because the volume expansion of the cavity is the main contributing factor. In water, the temperature variation of the... 

TlSe was also deposited from a solution of TI2SO4 complexed with triethanolamine and ammonia and selenosulphate at 30°C [49]. Tetragonal TlSe was identified by XRD. The bandgap was estimated at 1.12 eV however, the absorption spectrum appears to show two transitions—one (possibly indirect) at > 0.9 eV and another at = 1.3 eV. The films were p-type, with a resistivity of Kl O-cm. Considering the high carrier concentration measured (almost 10 ° cm ), this resistivity value appears unusually high. 

It appears that most reported CD CdSe films are size-quantized, with crystal sizes of < 10 nm. There are some exceptions. Films deposited via an ion-by-ion mechanism at high temperature possess larger crystal size and show no size effects [8], Films deposited from an ammonia/selenosulphate bath were reported with a bandgap, measured from the absorption spectrum, typical of bulk CdSe (ca. 1.74 eV) [22]. The CdSe in this study was grown at 80°C from a solution containing 48 mM Cd and 2.1 M NH3. Taking into account the additional complexing power of the selenosulphate, such a solution may be close to the transition between a hydroxide mechanism and an ion-by-ion one. 

Fig. 26 Fourier transform spectrum of v2 of ammonia. Trace (a) is a section of the infrared absorption spectrum of ammonia recorded on a Digilab Fourier transform spectrometer at a nominal resolution of 0.125 cm-1. In this section of the spectrum near 848 cm-1 the sidelobes of the sine response function partially cancel, but the spectrum exhibits negative absorption and some sidelobes. Trace (b) is the same section of the ammonia spectrum using triangular apodiza-tion to produce a sine-squared transfer function. Trace (c) is the deconvolution of the sine-squared data using a Jansson-type weight constraint.

Finally, a striking property of metal-ammonia solutions is the large expansion of the liquid due to the solvated electrons. The apparent volume of the solvated electron remains roughly constant up to the metallic range, then shows a slight increase. It is about 100 cm3 mol. It is this effect that has led to the hypothesis that the electron forms a cavity for itself a cavity of radius 3.2 A accounts quantitatively for the excess volume. A model in which the electron moves in a cavity, and the surrounding liquid is polarized or solvated as it is round a cation, was first put forward by Jortner (1959), who showed that it was able to account for the absorption spectrum. Jortner s model, as modified by Mott (1967), Cohen and Thompson (1968) and Catterall and Mott (1969), will now be described. 

The z-phase in a chromium-vanadium system was quite different from CrV04 with respect to the x-ray diffraction pattern, ESR absorption spectrum, and infrared absorption spectrum and could be reduced with ammonia at 400°C., thus differing from CrV04. Taking into account the infrared absorption spectra of a chromium-vanadium system, the... 

Comparison of the electrical conductivities of chromium penta-phenyl hydroxide, sodium hydroxide and ammonia in absolute methyl alcohol and in methyl alcohol-water solution, shows that the former is a very strong base. In aqueous methyl alcohol solution the chromium compound does not appear to approach the limiting value with increasing dilution. The ultra-violet absorption spectrum examined in absolute ethyl alcohol solution resembles that of chromic acid and the dichromates, but the absorption is noticeably greater in the case of the organic compound. 

Absorption Spectrum of e aq. The absorption spectrum of the hydrated electron is shown in Figure 1. The evidence that this spectrum is that of eaq is at least four-fold. First, the spectrum is suppressed by known electron scavengers, such as H30+, 02, N20 (4, 18). Second, it resembles in form the absorption bands of the solvated electron in liquid ammonia and methylamine (4, 18). Third, the rate constants calculated from the decay of this absorption in the presence of scavengers... 

Figure 6. Absorption spectrum of potassium amide in liquid ammonia (

The compound responsible for the 265 m/z absorption has not yet been identified. The obvious assignment to sym-diethylhydrazine is contradicted by the absorption spectrum of an authentic sample of the hydrazine (supplied by Merck, Sharp and Dohme, Montreal), which shows no sign of a peak at 265 m/z. Instead, the spectrum in ethylamine solvent has a broad maximum at 358 m/z and rises steeply near the solvent cutoff at 250 m/z. We assume, therefore, that in Reaction 2, the ethylamine radical is scavenged by the solvent, to yield other ultimately stable products. In liquid ammonia, hydrogen and amide appear to be the only decomposition products, implying that the process H + NH8 - H2 + NH2 does not occur. The relative inefficiency of this process compared to H atom recombination in liquid ammonia is also indicated by radiation chemical studies (6). 

Vaida, V., McCarthy, M.I., Engelking, P.C., Rosmus, P., Werner, H.-J., and Botschwina, P. (1987). The ultraviolet absorption spectrum of the A1A2 <— X1A1 transition of jet-cooled ammonia, J. Chem. Phys. 86, 6669-6676-... 

Schnepp and Dressier98 photolyzed ammonia in an argon matrix at 4.2°K. They observed the electronic absorption spectrum of NH and NH2. It was concluded that NH was produced only with light of wavelength below 1550 A., whereas NH2 was produced with radiation both below and above 1550 A. 

Since the suggestion of the sequential QM/MM hybrid method, Canuto, Coutinho and co-authors have applied this method with success in the study of several systems and properties shift of the electronic absorption spectrum of benzene [42], pyrimidine [51] and (3-carotene [47] in several solvents shift of the ortho-betaine in water [52] shift of the electronic absorption and emission spectrum of formaldehyde in water [53] and acetone in water [54] hydrogen interaction energy of pyridine [46] and guanine-cytosine in water [55] differential solvation of phenol and phenoxy radical in different solvents [56,57] hydrated electron [58] dipole polarizability of F in water [59] tautomeric equilibrium of 2-mercaptopyridine in water [60] NMR chemical shifts in liquid water [61] electron affinity and ionization potential of liquid water [62] and liquid ammonia [35] dipole polarizability of atomic liquids [63] etc. 

To determine the photoinduced structure, the orange crystals that were formed after irradiation of benzene solutions of 6-phenoxy-5,12-naphthacenequinone were used.46 It turned out that the elemental composition of the photoinduced form coincided with the ana-quinone composition. In addition, the interaction of 6-phenoxy-5,12-naphthacenequinone with ammonia and aniline in benzene resulted in the formation of compounds that were identified as derivatives of ana-naphthace-nequinone by the counter synthesis. The ana structure of the photoinduced form was supported by the similarity of the absorption spectrum of the ana form to the spectra of unsubstituted and 5-bromo derivatives of 6,12-naphthacenequinone46 as well as by the analysis of the IR spectra of initial and photoinduced forms of 6-phenoxy-5,12-naphthacenequinone. 4... 

---