Heteronuclear energy diagram

Figure 6.7. Schematic energy diagram of the splitting in a heteronuclear molecule.

The use of high-power resonant RF to collapse coupling interactions to zero. Versions include homonuclear (observed and decoupled nuclei have the same y), heteronuclear (observed and decoupled nuclei with different y), and noise (for wide frequency coverage). With low-power selective irradiation it is possible to map coupled-energy diagrams and transfer polarization. 

FIGURE 3.33 A typical d molecular orbital energy-level diagram for a heteronuclear diatomic molecule AB the relative contributions of the atomic orbitals to the molecular orbitals are represented by the relative sizes of the spheres and the horizontal position of the boxes. In this case, A is the more electronegative of the two elements. 

The molecular orbital energy-level diagrams of heteronuclear diatomic molecules are much harder to predict qualitatitvely and we have to calculate each one explicitly because the atomic orbitals contribute differently to each one. Figure 3.35 shows the calculated scheme typically found for CO and NO. We can use this diagram to state the electron configuration by using the same procedure as for homonuclear diatomic molecules. 

Fig. 10.22. Diagram showing the cross-polarization from protons, H, to a heteronucleus, X, such as carbons. Heteronuclear dipolar coupling enables the transfer of magnetization from H to X, such as protons to carbons. Homonuclear dipolar coupling between the abundant protons enables the redistribution of proton spin energy through spin diffusion.

Energy level diagram of a heteronuclear diatomic molecule. 

Molecular orbital correlation diagrams for heteronuclear diatomics start with the energy levels of the more electronegative atom displaced downward, because... 

FIGURE 6.19 Correlation diagram for heteronuclear diatomic molecules, AB. The atomic orbitals for the more electronegative atom (B) are displaced downward because they have lower energies than those for A. The orbital filling shown is that for (boron monoxide) BO. 

The following is a molecular orbital energy level diagram for a heteronuclear diatomic molecule, XY, in which both X and Y are from Period 2 and Y is slightly more electronegative. This diagram may be used in answering questions in this section. 

We can extend the method to heteronuclear diatomics with relative ease. Since the heteronuclear molecule does not have the nuclear exchange symmetry the g and u character is lost, but the rest of the notation remains the same. The correlation diagram becomes more complicated because of the difference in energies of the electron on the two different separated atoms. It is worth noting that isoelectronic species such as N=N, C=0,... 

If we assume that the energy-level diagrams for homonuclear diatomic molecules shown in Figure 9.43 can be applied to heteronuclear diatomic molecules and ions, predict the bond order and magnetic behavior of (a) CO, (b) NO, (c) OF, ... 

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