Charge on carbon atom

In addition, recent calculations of the partial charges on carbon atoms of the alkyl chains of several trialkylphosphates have indicated that in all cases, the Ca-atoms possessed the highest density of positive charge (294). 

As is known, the greater the number of fluorine atoms in the organic molecule, the higher the positive charge on carbon atoms this is due to the difference in electronegativity between C and F. This effect, in turn, enhances the reactivity of fluorine atoms attached at the C=C or C-F bond in an aromatic ring. As a result, intramolecular nucleophilic cyclizations... 

Notably, the HOMO and LUMO energies and electron densities were also correlating this property. The involvement of the net atomic charge on carbon atom in the 2-position (q2) suggests that this might be the site for activity. In addition, linear... 

There are two forms in which the negative charge is on carbon atom (9), one each with the negative charge on carbon atoms (3), (6), or (8), and none with the negative charge on atoms (4), (5), (7),... 

Here AMINE is an indicator variable for aliphatic amines, NH is the number of N-H single bonds in the molecule, ABSCQ is the sum of absolute values of atomic charges on carbon atoms, V is the molecular volume, and ABSHQ is the sum of absolute values of atomic charges on hydrogen atoms. Other parameters used are the same as in the log Pq/u model (equation 7). 

A formal charge is a charge associated with an atom that does not exhibit the expected number of valence electrons. When calculating the formal charge on an atom, we first need to know the number of valence electrons the atom is supposed to have. We can get this number by inspecting the periodic table, since each column of the periodic table indicates the number of expected valence electrons (valence electrons are the electrons in the valence shell, or the outermost shell of electrons— you probably remember this from high school chemistry). For example, carbon is in Column 4A, and therefore has four valence electrons. Now you know how to determine how many electrons the atom is supposed to have. 

From all of the cases above (oxygen, nitrogen, carbon), you can see why you have to know how many lone pairs there are on an atom in order to figure out the formal charge on that atom. Similarly, you have to know the formal charge to figure out how many lone pairs there are on an atom. Take the case below with the nitrogen atom shown ... 

Since electronegativity is the measure of an element s affinity for electrons (how willing the atom will be to accept a new electron), we can say that a negative charge on oxygen will be more stable than a negative charge on carbon. 

Alkene protonation at pore mouths can exclusively lead to secondary carbenium ions. In addition, the alkene standard protonation enthalpies increase with the number of carbon atoms inside the micropore because charge dispersive effects are supposed to be more effective on carbon atoms inside the micropores. 

FeC03 This ionic compound contains the carbonate polyatomic anion, C O3. The -2 charge on carbonate requires that iron have +2 oxidation number (Guideline 2). In the carbonate anion, each oxygen atom is -2, for a total of-6. The oxidation numbers must add up to the net charge on the anion (-2), so the carbon atom must have an oxidation number of +4. 

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