Applied to compounds

However, the term saturated is often applied to compounds containing double or triple bonds which do not easily undergo addition reactions. Thus ethanoic acid is termed a saturated carboxylic acid and acetonitrile a saturated nitrile, whereas a Schiff base is considered to be unsaturated. 

Conceptually the most simple syntheses of complex molecules involve the joining of structural units in which all functional groups and all asymmetric centres are preformed. This technique can usually only be applied to compounds in which these units are connected by —C—X— bonds rather than C—C. It is illustrated here by the standard syntheses of oligonucleotides, peptides, and polydentate macrocyclic ligands. 

Aliphatic (Section 2 1) Term applied to compounds that do not contain benzene or benzene like rings as structural units (Historically aliphatic was used to descnbe compounds de rived from fats and oils )... 

We are most often concerned with solutions which are dilute with respect to polymer. This means that nj Vj polymer molecule is so much greater than that of the solvent, the disparity in the number of moles is even more extreme than for the same approximation applied to compounds of comparably sized molecules. Since the approximation Xj = n2/(ni -I- n2) = nj/nj apphes to dilute solutions, we can write... 

The trivial name penem has been applied to compounds possessing the ring structure (88). Because of their interesting antibacterial properties, derivatives of this ring system have been extensively investigated since about 1976. The following describes some of the... 

Another limitation with the HI approach is that Uie assumption of dose additivity is most properly applied to compounds iliat induce die same effect by die same mechanism of action. Consequendy, application of die liazard index equation to a number of compounds diat are not expected to induce die same t) pc of effects or that do not act by the same ineclianism could overestimate die potential for effects, aldiough such an approach is appropriate at a screening lc cl. This possibility is generally not of concern if only one or two substances are responsible for driving the HI above unity. 

In the second method, which can be applied to compounds with an optically active center near the potentially tautomeric portion of the molecule, the effect of the isomerization on the optical activity is measured. In favorable cases both the rate of racemization and the equilibrium position can be determined. This method has been used extensively to study the isomerization of sugars and their derivatives (cf. reference 75). It has not been used much to study heteroaromatic compounds, although the very fact that certain compounds have been obtained optically active determines their tautomeric form. For example, oxazol-5-ones have thus been shown to exist in the CH form (see Volume 2, Section II,D,1, of article IV by Katritzky and Lagowski). 

More serious limitations and precautions apply to compounds in which not all three R, R, and R" groups are aromatic. Autocondensation of benzylideneacetone (111) yields an unstable chloroferrate which may be 113 or 115, according to whether a Michael addition to 112 or a crotonic condensation to 114 is first involved. Since compound 113 could readily be prepared from 2,6-dimethyl-4-phenylpyrylium and benzaldehyde, the structure of the reaction product should be easily soluble. Another equivocal product is formed from two moles of benzylideneacetone, but a definite structure (116) results from chalcone and benzylideneacetone. ... 

Molar mass is important when we need to know the number of atoms in a sample. It would be impossible to count out 6 X ID23 atoms of an element, but it is very easy to measure out a mass equal to the molar mass of the element in grams. Each of the samples shown in Fig. E.2 was obtained in this way each sample contains the same number of atoms of the element (6.022 X 1023), but the masses vary because the masses of the atoms are different (Fig. E.4). The same rule applies to compounds. Flence, if we measure out 58.44 g of sodium chloride, we obtain a sample that contains 1.000 mol NaCl formula units (Fig. E.5). 

It follows that aromaticity can be determined from an NMR spectrum. If the protons attached to the ring are shifted downfield from the normal alkene region, we can conclude that the molecule is diatropic, and hence aromatic. In addition, if the compound has protons above or within the ring (we shall see an example of the latter on p. 69), then if the compound is diatropic, these will be shifted upfield. One drawback to this method is that it cannot be applied to compounds that have no protons in either category, for example, the dianion of squaiic acid (p. 69). Unfortunately, NMR is of no help here, since these spectra do not show ring currents. ... 

The reaction has also been applied to compounds with other leaving groups. Diazo ketones, diazo esters, diazo nitriles, and diazo aldehydes react with trialkylboranes in a similar manner, for example. 

APCl is best applied to compounds with low to moderately high polarities. 

Optimization techniques can provide effective ways of sampling large search spaces, and hence several such methods have been applied to compound selec-... 

