Spectrum ammonia

Still another type of adsorption system is that in which either a proton transfer occurs between the adsorbent site and the adsorbate or a Lewis acid-base type of reaction occurs. An important group of solids having acid sites is that of the various silica-aluminas, widely used as cracking catalysts. The sites center on surface aluminum ions but could be either proton donor (Brpnsted acid) or Lewis acid in type. The type of site can be distinguished by infrared spectroscopy, since an adsorbed base, such as ammonia or pyridine, should be either in the ammonium or pyridinium ion form or in coordinated form. The type of data obtainable is illustrated in Fig. XVIII-20, which shows a portion of the infrared spectrum of pyridine adsorbed on a Mo(IV)-Al203 catalyst. In the presence of some surface water both Lewis and Brpnsted types of adsorbed pyridine are seen, as marked in the figure. Thus the features at 1450 and 1620 cm are attributed to pyridine bound to Lewis acid sites, while those at 1540... 

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... 

On heating the pentahydrate, four molecules of water are lost fairly readily, at about 380 K and the fifth at about 600 K the anhydrous salt then obtained is white the Cu " ion is now surrounded by sulphate ions, but the d level splitting energy does not now correspond to the visible part of the spectrum, and the compound is not coloured. Copper(Il) sulphate is soluble in water the solution has a slightly acid reaction due to formation of [CufHjOijOH] species. Addition of concentrated ammonia... 

Does the NMR spectrum shown in Figure 22 10 correspond to that of 1 amino 2 methyl 2 propanol or to 2 ammo 2 methyl 1 propanoD Could this compound be prepared by reaction of an epoxide with ammonia" ... 

The word laser is an acronym derived from light amplification by the stimulated emission of radiation . If the light concerned is in the microwave region then the alternative acronym maser is often used. Although the first such device to be constructed was the ammonia maser in 1954 it is the lasers made subsequently which operate in the infrared, visible or ultraviolet regions of the spectrum which have made a greater impact. 

Perhaps the most convincing evidence for nucleophilic attack at an unexpected ring position comes from the direct observation of intermediate Meisenheimer complexes in the NMR spectrum. When 2-chloro-3,6-diphenylpyrazine is treated with KNH2 in liquid ammonia, the intermediate (29) was observed directly (Scheme 8). It was postulated that this initially formed complex rearranges to (30) which gives the observed product by elimination of a chloride ion (73RTC708). 

A variety of conjugated dienones are reduced by lithium-ammonia, presumably via dienyl carbanions analogous to the allyl carbanions encountered in enone reductions. Cross-conjugated l,4-dien-3-ones afford 4-en-3-ones as the major reduction products, indicating that the cyclohexadienyl carbanion (55) protonates largely at C-1. Some protonation at C-5 does occur as shown by examination of the NMR spectrum of the crude reduction product derived from the 17-ethylene ketal of androsta-l,4-diene-3,17-dione. The 17-ethylene ketal of androst-4-ene-3,17-dione is formed in 75%... 

The tetramethylammonium salt [Me4N][NSO] is obtained by cation exchange between M[NSO] (M = Rb, Cs) and tetramethylammonium chloride in liquid ammonia. An X-ray structural determination reveals approximately equal bond lengths of 1.43 and 1.44 A for the S-N and S-O bonds, respectively, and a bond angle characteristic bands in the IR spectrum at ca. 1270-1280, 985-1000 and 505-530 cm , corresponding to o(S-N), o(S-O) and (5(NSO), respectively. Ab initio molecular orbital calculations, including a correlation energy correction, indicate that the [NSO] anion is more stable than the isomer [SNO] by at least 9.1 kcal mol . ... 

Aminopyrroles are usually formulated as such because they are quite strong bases and do not easily lose ammonia by hydrolysis. In agreement with the amino formulation, the infrared spectrum of the a-aminopyrrole 93 (R = H) contains a v NHg doublet and a band near 1660 cm" corresponding to the NH2 deformation frequency, and the infrared spectrum of the acetamino derivative is in agreement with the structure 93 (R Ac). However, a stable imino compound, probably with structure 94, has been isolated. ... 

The giant planets possess low surface temperatures and have atmospheres that extend several thousand miles. The markings on Jupiter, the largest planet, consist of cloud formations composed of methane containing a small amount of ammonia. The atmosphere of Jupiter absorbs the extreme red and infrared portions of the spectrum. These absorptions correspond to the absorption spectra of ammonia and methane, suggesting the presence of these gases in Jupiter s... 

Lightman A., Ben-Reuven A. Line mixing by collisions in the far-infrared spectrum of ammonia, J. Chem. Phys. 50, 351-3 (1969) Cross relaxation in the rotational inversion doublets of ammonia in the far infrared, J. Quant. Spectrosc. Radiat. Transfer 12, 449-54 (1972). 

The positive-ion Cl spectrum, using ammonia as a reagent gas, of an analyte containing carbon, hydrogen, oxygen and two nitrogen atoms, has a molecular species at m/z 222. What is the molecular weight of the compound Involved ... 

Figure 9.19. Secondary-ion mass spectrum of a promoted Fe-Sb oxide catalyst used for the selective oxidation of propylene and ammonia to acrylonitrile, showing the presence of Si, Cu, and Mo along with traces of alkali in the catalyst. [Reproduced from J.W. Niemantsverdriet, Spectres-200 gpy jfj Catalysis, 2" Edn.

A. Preparation.—Halogen displacement reactions have been used to prepare a number of new aminofluorophosphines. Aminodifluorophos-phine (1) has been prepared for the first time, from either bromodifluoro-phosphine or chlorodifluorophosphine, and ammonia. Studies of its n.m.r. spectrum have been made (see Chapter 11). The related NN-difluoroaminodifluorophosphine (2) has been prepared, from difluoroiodo-phosphine, and found to be explosive. Two syntheses of A-alkyl-amino-difluorophosphines have been reported, one of which was complicated by the subsequent formation of the phosphorane (3) and the bis-(A-alkylamino)fluorophosphine (4). 

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. ... 

Figure 3.52. TPD. spectrum of ammonia desorbing from H-ZSM-5 (Van Bekkum etal, 1991).

Simultaneously with the STM studies, Kulkarni et al,14 in Cardiff studied by XPS and HREELS the interaction of ammonia with Ni(l 10)-O and Ni(100)-0 surfaces. There was evidence in the N(ls) spectra for more than one nitrogen state present including N(a), but differentiating between NH(a) and NH2(a) was not possible. The intensity in the N(ls) spectrum region was broad over the range 397-400 eV. As the oxygen coverage increased to >0.3, the oxide O2 component became more prominent and the activity for ammonia oxidation decreased, as was observed by STM. Similar conclusions were reached for water interaction with the Ni(110)-O system.15... 

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