Visualization molecular extended

Orbital symmetry arguments or the Woodward-Hoffmann rules, as they are now commonly referred to are, however, not easily extended beyond planar tz systems. In great part, this is due to the difficulty of constructing and sketching by hand and visualizing molecular orbitals of three-dimensional systems, a situation which modem computer graphics has now completely altered. 

We have developed ultrahigh-precision coherent control based on this WPI, in which we have succeeded in visualizing and controlling the ultrafast evolution of a WP interference in a molecule with precisions on the picometer spatial and attosec-ond (as) temporal scales [37-39], This is the cutting edge of coherent control. We have utilized this ultrahigh-precision coherent control to develop a molecular computer that executes ultrafast Fourier transform with molecular wave functions in 145 fs [40,41], More recently, we have extended the target of our coherent control to wave functions delocalized in a bulk solid [42,43], In this account, we will describe these developments of our experimental toolbox and the outlook toward the coherent control around the quantum-classical boundary. 

Now we are ready to construct the molecular orbitals of buta-1,3-diene. The p orbitals on Cl through C4 overlap, giving an extended system of four p orbitals that form four pi molecular orbitals. Two MOs are bonding, and two are antibonding. To represent the four p orbitals, we draw four p orbitals in a line. Although buta-1,3-diene is not linear, this simple straight-line representation makes it easier to draw and visualize the molecular orbitals. 

There are molecular systems exhibiting 7r-bond fixation patterns that are entirely opposite to that induced by the Mills-Nixon effect [82,83,67]. Typical examples of this kind are provided by benzoborirene 33 and benzocyclopropenyl cation 34 (Fig. 19) These compounds represent extended 7r-systems relative to benzene itself since they encompass now empty 7r-orbitals at B and C+ atoms, respectively. The structural parameters offered by HF/6-31G [82] and MP2(fc)/6-31G [43] models are given in Table 10. Both molecules are planar. A salient feature of the aromatic CC bonds is their stretching relative to benzene at ortho and para positions. In contrast, meta bonds are more localized and shortened. Another striking property is a pronounced delocalization within the three-membered ring (aromatic pattern involving 27t electrons) as easily visualized by the resonance structures shown in Scheme 4. The same resonance mechanism is operative in benzocyclopropenyl cation. 

Figure 1. Extended molecules X, Xg-Pts and corresponding adducts Xg-02, Xg-Pt3-02 and Xs-Pt3-20. Xg = Co2Pt (1, 6 and 15), C03 (2, 7 and 16), Pt3 (3, 8 and 17), M3 (4, 9 and 18), Fc3 (5, 10 and 19), Pt6(ll, 12 and 20), Co3Pt3(13, 14 and 21). Trimer Pt3 (22) and its associated adducts (23-24) are shown as reference. Clusters without atomic or molecular oxygen are called complexes and those including them adducts. Atoms are color coded as follows Co (blue), Pt (yellow), Ni (lime green), Fe (aqua marine) and O (red). Most lines connecting atoms are for visual aid.

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