Hybrid orbital, definition

Definition In sp hybridisation of carbon the 2s orbital is mixed with one of the 2p orbitals (e.g. 2pJ to form two sp hybrid orbitals or equal energy. This leaves two 2p orbitals unaffected (i.e. unhybridised) (2p and 2p ) with slightly higher energy than the hybridised orbitals (Following fig.). 

About at the same time, though published somewhat later, we were concerned with the calculation of valence state electronegativities following the original definition of Mulliken[23,24] and in turn we expressed the energy of an atom as a function of the charge q in a valence orbital, i.e. a hybrid orbital ready for bonding as... 

The d orbitals in an atom also take part in hybridization, leading to hybrid orbitals such as dsp" or d sp. There is a definite relationship between the structure of molecules and the hybridization of orbitals. Table 3.1 (p. 62) lists various hybrid orbitals and the resulting structures. "... 

As Figure 15-2 shows, each of these fragments has a single electron in a hybrid orbital at the vacant site of the parent polyhedron. These orbitals are sufficiently similar to meet Hoffmann s isolobal definition. Using Hoffmann s symbol to designate... 

For the molecule BeH2, which has linear geometry, the appropriate hybrid orbitals of Be in the definition of the functions Xi, quasi-localized in each formal Be-H bond, are two coUinear sp hybrid orbitals (see Chapter 3) ... 

Each 0 has two bonds by onr definition. Therefore, we expect tip hybrid orbitals in the molecule for each C. 

Carbonaceous solids that are inside the triangle in Fig. 2.4 obviously contain mixtures of the three hybridization states. Japanese researchers [33, 34] recently coined the term carbon alloys to designate materials typically made up of carbon atoms in multicomponent systems, where the components undergo physical or chemical interactions with each other. This very broad concept extends to mixtures of different phases (as occurs, for instance, in carbon-carbon composites), and also to materials containing heteroatoms. The interesting point in the present context is that, according to the above definition, carbon atoms with different hybrid orbitals are considered as different components. 

Atoms that are linked by electron-pair bonds are positioned so that orbital overlap is maximised. The orbitals used are also sensitive to bond overlap and hybridisation, so that atomic orbitals frequently mix to give hybrid orbitals with greater overlapping power. The shapes of atomic orbitals and hybrid orbitals are quite definite and point in fixed directions. This leads to the fact that covalent bonding is directional. From a geometrical point of view, the array of covalent bonds in a solid resembles a net. 

Such a definition of flie hybrid orbitals is not unique, sinee the loealized orbitals used are also not unique. However, as shown above, this ambiguity is of seeondary importance. The advantages of such an approach to hybridization are as follows ... 

To understand this definition, it is useful to depict cycloaddition reactions with dashed lines representing bonding interactions that will be present in the product of the reaction.The effect of the cycloaddition shown for the [ 2j -I- process in Figure 11.84(a) is to pull up the inner lobe of the sp hybrid orbital on C3 so that it overlaps with the upper lobe of the p orbital... 

This result leads us to the definition of hybrid atomic orbitals obtained by combination of valence shell s and p AOs of the same atom. The properties of such hybrid orbitals are examined. Even though hybridization of an atom requires energy, this energy may be more than compensated by the formation of a stronger bond. 

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