Dsp3 hybrid orbitals

The 5d orbital used would be the dz2, which would participate in hybridization with the 5s and three 5p orbitals to give five dsp3 hybrid orbitals disposed towards the vertices of a trigonal bipyramid. The five pairs would assume a trigonally bipyramidal distribution, and it is logical for the fluorine atoms to be as far away from each other as possible to give a linear molecule. The alternative approach would divide the... 

In spite of all the theoretical evidence, accumulated over many years, it is still commonplace for students to be taught that the existence of hypercoordinate molecules such as SF and PFri relies on the utilization of d orbitals to expand the octet . Indeed, even models based on d sp , dsp2 and dsp3 hybrid orbitals or pn-dn back-bonding are still in use to describe hypercoordinate bonding to second-row elements. Of course, the consensus view that has emerged from most of the... 

Although it will not be important for our purposes, the dsp3 hybrid orbital set is different from the hybrids we have considered so far in that the hybrid orbitals pointing to the vertices of the triangle (often called the three equatorial hybrid orbitals) are slightly different in shape than the other two (the axial orbitals). This situation stands in contrast to the sp, sp1, and sp3 hybrid sets in which each orbital in a particular set is identical in shape to the others. 

A set of dsp3 hybrid orbitals on a phosphorus atom. Note that the set of five dsp3 orbitals has a trigonal bipyramidal arrangement. (Each dsp3 orbital also has a small lobe that is not shown in this diagram.)... 

Lastly, we consider a system with non-equivalent positions. An example of such a system is the trigonal bipyramidal molecule AX5 with symmetry. As discussed previously, one possible scheme is the dsp3 hybridization, where dz2 is the only d orbital participating. 

For a d1 ion such as Co2+, an additional possibility exists. The electron configuration of Co2+ is 3d7 so if the seven electrons in the 3d orbitals are forced to occupy four orbitals, one orbital is empty. Therefore, a set of dsp3 hybrids can form, and this is the hybrid orbital type for a trigonal bipyramid. This is exactly the behavior exhibited in the complex [Co(CN)5]3 ... 

Thus the central iodine is dsp3 hybridized. Three of these hybrid orbitals hold lone pairs, and two of them overlap with sp3 orbitals from the other two iodine atoms to form cr bonds. 

This type of hybridization is known as sp3d (or dsp3, depending on where you look). The remaining type of hybridization, known as sp3cf (cfsp3), can be seen in the hybridization of sulfur in the compound sulfur hexafluoride, SF6. In Figure 7.21 below, note how two electrons are promoted to the d orbitals ... 

Valence bond theory predicts the hybridization of orbitals, which occurs when an atom promotes an electron from a lower to a higher energy level in order to form more bonding pairs. You should be familiar with the five types of hybridizations (sp, sp2, sp3, dsp3, cfsp3). 

This structure is somewhat unusual in that the two bonds in axial positions are longer than those in the equatorial positions. The hybrid bond type for the trigonal bipyramid is sp3d (or dsp3 in some cases). However, in reality this is a combination of dp (linear) and sp2 (trigonal planar) hybrids so the orbitals used in the axial and equatorial positions are not equivalent, and this is apparent from the bond lengths shown on the preceding structure. 

Note that the lone pairs are placed in the plane where they are 120 degrees apart. Accommodating five pairs at the vertices of a trigonal bipyramid can be explained if the xenon atom adopts a set of five dsp3 orbitals. Each fluorine atom has four electron pairs and can be assumed to be sp3 hybridized. The XeF2 molecule has a linear arrangement of atoms. 

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