Covalent bonds in organic molecules

Subsequently, the activated monomer molecule M, a molecule in the excited state with an energy reserve of 8-5 eV exceeding the strength of covalent bonds in organic molecules ( 3 eV), decomposes with the formation of free radicals, some of which are able to initiate... 

Side-to-side overlap of two p atomic orbitals forms a it bond. All other covalent bonds in organic molecules are rr bonds. 

Total organic carbon TOC Carbon atoms covalently bonded in organic molecules... 

All other covalent bonds in organic molecules are tr bonds. 

When the difference in electronegativities is great, the orbital may be so far over to one side that it barely covers the other nucleus. This is an ionic bond, which is seen to arise naturally out of the previous discussion, leaving us with basically only one type of bond in organic molecules. Most bonds can be considered intermediate between ionic and covalent. We speak of percent ionic character of a bond, which indicates the extent of electron-cloud distortion. There is a continuous gradation from ionic to covalent bonds. 

NUCLEOPHILE. An ion or molecule that donates a pair of electrons to an atomic nucleus to form a covalent bond. The nucTeus that accepts the electrons is called an electrophile. This occurs, for example, in the formation of acids and bases according to the Lewis concept, as well as in covalent bonding in organic compounds. 

Most bonds in organic molecules, however, are covalent bonds in which electrons are shared between two atoms. Sharing electrons is a way to enable each... 

The Townes-Dailey approach is also often used in evaluating the covalent character of carbon-halogen bonds in organic molecules. Again the temperature... 

To remedy this situation and reduce the often excessive gel s polarity, the silanol groups are exploited in order to provide sites of covalent bonding for organic molecules. Bonded silica gel, modified in this way, behave as a liquid in that the separation mechanism now depends on the partition coefficient instead of adsorption coefficient. These covalently bonded phases, whose polarity can be easily adjusted, constitute the bases of the reversed phase polarity partition chromatography or RP-HPLC, used in the majority of HPLC separations. Two types of syntheses lead to monomeric or polymeric bonded surfaces ... 

The bonds in organic molecules are generally of the two-electron covalent type. Organic reactions involve the breaking and making of covalent bonds. 

As chemists developed a better understanding of covalent bonding in organic compounds, it became obvious that, for a great many molecules and ions, no single Lewis structure provides a truly accurate representation. For example, Figure 1.11 shows three Lewis structures for the carbonate ion, each of which shows carbon bonded to three oxygen atoms by... 

Modern analytical pyrolysis has conventionally been canied out only by thermal energy to break some covalent bonds in the sample molecules at elevated temperatures to produce smaller and/or volatile fragments (pyrolyzates). On the other hand, the reactive pyrolysis in the presence of organic alkaline, such as tetramethylammonium hydroxide [(CH / NOH] (TMAH) has recently received much attention especially in the field of chai acterizing condensation polymers. 

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