FORMULAE INDEX

Several relationships aid in deducing the empirical formula of the parent ion (and also molecular fragments). From the empirical formula hypothetical molecular structures can be proposed, using the entries in the formula indices of Beilstein and Chemical Abstracts. 

Unless otherwise stated, the term g per liter signifies grams of the formula indicated dissolved in water and made up to a liter of solution. 

Brutto-formel, /. a formula indicating merely the number of atoms of each kind, and not their mode of union, an empirical molecular formula (e.g., CsHa). -gewicht, n. gross weight, -wert, m. gross value. 

Using the terminology of Sec. 5 of the Introduction we can state the number of those structurally isomeric homologues of a given basic compound which contain n carbon atoms more than the basic compound is asymptotically proportional to the number of the structurally isomeric The formula indicates, furthermore, how the... 

A simplification in the graphical interpretation of acyclic chemical compounds is possible in the case of saturated acyclic hydrocarbons, once known as paraffins but now more usually called "alkanes". These have the general formula indicating the... 

Quite often, molecules have the same chemical formula but differ in their structures. For example, two compounds have the chemical formula C2 Hg O (Figure 3-2b and c). Dimethyl ether has a C—O—C linkage, while ethanol contains C—O—H. To distinguish between these two different substances, chemists write the formula of dimethyl ether as CH3 OCH3 and the formula of ethanol as CH3 CH2 OH. The first formula indicates that the molecule has two CH3 units linked to an oxygen atom. The second formula tells us that there is a C2 H5 unit attached to an OH group. Molecules that have the same molecular formula but different arrangements of atoms are called isomers. 

Although the chemical formulas indicate that ribose is a pentose and fructose is a hexose, the ring portions of the structures are the same size. Proceeding clockwise around the rings from the oxygen atom, we see that the structures differ at the first two positions. In the first position, ribose has a carbon atom bonded to —H and —OH, while)S-fructose has a carbon bonded to —OH and — CH2 OH. In the second position the molecules have the same two bonds but in different orientations. The OH group points up in y6-fructose and down in ribose. The two molecules have the same structures at the other positions. 

Hydroxygelsemicine (7, C20H26N2O5) was isolated from G. sempervirens. Its molecular formula indicated the presence of an extra oxygen atom in gelsemicine (C20H26N2O4), most likely in the form of a hydroxy group. The... 

An empirical formula indicates the simplest grouping of atoms that has the same ratio of elements as are present in the compound. The molecular formula indicates the... 

The standard deviation can be used as a measure of risk. For example, if we pool the risk of random demands by several customers in one warehouse, the above formula indicates that the risk increases slower than the mean demand. It is therefore generally a good idea to pool risks. 

These data, together with the molecular formula, indicated that the oxygen must be present as an ether bridge. If the doublet at 77.7 ppm is due to an aminomethine, the second carbon of the ether bridge should give rise to the singlet at 80.1 ppm. The only biosynthetically reasonable structures that could explain this spectral behavior are 2,14-oxidopseudoaspidospermidine (306) (without stereochemistry) or the new structure 173. Structure 306 was easily... 

In Chapter 2, we saw molecular and empirical formulas. Recall that the molecular formula indicates the kind and actual number of atoms present. The empirical formula simply shows the kind of atoms present and their lowest whole number ratio. In this chapter, structural formulas are important. The Lewis formula of a compound is an example of a structural formula. A structural formula shows the number and type of atoms present, as well as the bonding pattern. The bonding pattern shows which atoms bond to each other. It usually... 

As will be seen, the primary product from o-cresol cannot reconstitute the aromatic ring because of the CH3-group. Hence only NaCl is eliminated. The other two chlorine atoms are not hydrolytically removed and a quinol-like substance is formed, as the formula indicates ... 

The empirical formula indicates which elements are present and the lowest whole-number ratio. 

An empirical formula indicates a set A of n atoms which is contained in a given molecule, or ensemble of molecules (EM). Thus an EM(A)... 

