Organic chemistry molecules

In organic chemistry the term is used to describe the conversion of an ester to an acid and an alcohol (saponification), the addition of the elements of water to a molecule, e.g. the conversion of a nitrile to an amide... 

Claverie P 1978 Elaboration of approximate formulas for the interactions between large molecules applications in organic chemistry Intermolecular Interactions From Diatomics to Biopolymers ed B Pullman (New York Wiley) p 69... 

Organic chemistry is characterized by a cornucopia of different chemical structures. This is largely because the atoms of an organic molecule can be arranged in a variety of different bonding situations. 

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). 

Semiempirical calculations have been very successful in the description of organic chemistry, where there are only a few elements used extensively and the molecules are of moderate size. Some semiempirical methods have been devised specifically for the description of inorganic chemistry as well. The following are some of the most commonly used semiempirical methods. 

The bibliography for this chapter is perhaps the most difficult to write. The majority of references in this entire book pertain to organic molecules. The organic references listed here are just a few of the review references pertaining specifically to organic chemistry. This list is incomplete, but attempts to include recent reviews, which will reference earlier work. The listing for other classes of molecules are more complete. 

This qualitative theory still provides the most widely used means for describing reactions in organic chemistry. Two principal modes of electronic interaction in organic molecules are recognised the inductive and mesomeric effects. 

All of the material in this text and most of chemistry generally can be understood on the basis of what physicists call the electromagnetic force Its major principle is that opposite charges attract and like charges repel As you learn organic chemistry a good way to start to connect structure to properties such as chemical reactivity is to find the positive part of one molecule and the neg ative part of another Most of the time these will be the reactive sites... 

So far we have emphasized structure in terms of electron bookkeeping We now turn our attention to molecular geometry and will see how we can begin to connect the three dimensional shape of a molecule to its Lewis formula Table 1 6 lists some simple com pounds illustrating the geometries that will be seen most often m our study of organic chemistry... 

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)... 

In organic chemistry chirality most often occurs m molecules that contain a car bon that is attached to four different groups An example is bromochlorofluoromethane (BrClFCH)... 

In computational chemistry it can be very useful to have a generic model that you can apply to any situation. Even if less accurate, such a computational tool is very useful for comparing results between molecules and certainly lowers the level of pain in using a model from one that almost always fails. The MM+ force field is meant to apply to general organic chemistry more than the other force fields of HyperChem, which really focus on proteins and nucleic acids. HyperChem includes a default scheme such that when MM+ fails to find a force constant (more generally, force field parameter), HyperChem substitutes a default value. This occurs universally with the periodic table so all conceivable molecules will allow computations. Whether or not the results of such a calculation are realistic can only be determined by close examination of the default parameters and the particular molecular situation. ... 

Beynon, J.H., Mass Spectrometry and Its Application to Organic Chemistry, Elsevier, Amsterdam, 1960. Beynon, J.H., Saunders, R.A., and Williams, A.E., The Mass Spectra of Organic Molecules, Elsevier, Amsterdam, 1963. 

Since the six carbons shown above have 10 additional bonds, the variety of substituents they carry or the structures they can be a part of is quite varied, making the Diels-Alder reaction a powerful synthetic tool in organic chemistry. A moment s reflection will convince us that a molecule like structure [XVI] is monofunctional from the point of view of the Diels-Alder condensation. If the Diels-Alder reaction is to be used for the preparation of polymers, the reactants must be bis-dienes and bis-dienophiles. If the diene, the dienophile, or both are part of a ring system to begin with, a polycyclic product results. One of the first high molecular weight polymers prepared by this synthetic route was the product resulting from the reaction of 2-vinyl butadiene [XIX] and benzoquinone [XX] ... 

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). 

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. 

Dyestuff organic chemistry is concerned with designing molecules that can selectively absorb visible electromagnetic radiation and have affinity for the specified fiber, and balancing these requirements to achieve optimum performance. To be colored the dyestuff molecule must contain unsaturated chromophore groups, such as a2o, nitro, nitroso, carbonyl, etc. In addition, the molecule can contain auxochromes, groups that supplement the chromophore. Typical auxochromes are amino, substituted amino, hydroxyl, sulfonic, and carboxyl groups. 

Mullen, K. (1999). Organic chemistry and the synthesis of well-defined molecules, in Synthesis of Polymers, ed. Schltiter, A.-D. (Wiley-VCH, Weinheim) p. I. 

Theories of molecular stracture attempt to describe the nature of chemical bonding both qualitatively and quantitatively. To be useful to chemists, the bonding theories must provide insight into the properties and reactivity of molecules. The stractural theories and concepts that are most useful in organic chemistry are the subject of this chapter. Our goal is to be able to relate molecular stracture, as depicted by stractural formulas and other types of stractural information, such as bond lengths and electronic distributions, to the chemical reactivity and physical properties of molecules. 

The concepts of directed valence and orbital hybridization were developed by Linus Pauling soon after the description of the hydrogen molecule by the valence bond theory. These concepts were applied to an issue of specific concern to organic chemistry, the tetrahedral orientation of the bonds to tetracoordinate carbon. Pauling reasoned that because covalent bonds require mutual overlap of orbitals, stronger bonds would result from better overlap. Orbitals that possess directional properties, such as p orbitals, should therefore be more effective than spherically symmetric 5 orbitals. 

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