The Diversity of Organic Compounds

The diversity of organic compounds presents some challenges. It is not uncommon for several different organic compounds to have the same molecular formula, for example, but to display different properties depending on exactly how the atoms are arranged into molecules. (Different compounds with the same molecular formula are called isomers) So organic chemists frequently must depict... 

The diversity of organic compounds results from the uniqueness of carbon s structure and bonding. Carbon s electronic structure allows it to bind to itself to form chains and rings, to bind covalently to other elements, and to bind to itself and other elements in different arrangements. 

What are three characteristics of carbon that contribute to the diversity of organic compounds ... 

The largest part of the subject is the nomenclature of organic compounds, simply because there are so many of them, and of such diverse nature. The types of compounds and stmctures differ considerably among organic, inorganic, and biochemical substances, and each of their respective nomenclatures has developed somewhat differendy, although not independendy. Macromolecular nomenclature and pharmaceutical nomenclature have practical requirements of their own. It is therefore appropriate to treat each of these several areas separately. 

In this review, data have been presented to illustrate the diversity of organisms living in the sea and the plethora of chemical compounds that have been discovered from them. Since the late 1970s, there has been a veritable explosion of activity and many new marine metabolites have been isolated and identified. Therefore, the present review will cover only recent development in this area. The information was obtained from a review of the scientific literature, and the sources are referenced at the end of the chapter. Bioactive compounds found in marine environments include... 

SIMS has become a diverse tool in the study of many different substances other than metals and semiconductors. This part of the paper discusses the secondary ion emission of molecular and polyatomic ions from the surfaces of organic compounds including polymers and biomolecules. 

Chemists refer to salicin, ASA, and more than ten million other chemicals like them as organic compounds. An organic compound is a molecular compound of carbon. Despite the tremendous diversity of organic compounds, nearly all of them share something in common. They are structured from a backbone that consists of just two kinds of atoms carbon and hydrogen. 

Solubility is commonly defined as the concentration of dissolved solute in a solvent in equilibrium with undissolved solute at a specified temperature and pressure. For a deeper and more detailed understanding of the diverse rules determining the solubility of organic compounds in various solvents, see references [312-316],... 

Extraction techniques are universal, standardized, and commonly applied sample preparation methods (see for example [1 ]). Development of extraction methodology in the past 20 years has been eventful and impressive. Universalism of these techniques is associated with applicability to analyses of a great diversity of organic compounds (including DNA and RNA) and elements and their speciation forms, which are present in different sample matrices both in trace and macro quantities. 

There is yet a third and independent complication which might seriously affect the efficiency of the transformation of organic compounds. In the majority of organic transformations, fairly different products can be obtained from the same set of starting materials. In fact, the diversity in available reaction pathways is a source of major problems and uncertainties arising in the course of planning an organic synthesis. 

Development of quantitative relationships to predict the fate and effects of aquatic contaminants from easily measured properties is important for threo reasons (1) the variety of organic compounds potentially present in aquatic systems (2) the number and complexity of physical and chemical processes involved in contaminant transport and transformation, and (3) the diversity of organisms that may be affected by contaminants or involved in their biodegradation. Most attention has focused on organic compounds, but some... 

Figure 15.2 The chemical diversity of organic compounds. Different arrangements of chains, branches, rings, and heteroatoms give rise to many structures. There are 23 different compounds possi-bie from just four C atoms joined by singie bonds, one O atom, and the necessary H atoms.

The structural complexity of organic compounds arises from carbon s small size, intermediate EN, four valence electrons, ability to form multiple bonds, and absence of d orbitals in the valence level. These factors lead to chains, branches, and rings of C atoms joined by strong, chemically resistant bonds that point in as many as four directions from each C. The chemical diversity of organic compounds arises from carbon s ability to bond to many other elements, including O and N, which creates polar bonds and greater reactivity. These factors lead to compounds that contain functional groups, specific portions of molecules that react in characteristic ways. 

The labeling of organic compounds with stable or radioactive isotopes now constitutes an extremely important area of preparative chemistry. The number of publications in that field has grown to such an extent that it is almost impossible to find them all. This alone indicates the ever growing importance of labeled compounds in diverse branches of science moreover, the work reactivates the experimental demands on preparative chemists because an extraordinarily large number of compounds of different isotopic composition are open to synthesis. For instance, even such a relatively simple molecule as propane can afford no less than twenty-nine different deuterium-labeled compounds with eight different molecular formulae. 

In this context, it is important to recognize that the biodegradation of organic compounds in the environment is very complex. Whitman et al. [37] have estimated that on the order of 10 bacteria exist on earth. This represents a mass comparable to that of all the green plants on earth. Studies of extracted environmental DNA also show enormous species diversity in bacteria [38]. Perhaps 10 bacterial species were demonstrated in 1 g of typical soil. With such enormity and complexity, how can one reasonably improve on current biodegradation prediction ... 

Speciation analysis can involve the measurement of discrete chemical compounds (e.g., methylmercury chloride, tributyltin oxide, arsenobetaine), or in some cases different oxidation states or the identification of common classes of compounds that might be operationally defined on the basis of their reactivity, size, or some other physicochemical property. Speciation analysis methods are generally more complex than procedures used for measuring total metal concentrations. This review focuses primarily on trace elements the diverse speciation of carbon (i.e., organic chemistry) and the analysis of organic compounds are not covered. 

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