Deuterated ammonias

In the present work low temperature adsoi ption of fluoroform and CO, were used to characterize surface basicity of silica, both pure and exposed to bases. It was found that adsorption of deuterated ammonia results in appearance of a new CH stretching vibration band of adsorbed CHF, with the position typical of strong basic sites, absent on the surface of pure silica. Low-frequency shift of mode of adsorbed CO, supports the conclusion about such basicity induced by the presence of H-bonded bases. 

Figure 11. Average ion kinetic energies as a function of cluster size for ammonia clusters and deuterated ammonia clusters resulting from Coulomb explosion of clusters. The average kinetic energies are obtained from the splittings in the cluster ion time-of-flight peaks see Figure 10. Taken with permission from ref. 90.

Philippaerts92 has shown, using deuterated ammonia, that following reaction occurs in a mordenite zeolite ... 

We have combined MD simulations and quantum chemical calculations of the EFG tensor to obtain accurate liquid state values for QCC of and in deuterated ammonia [44]. The experimental gas phase value of QCC( N) is -4.09 MHz [b] while the corresponding reported solid state value is -3.43 MHz at 77K. A difference of more than 16 %. Molecular motion, of course, will affect the QCC values. Similar values for QCC( H) are 290.6 kHz and 208 kHz, respectively. 

The fragmentation of protonated triazines was investigated in detail by Nelieu et al. [37], using a triple-quadrapole instmment and deuterated ammonia. The MS-MS product-ion mass spectmm of protonated atrazine is shown in Figure 7.2. The fragmentation is explained in Table 7.3. Stepwise fragmentation of triazines can be observed in multistage MS-MS in an ion-trap, as demonstrated for propazine [38], and for atrazine, simazine, and terbutylazine [25]. 

If samples contain many salts, these are diluted with water and applied to a column containing 0.5 ml of Q-Sepharose (adjusted to the chloride form). After washing twice with 4ml of 2.5mmoll hydrochloric acid, inositol phosphates are eluted with 2 X 2.5 ml of 0.6 mol 1 hydrochloric acid. The eluate is frozen and freeze-dried to remove the acid. Dried sample is dissolved in 2.2ml of 5mmoll sodium acetate, pH 5.0. For subsequent nuclear magnetic resonance (NMR) and NMR spectra, dried extracts containing polyols are dissolved in 0.7 ml of deuterium oxide (99.996% deuteration) and the pH value adjusted to either 6.0 or 9.0 by adding deute-rated formic acid and deuterated ammonia. 

Chemical ionization MS, with various deuterated reagent gases, has been used to probe the number and nature of active hydrogens in a molecule. For example, based on the mass shifts of the protonated ions that are observed when switching from ammonia (NH3) to deuterated ammonia (ND3), the number of active hydrogens in morphine and several other drugs have been demonstrated. 

Benedict WS, Plyler EK (1957) Vibrationrotation bands of ammonia II. The molecular dimensions and harmonic frequencies of ammonia and deuterated ammonia. Can J Phys 35 1235-1241... 

Kevan and co-workers investigated the framework substitution and local environment of the nickel ions in several NiAPSO-n molecular sieves in = 5, 11, 34, 41) (204) by ESR and ESEM spectroscopy. In all the systems, the Ni(II) ions are incorporated into the framework positions and various Ni(I) species are formed by reduction and adsorbate interaction. Deuterated ammonia adsorption... 

Spectroscopic studies of isotopically substituted molecules often involve special syntheses which must be designed so as to make the best possible use of the isotope to be incorporated. For example, deuterated ammonia, ND3, would not be prepared by exchange between NH3 and D2O since a large proportion of the deuterium is wasted in conversion to HOD. A better method is to react D2O with Mg3N2 (eq. 4.8). 

The observed enhancements of deuterated ammonia, NHjD, and deuterated water, HDO, cannot be produced by gas phase chemistry at the high temperatures deduced for the hot core. In addition, the abundances cannot be reproduced by the "freezing" of cold phase peak abundances discussed in section 3. However, the enhanced abundances of deuterated species may be explained by including reactions with deuterium atoms on grain surfaces. 

In an effort to verify this model, this reaction was compared to that using deuterium to produce deuterated ammonia [16] ... 

A stabilization of NH5 by solvation was suggested in a study of reactions following electron impact ionization of neat cluster beams of ammonia and of heteroclusters of ammonia-benzene. Peaks in the mass spectrum were assigned to [NH5(NH3)n] adducts, where n>4. Analogous results were obtained with deuterated ammonia [3]. An ab initio SCF MO study on ammoniated NH5 adducts [2] indicated that the species observed in the mass spectrum [3] is possibly ammoniated N2H8 ( = NH4NH4). 

In one series of experiments performed in the Department, packets of Stark-decelerated deuterated ammonia ( NDs) molecules with a forward velocity of about 125m/s were tangentially injected into the synchrotron. At its entry, a packet is several millimeters long and consists of about a million molecules. All these molecules are in the upper inversion doublet component of a single rotational level, the ground-state level of para-ammonia, hosted by the vibrational and... 

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