Pseudopterosin X (1) was isolated as a yellow colored gum. The UV spectrum of 1 showed maximum absorption at 280 nm due to the presence of a highly substituted benzene chromophore [10], Its IR spectmm displayed intense absorption bands at 3,470 (OH), 2,904 (CH), 1,705 (C = O), 1,595 (C = C) and 1,100 (C-0) cm . The high-resolution electron-impact mass spectmm (HREIMS) of 1 showed M+ at m/z 474.2622, and this mass provided molecular formula indicating the presence of nine double bond equivalents in 1. The C-NMR chemical shift assignments of 1 are shown around stracture 1. On the basis of the detailed NMR studies and comparison with the reported pseudopterosins in the literature and L-xylose [3-5], stmcture 1 was proposed for this new natural product. 

One of the most important electrolytic processes is the extraction of aluminum from an ore called bauxite. This ore is mainly composed of hydrated aluminum oxide, AI2O3 XH2O. (The x in the formula indicates that the number of water molecules per formula unit is variable.) In industry, the scale of production of metals is huge. The electrolytic production of aluminum is over two million tonnes per year in Canada alone. As you know from Faraday s law, the amount of a metal produced by electrolysis is directly proportional to the quantity of electricity used. Therefore, the industrial extraction of aluminum and other metals by electrolysis requires vast quantities of electricity. The availability and cost of electricity greatly influence the location of industrial plants. 

The previous formula indicates that the radiative lifetime tq (and hence the radiative rate A) can be determined from luminescence decay-time measurements if the quantum efficiency rj is measured by an independent experiment. Methods devoted to the measurement of quantum efficiencies are given in Section 5.7. 

The conditions leading to the formation of F indicate a disubstituted aromatic ring. In addition, the reaction conditions and formula indicate thatFis a diccirboxylic acid. Disubstitution may be ortho, meta, or pcira. 

In general, the tip DOS does not resemble that of a free-electron metal. To have meaningful STS measurements, the tip DOS must be determined independently. A well-established experimental method for determining the energy spectmm a sharp metal tip is field emission spectroscopy (FES), which was described in Section 4.4. For free-electron metal tips, the FES is described by the Young formula, Eq. (4.20). A deviation from the Young formula indicates a deviation from a free-electron metal behavior. 

The Structure of Polycyanometalates metal hexacyanometalates. The chemical formulae indicate the... 

Benzene was discovered in 1825 by Michael Faraday who identified it from a liquid residue of heated whale oil. Faraday called the compound bicarburet of hydrogen and its name was later changed to benzin by Eilhardt Mitscherlich (1794—1863) who isolated the compound from benzoin. Benzene s formula indicates it is highly unsaturated. This would suggest benzene... 

No further mention of explosive props of iodonitromethanes were found in the CA Formula Indices 1920-1971... 

The formulas in Sections II-VI usually represent, for simplicity, molecules belonging to the D configurational series, although they actually refer to racemic mixtures. Section VII deals with the preparation of optically active sugars in this Section, the formulas indicate the true configuration of the molecules. 

The best known of these compounds is potassium cobalti-nitrite, [Co(N02)6]K3.1 This salt was originally regarded as a double salt of cobaltic nitrite with potassium nitrite, and represented by the formula Co(NQ2)3.3KNOa. Such a formula, however, does not represent the reactions of the substance, as the nitrite radicle is held firmly, and nitrous aeid is not liberated when the compound is treated with cold dilute acids, as it would be if it were a double salt as the formula indicates. Molecular conductivity measurements also indicate that it is a complex salt comparable with the metal-ammines. Many compounds of cobalt of this type are known. They may be regarded as the salts of the complex acid hexanitrito-cobaltic acid, [Co (N02)6]H3. 

Herbs that tonify the blood form the main part of this formula, indicating the close relationship between the Yin and blood of the Liver. This also suggests that this formula is particularly suitable to be applied at the initial and second stages of Liver-Yin deficiency, which manifest as dizziness, blurred vision or decreased vision, numbness and tingling of the limbs, and cramp of the muscles. A red, dry tongue and a wiry, thready pulse are often observed in this condition. 

The dot in the formula indicates that 3 moles of water are combined with I mole of... 

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