Oxygen hybrid orbitals

Oxygen forms two bonds by utilising its half filled sp3 hybrid orbitals when it forms the H20 molecule with hydrogen. 

An oxygen atom can also form a double bond to carbon thus in propanone (acetone), Me2C=Q , the oxygen atom could use three sp2 hybrid orbitals one to form a a bond by overlap with an sp2 orbital of the carbon atom, and the other two to accommodate the two lone pairs of electrons. This leaves an unhybridised p orbital on both oxygen and carbon, and these can overlap with each other laterally (cf. C=C, p. 9) to form a n bond  

Let s begin assigning valence electrons by half-filling three sp2 hybrid orbitals on the sulfur atom (atom A) and one sp2 hybrid orbital on each of the oxygen atoms (atoms B, C and D) 

Phosphorus and sulfur are the third-row analogs of nitrogen and oxygen, and the bonding in both can be described using hybrid orbitals. Because of their positions in the third row, however, both phosphorus and sulfur can expand their outer-shell octets and form more than the typical number of covalent bonds. Phosphorus, for instance, often forms five covalent bonds, and sulfur occasionally forms four. 

The oxygen m furan has two unshared electron pairs (Figure 11 16c) One pair is like the pair m pyrrole occupying a p orbital and contributing two electrons to complete the SIX TT electron requirement for aromatic stabilization The other electron pair m furan IS an extra pair not needed to satisfy the 4n + 2 rule for aromaticity and occupies an sp hybridized orbital like the unshared pair m pyridine The bonding m thiophene is similar to that of furan 

Clays contain aluminum oxides in addition to silicon as Si02 and its polymeric forms. Again, there are the p orbitals of oxygen and sp-hybridized orbitals from aluminum, which may result in end-on-end or side-by-side bonding with the same restrictions encountered with silicon. 

It can be imagined that the bonds can be broken at any location, that is, with an oxygen, hydroxy, silicon, or aluminum exposed. In this case, it could further be imagined that s-, p-, and sp3-hybridized orbitals would be on the surface. This 

Which orbitals hold these lone pairs We answer this question by taking an inventory of the valence orbitals. For the inner atom, the s hybrid orbitals account for the 2 S orbital and the two 2 p orbitals that lie in the plane of the molecule, and the third p orbital, perpendicular to the molecular plane, is part of n system. All of the valence orbitals of the inner oxygen atom are accounted for. For each outer atom, one p orbital in the plane of the page contributes to the a bonds, and the p orbital perpendicular to the plane of the page is part of the n system. The remaining valence orbitals on each outer atom are the 2. S orbital and the 2 orbital that lies in the molecular 

The molecule has 16 valence electrons. Its Lewis stmcture shows that the molecule has two double bonds, with a steric number of 2 for the carbon atom. Consistent with this, the molecule is linear. Figure 10-39 shows the two a bonds formed by end-on overlap between sp hybrid orbitals on the carbon atom and 2 Pz atomic orbitals of oxygen. 

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