Atomic bonding secondary

Bond cleavage is more probable at branched carbon atoms tertiary > secondary > primary. The positive charge tends to remain with the branched carbon. 

The atoms of a molecule are held together by primary bonds. The attractive forces which act between molecules are usually referred to as secondary bonds, secondary valence forces, intermolecular forces or van der Waals forces. 

In most paraffins there will be different numbers of hydrogens attached to the carbon atoms. There are four types of carbon atoms with names corresponding to the number of bonds made with other carbon atoms or functional groups. These names are primary, secondary, tertiary, and quaternary, as shown above. In a compound such as isopentane, there are three primary carbon atoms, one secondary, and one tertiary. 

The theory as presented so far is clearly incomplete. The topology of the density, while recovering the concepts of atoms, bonds and structure, gives no indication of the localized bonded and non-bonded pairs of electrons of the Lewis model of structure and reactivity, a model secondary in importance only to the atomic model. The Lewis model is concerned with the pairing of electrons, information contained in the electron pair density and not in the density itself. Remarkably enough however, the essential information about the spatial pairing of electrons is contained in the Laplacian of the electron density, the sum of the three second derivatives of the density at each point in space, the quantity V2p(r) [44]. 

Data for the specific rate coefficients for abstraction from CH bonds have been derived from experiments with hydrocarbons with different distributions of primary, secondary, and tertiary CH bonds. A primary CH bond is one on a carbon that is only connected to one other carbon, that is, the end carbon in a chain or a branch of a chain of carbon atoms. A secondary CH bond is one on a carbon atom connected to two others, and a tertiary CH bond is on a carbon atom that is... 

Replacing one or several of the hydrogen atoms in methane by one or several other atoms than hydrogen automatically creates secondary or tertiary C-H bonds. Secondary and tertiary C-H bonds are more reactive than a primary C-H bond. During oxidation reactions, this leads to an easier oxidation of the reaction products than methane, and consequently to a low(er) reaction selectivity. Such reactions therefore produce complicated reactant mixmres that require costly... 

The bromine atom then adds to the alkene, generating a new carbon radical. In the case of propene, as shown, the bromine atom bonds to the terminal carbon atom. In this way, the more stable secondary radical is generated. This is preferred to the primary radical generated if the central carbon were attacked. The new secondary radical then abstracts hydrogen from a further molecule of HBr, giving another bromine atom that can continue the chain reaction. 

A carbon atom is classified as primary (1°), secondary (2°), tertiary (3°) and quaternary (4°) depending on the number of carbon atoms bonded to it. A carbon atom bonded to only one carbon atom is known as 1° when bonded to two carbon atoms, it is 2° when bonded to three carbon atoms, it is 3°, and when bonded to four carbon atoms, it is known as 4°. Different types of carbon atom are shown in the following compound. 

As expected, JV-pentafl uorophenylpiperidine iV-oxide undergoes substitution at positions ortho or para to the nitrogen atom [23], Secondary amines give the ortho products because of their capability for hydrogen bonding in the transition state. 

Hydrogen atoms bonded to nitrogen, as well as those attached to carbon, are replaced by fluorine upon perfluorination of primary and secondary amines (Fig. 37) [101, 102]. Perfluorinated tertiary amines have also been prepared (Figs. 38 and 39) [78,103]. 

A secondary bond , as defined by Alcock [6-8], is an interaction between two atoms characterized by a distance longer than the sum of the covalent radii but shorter than the sum of the van der Waals radii of the corresponding atoms. Such secondary interactions are weaker than normal covalent or dative bonds, but strong enough to connect individual molecules and to modify the coordination geometry of the atoms involved. They are often present in a crystal, thus resulting in self-assembled supermolecules or supramolecular architectures. For gold complexes,... 

The difference is in the number of carbon atoms bonded to the carbon bearing the -OH group. For a primary alcohol, there is one. For a secondary alcohol there are two and for a tertiary alcohol, there are three. 

If the hydrogens of ammonia are replaced by alkyl or aryl groups, amines result. Depending on the number of carbon atoms bonded directly to nitrogen, amines are classified as either primary (one carbon atom), secondary (two carbon atoms), or tertiary (three carbon atoms) (Table 33.1). 

The second route of getting free radical center near is mediated by low-molecular free radicals or compounds which are either present in the polymer or are gradually formed there by fragmentation reactions. While tertiary peroxy radicals propagate only by abstraction of hydrogen atom from surrounding C —H bonds, secondary peroxy radicals may easily cleave to hydroxy radicals and ketones as follows ... 

The names of the secondary-butyl (sec-butyl) and tertiary-butyl (ferf-butyl or f-butyl) groups are based on the degree of alkyl substitution of the carbon atom attached to the main chain. In the, vec-butyl group, the carbon atom bonded to the main chain is secondary (2°), or bonded to two other carbon atoms. In the ferf-butyl group, it is tertiary (3°), or bonded to three other carbon atoms. In both the n-butyl group and the isobutyl group, the carbon atoms bonded to the main chain are primary (1°), bonded to only one other carbon atom. 

Classification of alcohols. Alcohols are classified according to the type of carbon atom (primary, secondary, or tertiary) bonded to the hydroxyl group. Phenols have a hydroxyl group bonded to a carbon atom in a benzene ring. 

An amide of the form R—CO—NH2 is called a primary amide because there is only one carbon atom bonded to the amide nitrogen. An amide with an alkyl group on nitrogen (R—CO—NHR ) is called a secondary amide or an A-substituted amide. Amides with two alkyl groups on the amide nitrogen (R—CO—NR2) are called tertiary amides or /V,/V-disubstituted amides. 

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