Molecular orbitals correlation diagrams

SYMMETRY PROPERTIES OF MOLECULAR ORBITALS CORRELATION DIAGRAMS... 

Fig. 8. Molecular orbital correlation diagram for H2 D2 - 2 HD assuming D2h symmetry throughout the reaction.

In addition to molecular-orbital correlation diagrams, potential-energy curves for the diatoms in asymptotic reactant and product regions of the system are considered 451... 

Valuable insight, particularly with regard to the effects of electronic excitation on reaction cross sections and reaction dynamics, has also been achieved without accurate knowledge of the actual potential surfaces, through the use of molecular-orbital correlation diagrams. Adiabatic correlation rules for neutral reactions involving polyatomic intermediates were developed by Shuler 478 These were adapted and extended for ion-neutral interactions by Mahan and co-workers.192,45 479,480 Electronic-state correlation diagrams have been used to deduce the qualitative nature of the potential surfaces that control ion-neutral reaction dynamics. The dynamics of the reaction N+(H2,H)NH+ and in particular the different behavior of the N + (3P) and N + ( Z)) states,123 for example, have been rationalized from such considerations (see Fig. 62). In this case the... 

Figure 4 Molecular orbital correlation diagram for the ortho addition of benzene to ethene. A plane of symmetry (a) is retained during the transition from benzene plus ethene to bicyclo[4.2.0]octa-2,4-diene.

From the orbital correlation diagram derived by Bryce-Smith [38], it was deduced that the ortho cycloaddition is forbidden from the lowest excited singlet state of benzene and the ground state of ethene. Van der Hart et al. [189] have constructed molecular orbital and state correlation diagrams for the ortho photocycloaddition of benzene to ethene. The molecular orbital correlation diagram differs from that given by Bryce-Smith, because natural correlations have been used. From a topological point of view, it seems less desirable to correlate the tt... 

Figure 7 Natural molecular orbital correlation diagram for the ortho addition of benzene...

H. E. Zimmerman, /. Am. Chem. Soc., 88, 1566 (1966). Molecular Orbital Correlation Diagrams, Mobius Systems, and Factors Controlling Ground- and Excited-State Reactions. II. 

On molecular orbital correlation diagrams, the occurrence of Mobius systems in cyclization reactions, and factors controlling ground- and excited- state reactions. I. J. Amer. chem. Soc. 88, 1564 (1966),... 

The [1 +4] cycloaddition of sulfur dioxide and the dienes is stereospecific in agreement with predictions on the basis of molecular orbital correlation diagrams. 

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

Fig 4. Molecular orbital correlation diagram interpolating between Rh and Td for Na4. Names of MOs for C2v and D2h indicated on the left side, while those for Td are on the right side. 

The molecular orbital correlation diagram can be connected to the jellium model (25). For example, the Ipi and lpx,y> subshells in the jellium model are correlated with the 6b 1 (C2v notation), 6b2, and lOaj in the MO diagram. The X axis in the present work corresponds to the Z axis in the jellium model. Therefore the molecular orbital calculation gives essentially the same picture as the jellium model, with regard to the AM and AE clusters. The present work also gives a direct view of these molecular orbitals, as was shown in Fig 6. 

Molecular Orbital Correlation Diagram for o Bond Metathesis... 

Figure 33 shows molecular orbital correlation diagrams for the disrotatory (51) and conrotatory (52) electrocyclic ring opening pathways for cyclobutene. With a total of four... 

As an epilogue to this discussion of statistical models, we note recent interest in formulating reasons in terms of molecular orbital correlation diagrams to show why the statistical model may be invalid. For example, an interesting explanation has been given for the relative cross sections of the series of reactions X (H2,H)XH , where X = He, Ne, Ar, and For the last two systems, there is orbital correlation... 

Molecular orbital correlation diagram for ( 4s -I- cycloaddition of ozone and ethene. (Adapted from reference 122.)... 

Most of the theoretical methods used to correlate chemical reactivity trends implicitly (or in some cases explicitly) use a model of interacting diabatic surfaces in which the transition structure is associated with an avoided crossing of a reactant-like or a product-like diabatic surface. In the molecular-orbital correlation diagram approach of Woodward and Hoffmann or the frontier orbital method of Fukui, the molecular orbitals of the fragments are first mixed to form the MO of the supermolecule and then the electrons are assigned to various configurations of these supermolecule MO. We shall refer... 

Zimmerman HE (1966) Molecular orbital correlation diagrams, Mobius systems and factors controlling grormd and excited state reactirms I and IL J Am Chem Soc 88 (1564-1566) 1566-1567... 

Teller E. The crossing of potential surfaces. J Phys Chem. 1937 41 109-116. Zimmerman HE. Molecular orbital correlation diagrams, Mobius systems, and factors controlling ground- and excited-state reactions. II. J Am Chem Soc. 1966 88 1566-1567. 

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