Recalcitrance is a valuable concept (Alexander 1975) that has been applied to compounds that have not been demonstrably degraded under the conditions used for their... 

The above rules only apply to compounds that undergo passive membrane transport... 

A term applied to compounding ingredients, mainly antioxidants, which inhibit premature degradation of elastomers. 

Applied to compounding ingredients which do not cause a colour change either in the compounds in which they are incorporated or in... 

The same analysis can be applied to compounds with a more complex formula. For example, the oxide LaCoCL, which adopts the cubic perovskite structure, usually shows a large positive Seebeck coefficient, of the order of +700 jjlV K-1, when prepared in air (Hebert et al., 2007). This indicates that there are holes present in the material. The La ions have a fixed valence, La3+, hence the presence of holes must be associated with the transition-metal ion present. Previous discussion suggests that LaCo03 has become slightly oxidized to LaCoCL+j, and contains a population of Co4+ ions (Co3+ + h or Coc0)- Each added oxygen ion will generate two holes, equivalent to two Co4+ ... 

The resistance to oxygen transfer across the air-water interface mainly exists in the water film. Therefore, Equation (4.22) should only be applied to compounds that are comparable to oxygen, i.e., according to Liss and Slater (1974), those that have an HA value greater than -250 atm (mole fraction)-1. 

The deketalization-retroaldol-aldol procedure was applied to compound (100). Acid catalyzed deketalization, followed by the retroaldol-aldol process afforded (101), which could be transformed to the diterpene trachylobane (102)31>. 

The prefix (RS) is used to denote a racemic modification. For example, (RS)-Sec butyl chloride. The symbols R and S are applied to compounds whose absolute stereochemistry has been determined. However, while applying the nomenclature to projection formulae of compounds containing several asymmetric centres Cahn, Ingold. Pielog procedures are supplemented by the following conversion rule. 

The quasi-racemate method is most interesting in the sense that it may be applied to compounds that can not be correlated by direct chemical reactions. 

Ion-pair liquid chromatography can be applied to compounds separated by ion-exchange liquid chromatography, and mixtures of ionic and non-ionic compounds are easily separated. The latter separation is difficult by ion-exchange liquid chromatography. Anions can be separated by reversed-phase ion-pair liquid chromatography (Figure 4.18). 

The experimental criteria should be applied to compounds progressed from the lead identification to the lead optimization stage. 

More examples of palladium-catalyzed reactions applied to compounds prepared from the chloroester 1-Me are shown in Scheme 74. 

A peptide is any compound produced by amide formation between a carboxyl group of one amino acid and an amino group of another. The amide bonds in peptides are called peptide bonds. The word peptide is usually applied to compounds whose amide bonds (sometimes called eupeptide bonds) are formed between C-1 of one amino acid and N-2 of another, but it includes compounds with residues linked by other amide bonds (sometimes called isopeptide bonds). Peptides with fewer than about 10-20 residues may also be called oligopeptides those with more residues are called polypeptides. Polypeptides of specific sequence of more than about 50 residues are usually known as proteins, but authors differ greatly on where they start to apply this term. 

The positional parameters given for GdFeOs (70) may also be applied to compounds NaMeFs and show that the Me-ions retain their special positions. They occupy the corners of a smaller, monomolecular pseudocell that is slightly monoclinicly distorted. By displacements of the fluoride ions the MeFe-octahedra are also somewhat distorted. Above all the three-dimensional linking of octahedra is not linear any more but exhibits angles of about 150° at the fluorine atoms. 

The excellent ability of late transition metal complexes to activate alkynes to nucleophilic attack has made them effective catalysts in hydroamination reactions. The gold(l)-catalyzed cyclizations of trichloroacetimidates 438, derived from homopropargyl alcohols, furnished 2-(trichloromethyl)-5,6-dihydro-4f/-l,3-oxazines 439 under exceptionally mild conditions (Equation 48). This method was successfully applied to compounds possessing aliphatic and aromatic groups R. With R = Ph, cyclization resulted in formation of 439 with complete (Z)-stereoselectivity <2006OL3537>. 

Berzelius method of assigning letters to represent elements was also applied to compounds. Berzelius used superscripts to denote the number of atoms in a compound. Thus, water would be O and carbon dioxide CO. Later these superscripts were changed to the current practice of designating the number of atoms using subscripts. The absence of a subscript implies the subscript one. Using symbols we can write the chemical formula for ammonia ... 

---