Hydrogen orbital interaction diagrams

Orbital interaction diagram and EHT calculations show that the 1,2 intramolecular shift of hydrogen is symmetry disfavored [10]. In presence of a transition metal fragment to which the alkyne coordinates, the activation energy is considerably lower. This has been attributed to the tendency of H to shift as a proton rather than as a hydride. 

Figure 10.2. Orbital interaction diagrams for symmetrical two-center hydrogen bonding.

Figure 10.3. Orbital interaction diagrams for a) symmetrical three-center hydrogen bonding and b) bifurcated hydrogen bonding.

Figure 2.6 The left side shows the orbital interaction diagram for two hydrogen atoms and the right side shows the interaction of two helium atoms (see molecular orbitals drawn in Fig. 1.6).

Fig. 1.17 An orbital interaction diagram for the formation of H2 from two hydrogen atoms. By the aufbau principle, the two electrons occupy the lowest energy (bonding) molecular orbital.

Note from Figure 1.39 that the orbital interaction diagram is constructed without reference to electrons. Only after the diagram has been constructed do we have to worry about electrons. But now let s count them up and put them in the available molecular orbitals. In the construction of H2, each hydrogen atom brings one electron. In Figure 1.40, these electrons are placed in the appropriate It i orbitals /(Ha) and /(Hb). The spin direction of the elec-... 

We see in Section 21.5 that a R3P-AU fragment has very similar bonding properties compared to a hydrogen atom Construct an orbital interaction diagram for H3P-AU by interacting the HOMO of PH3 (which has an ionization potential of 10.0 eV) with the s and p AOs of Au (s and pHn= 10.9 and 5.6 eV, respectively). The d AOs of Au lie a very low energy and to a first approximation will not mix too heavily into the other MOs. Draw out the resultant MOs and indicate the orbital occupancy. 

I 4.1 I. Construct an orbital interaction diagram for a T -shaped AH3 unit by interacting a Dooh AH2 fragment with a hydrogen atom. Draw out the orbital shapes. 

The construction of the pair of (bond orbitals is carried out by combining a carbon hybrid with the Is orbital on hydrogen in a manner similar to the construction of the CC bond orbitals. The interaction diagram is shown below in Fig. 3. The bonding orbital is occupied by the two bond electrons. These two... 

The interaction diagrams of Fig. 40 show the various orbital interactions which obtain in the two geometries. However, before we make a one-to-one comparison of these interactions, a few remarks regarding the effect of bending upon the hydrogen group orbitals is necessary. 

Figure 10.9 shows the orbital interactions for typical hydrogen atom transfer reaction. It is in fact the same diagram that described proton and hydride transfers (Figures 10.1 and... 

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