Organic chemistry importance

For example, Weissermel, K. Arpe, H.-J. Industrial Organic Chemistry Important Raw Materials and Intermediates Verlag Chemie New York, NY, 1978, pp. 143-144. 

As a special development in recent years, SEMs have been designed which no longer necessitate high vacuum (enviromnental SEM, ESEM variable pressure SEM, VPSEM). This development is important for the imaging of samples with a residual vapour pressure, such as aqueous biological or medical samples, but also samples in materials science (wet rock) or organic chemistry (polymers). 

Hydrazine and its alkylated derivatives are used as rocket fuels in organic chemistry, substituted phenylhydrazines are important in the characterisation of sugars and other compounds, for example aldehydes and ketones containing the carbonyl group C=0. 

The 20th century brought important advances in the field of organic chemistry. In the first decades of the century, the syntheses of inaeasingly complex molecules were accomplished. Some notable compounds synthesized during that time were a-terpinol (WH. Perkin, 1904), camphor (G. Komppa, 1903), and tropinone (R. Robinson, 1917 Figure 10.3-28). 

The three most important abstracting journals for organic chemistry are ... 

Iodine compounds are important in organic chemistry and very useful in medicine. Iodides, and thyroxine which contains iodine, are used internally in medicine, and as a solution of KI and iodine in alcohol is used for external wounds. Potassium iodide finds use in photography. The deep blue color with starch solution is characteristic of the free element. 

Nitration is important for two reasons firstly, because it is the most general process for the preparation of aromatic nitro compounds secondly, because of the part which it has played in the development of theoretical organic chemistry. It is of interest because of its own characteristics as an electrophilic substitution. 

You are studying organic chemistry at a time of its greatest influence on our daily lives at a time when it can be considered a mature science when the challenging ques tions to which this knowledge can be applied have never been more important... 

One more hybridization scheme is important m organic chemistry It is called sp hybridization and applies when carbon is directly bonded to two atoms as m acetylene The structure of acetylene is shown m Figure 2 18 along with its bond distances and bond angles Its most prominent feature is its linear geometry... 

SnI and Sn2 are among the most fundamental and important mechanisms m organic chemistry We will have much more to say about them m Chapter 8... 

Alkenes are hydrocarbons that contain a carbon-carbon double bond A carbon-carbon double bond is both an important structural unit and an important func tional group m organic chemistry The shape of an organic molecule is influenced by the presence of this bond and the double bond is the site of most of the chemical reactions that alkenes undergo Some representative alkenes include isobutylene (an industrial chemical) a pmene (a fragrant liquid obtained from pine trees) md fame sene (a naturally occurring alkene with three double bonds)... 

Section 8 1 Nucleophilic substitution is an important reaction type m synthetic organic chemistry because it is one of the mam methods for functional group transformations Examples of synthetically useful nucleophilic sub stitutions were given m Table 8 1 It is a good idea to return to that table and review its entries now that the details of nucleophilic substitution have been covered... 

The next several chapters deal with the chemistry of various oxygen containing func tional groups The interplay of these important classes of compounds—alcohols ethers aldehydes ketones carboxylic acids and derivatives of carboxylic acids— IS fundamental to organic chemistry and biochemistry... 

Some esters of inorganic acids such as dimethyl sulfate are used as reagents m syn thetic organic chemistry Certain naturally occurring alkyl phosphates play an important role m biological processes... 

The present chapter extends our study of carbanions to the enolate ions derived from esters Ester enolates are important reagents m synthetic organic chemistry The stabilized enolates derived from p keto esters are particularly useful... 

Resonance, polarity, and steric considerations are all believed to play an important role in copolymerization chemistry, just as in other areas of organic chemistry. Things are obviously simphfied if only one of these is considered but it must be remembered that doing this necessarily reveals only one facet of the problem. Nevertheless, there are times, particularly before launching an experimental investigation of a new system, when some guidelines are very useful. The following example illustrates this point. 

In organic chemistry there are many important molecules that contain two or more groups each of which, in isolation, would be chiral. A simple example is that of 2,3-difluorobutane, shown in Figure 4.9. The molecule can be regarded as a substituted ethane and we assume that, as in ethane itself, the stable sttucture is one in which one CFIFCFI3 group is staggered relative to the other. 

In Chapter 4, on molecular symmetry, 1 have added two new sections. One of these concerns the relationship between symmetry and chirality, which is of great importance in synthetic organic chemistry. The other relates to the connection between the symmetry of a molecule and whether it has a permanent dipole moment. 

Uses. Magnesium iodide is used in the deoxygenation of oxiranes into olefins and iodine. This step is important to organic chemistry because it helps in the stmcture elucidation of complex organic molecules (110). Eor example. 

The derivatives of the aminophenols have important uses both in the photographic and the pharmaceutical industries. They are also extensively employed as precursors and intermediates in the synthesis of more compHcated molecules, especially those used in the staining and dye industry. All of the major classes of dyes have representatives that incorporate substituted aminophenols these compounds produced commercially as dye intermediates have been reviewed (157). Details of the more commonly encountered derivatives of the aminophenols can be found in standard organic chemistry texts (25,158). A few examples, which have specific uses or are manufactured in large quantities, are discussed in detail in the following (see Table 6). 

Addition of sodium dithionite to formaldehyde yields the sodium salt of hydroxymethanesulfinic acid [79-25-4] H0CH2S02Na, which retains the useful reducing character of the sodium dithionite although somewhat attenuated in reactivity. The most important organic chemistry of sodium dithionite involves its use in reducing dyes, eg, anthraquinone vat dyes, sulfur dyes, and indigo, to their soluble leuco forms (see Dyes, anthraquinone). Dithionite can reduce various chromophores that are not reduced by sulfite. Dithionite can be used for the reduction of aldehydes and ketones to alcohols (348). Quantitative studies have been made of the reduction potential of dithionite as a function of pH and the concentration of other salts (349,350). 

Because of the importance of cellulose and the difficulty in unraveling its secrets, several societies (CeUucon, American Chemical Society, and TAPPI) are dedicated to cellulose, lignin, and related molecules, as is at least one journal that is abstracted by Chemicaly hstracts (3). The length of the proceedings of the Tenth Cellulose Conference (1638 pages) (4) indicates the vitaUty and interest in this subject, but research results are pubUshed in many other journals as well. There are also several recent books on cellulose (5—9). Reference 10 is a comprehensive review and is recommended especially for the historical review of proof of chemical stmcture, one of the milestones in organic chemistry. 

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