Abbreviations of Compounds

Abbreviations of Compound Classes Discussed in This Chapter... 

Fig. 2. Radiocarbon age of the organic fractions from the sediments of Santa Monica Basin. For explanation of abbreviations of compound class fractions, refer to Fig. 1. Faa fatty acid.

As described above, photocatalysts for the two-electron reduction of CO2 should have both a photosensitizing component for initiating photoinduced one-electron transfer and a catalyst component for activating and introducing two electrons to CO2. The structures and abbreviations of compounds using for the doublecomponent systems, in which the two functions are carried out by two distinct molecules, are shown in Scheme 4. Data relating to their efficacy as a photocatalysts for the reduction of CO2 are summarized in Table 2. 

The abbreviation QSAR stands for quantitative structure-activity relationships. QSPR means quantitative structure-property relationships. As the properties of an organic compound usually cannot be predicted directly from its molecular structure, an indirect approach Is used to overcome this problem. In the first step numerical descriptors encoding information about the molecular structure are calculated for a set of compounds. Secondly, statistical methods and artificial neural network models are used to predict the property or activity of interest, based on these descriptors or a suitable subset. A typical QSAR/QSPR study comprises the following steps structure entry or start from an existing structure database), descriptor calculation, descriptor selection, model building, model validation. 

Since the interaction of the mixture components with the liquid stationary phase plays the key role in the separation process, the nature of the stationary phase is obviously important. Several hundred different liquids useful as stationary phases are known. This means that the analyst has an awesome choice when it comes to selecting a stationary phase for a given separation. It is true, however, that relatively few such liquids are in actual common use. Their composition is frequently not obvious to the analyst because a variety of common abbreviations have come to be popular for the names of some of them. Table 12.3 lists a number of common stationary phases, their abbreviated names, a description of their structures, and the classes of compounds (in terms of polarity) for which each is most useful. 

Writing conventions Check to be sure that you have used voice (mostly passive) and tense (mostly past tense) correctly. Check your formatting of units and numbers, use of abbreviations and acronyms, and capitalization of compounds and vendors. 

In many cases, abbreviation of substitutents could no longer be made without ending up with hardly understandable chemical nomenclature (e.g., complex-O-cyclosubstitution). This problem was already obvious in the publication of Barron and Ibrahim who shifted to illustrations of such complex compounds. Consequently, figures of structures showing characteristic substitution patterns will complete the tabulated information provided here. 

TNT is the abbreviation of the aromatic nitrated aromatic compound 2,4,6-trinitrotoluene. It is a pale-yellow crystalline solid that was first synthesized in 1863 by the German chemist Joseph Wilbrand (1811—1894), but it was not immediately used as an explosive. TNT is made by nitrating toluene using nitric acid, sulfuric acid, and oleum (a mixture of sulfuric acid and S03). Nitration of toluene occurs in stages, with the nitro units added sequentially in a stepwise process as the reaction proceeds. The last nitro unit is accomplished by using oleum (SO, dissolved in sulfuric acid). After nitration, unused acids are recycled, and the product is washed with sodium sulfite and water to remove impurities. 

The present chapter includes commercially available organic chemicals. Most of the organo- phosphorus, boron, silicon, alkali metal compounds and metal ion salts are in Chapter 4. Naturally occurring commercially available organic compounds of use in biochemistry, molecular biology and biology are included in Chapter 5. Abbreviations of words and some journal names are listed in Chapter 1, pages 1 and 2. 

The chromatographic conditions [analytes, samples, columns, mobile phases, detection, and limits of detection (LODs)] are summarized in the tables following each section. The names of compounds are abbreviated, and the abbreviations are explained in the first paragraphs of each section other abbreviations are listed at the end of this chapter. 

Trimethoxysilyl)propyloctadecyldimethylammonium chloride (SiQAC) was obtained from Dow Coming Corporation, Midland, MI, as a 40% solution in methanol. A suitable aliquot of this solution was rotary-evaporated to remove most of the methanol and then diluted to 10 ml with an appropriate solvent. An infrared spectrum was recorded immediately after this procedure to obtain the initial methanol concentration. It was observed that complete evaporation of the methanol to solid SiQAC results in hydrolysis of the methoxy groups and condensation of the silanol groups to form siloxane bonds. Scheme 1 shows the structures and abbreviations of all the compounds used in this investigation. 

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