Hydrogen names

Hydrogen names are useful when the connectivity (the positions of attachment of the hydrons) in a hydron-containing compound or ion is unknown or not specified (i.e. when which of two or more tautomers is not specified, or when one does not wish to specify a complex connectivity, such as in network compounds). 

Some of the following examples are discussed in detail below. 

In Example 1, the two hydrons could be located either on two oxygen atoms on the same phosphorus atom or one on each of the phosphorus atoms. Thus, as already indicated, hydrogen names do not necessarily fully specify the structure. 

In the same way, the hydrogen name in Example 9 covers, in principle, two tautomers. This also applies to the common compositional name hydrogen cyanide . The names hydridonitridocarbon (additive nomenclature), methylidyneazane (substitutive nomenclature) and formonitrile (functional organic nomenclature) all specify the tautomer HCN. 

Hydrogen names may also be used for molecular compounds and ions with no tautomerism problems if one wishes to emphasize the conception of the structure as hydrons attached to the anion in question  

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Chemically, all clays are composed of oxides of silicon, aluminum, and hydrogen - namely, silicon dioxide, aluminum trioxide, and water in a weight proportion that can be expressed by the following general formula (see Fig. 50) ... 

Next, we divide the mass of hydrogen in each compound by the smallest mass of hydrogen, namely, 0.0720 g. This gives 3.000 for compound A, 1.000 for compound B and 2.00 for compound C. The ratio of the amounts of hydrogen in the three compounds is 3 (comp A) 1 (comp B) 2 (comp C)... 

In neutral or alkaline solution the conditions are altered so as to favour the immediate precursor of the final product of hydrogenation, namely, phenylhydroxylamine. This compound is obtained from nitrobenzene, suspended in ammonium chloride solution, by reduction with zinc dust. Zinc dust can decompose water with the formation of Zn(0H)2 if a substance is present which takes up the liberated hydrogen. Molecular, i e. ordinary, oxygen is capable of doing this and is thereby converted into hydrogen peroxide (M. Traube) ... 

In a broader sense, the term aldol condensation has sometimes been applied to many so-called aldol-type condensations involving reactions of an aldehyde or ketone with a substance containing a mobile hydrogen, namely... 

It is well known, even from old literature data (ref. 1) that the presence of metal promotors like molybdenum and chromium in Raney-nickel catalysts increases their activity in hydrogenation reactions. Recently Court et al (ref. 2) reported that Mo, Or and Fe-promoted Raney-nickel catalysts are more active for glucose hydrogenation than unpromoted catalysts. However the effects of metal promotors on the catalytic activity after repeated recycling of the catalyst have not been studied so far. Indeed, catalysts used in industrial operation are recycled many times, stability is then an essential criterion for their selection. From a more fundamental standpoint, the various causes of Raney-nickel deactivation have not been established. This work was intended to address two essential questions pertinent to the stability of Raney-nickel in glucose hydrogenation namely what are the respective activity losses experienced by unpromoted or by molybdenum, chromium and iron-promoted catalysts after recycling and what are the causes for their deactivation ... 

Activity measurement 1,3 butadiene hydrogenation was chosen as a probe reaction. The four major products of 1,3 butadiene hydrogenation, namely 1-butene, n-butane, cis- and trans-2-butene were monitored to study the pretreatment effect on the selectivity. Activity measurements were conducted after preheating the catalysts in-situ in various atmospheres without exposure to air. Two pieces of film catalysts were placed in a 0.8 cm ID quartz tube reactor and were pretreated as follows. 

Give an equation for the complete hydrogenation of trilinolein using an excess of hydrogen. Name the product, and predict approximate melting points for the starting material and the product. 

When suspended in water palladium black absorbs even more hydrogen, namely, in one case 1204 times its own volume,3 Under similar conditions it likewise absorbs acetylene slowly when suspended in 60 per cent, alcohol it has a pronounced adsorptive action,4 as also when suspended in an aqueous solution of sodium protalbinate. The absorbed acetylene exhibits an enhanced chemical activity. The curves obtained by plotting the rate of absorption of hydrogen by platinum black are smooth, indicating that only one allotropic form of palladium is present.5... 

The chemical shift of each carbon in a molecule can be predicted accurately by the same type of correlations used for hydrogens, namely, an appropriate base value plus substituent parameters [Eq. (6.5b)]. 

In the present work we investigate a part of the two-loop self-energy correction to the Lamb shift in hydrogen, namely the irredncible part of diagram Fig. 1(a), referred to as the loop-after-loop correction. This contribntion has been the snb-ject of a recent debate in the literature. Analytic calculations of its. Za-expansion coefficients were carried out by Eides and co-workers [1] and Pachucki [2] in order a Za) and by Karshenboim [3] in order A direct numer-... 

Although the applicability is limited to Grignards having no jS-hydrogen, namely MeMgX and PhMgX, nickel-catalyzed carbomagnesations of acetylenes have been documented [Eqs. (29) 84 and (30) 51]. 

In hydrogen names (Section IR-8.4), to enclose the part of the name following the word hydrogen. 

When one or more hydron(s) are attached to an anion at (an) unknown position(s), or at (a) position(s) which one cannot or does not wish to specify, a hydrogen name (see Section IR-8.4) may be used. Such names may also be used for simpler compounds, such as partially dehydronated oxoacids. Certain of these names have accepted abbreviated forms, such as hydrogencarbonate, dihydrogenphosphate, etc. All such accepted abbreviated names are given in Section IR-8.5. 

In addition, Sections IR-8.4 and IR-8.5 deal with a further type of names, denoted here as hydrogen names. These names can be viewed as generalizations of common anion names such as hydrogencarbonate , but they are not necessary for naming completely specified molecular structures and can be regarded as a special topic. 

Sections IR-8.4 and IR-8.5 describe hydrogen names, which are related to additive names and only needed in special cases. 

The strict definition of hydrogen names proposed here is meant to eliminate such confusion by imposing the requirements ... 

Hydrogen names constructed in this way cannot be mistaken for other types of name. 

The only acceptable exceptions to the above format for hydrogen names are the few particular abbreviated anion names listed in Section IR-8.5. 

In a few cases, no confusion can arise, and the distinction between compositional name and hydrogen name is not as important, most notably for the hydrogen halides. Thus, HC1 can equally unambiguously be named hydrogen chloride (compositional name) and hydrogen(chloride) (hydrogen name). 

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