Energy level diagrams, hydrogen bonds

Draw simple molecular orbital energy-level diagrams to indicate how the bonding in the saline hydrides, such as NaH or KH, differs from that between hydrogen and a light p-block element such as carbon or nitrogen. 

Fig. 1 Energy diagrams for hydrogen bonds between groups of equal pK. (a( Weak hydrogen bond 0-0 distance 2.8 A. (b) Low-barrier hydrogen bond (2.55 A) the hydrogen diffusely distributed, (c) Single-well hydrogen bond (2.29 A). Horizontal lines are zero point energy levels for hydrogen (upper) and deuterium (lower).

Draw an energy level diagram for the excited state of H2. Is there still a bond between the hydrogens ... 

Molecular Orbitals of H2. The simplest example of a diatomic molecule is H2. For this molecule, the only atomic orbitals available are the Is orbitals of the hydrogens. These orbitals interact to yield bonding als and antibonding als molecular orbitals the molecular orbital energy level diagram is shown in Figure 2-3. (Subscripts are often used to designate the atomic orbitals from which the molecular orbitals are derived.)... 

Although we have used the hydrogen molecule to illustrate molecular orbital formation, the concept is equally applicable to other molecules. In the H2 molecule we consider only the interaction between Is orbitals with more complex molecules we need to consider additional atomic orbitals as well. Nevertheless, for all s orbitals, the process is the same as for Is orbitals. Thus, the interaction between two 2s or 3 orbitals can be understood in terms of the molecular orbital energy level diagram and the formation of bonding and antibonding molecular orbitals shown in Figure 10.22. 

Knowing that only the 2p orbitals of oxygen interact significantly with the Is orbital of hydrogen, complete the MO energy-level diagram for OH. Place the correct number of electrons in the energy levels. Estimate the bond order for OH. 

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