C2v point group

That no degenerate molecular orbitals arose in the above examples is a result of the fact that the C2v point group to which H2O and the allyl system belong (and certainly the... 

Analogous to the three states we ean also ehoose eombinations of the five degenerate states whieh ean be labeled with "pure" C2v point group labels ... 

The n ==> n transition thus involves ground Ai) and exeited Ai) states whose direet produet (Ai x Ai) is of Ai symmetry. This transition thus requires that the eleetrie dipole operator possess a eomponent of Ai symmetry. A glanee at the C2v point group s eharaeter table shows that the moleeular z-axis is of A symmetry. Thus, if the light s eleetrie field has a non-zero eomponent along the C2 symmetry axis (the moleeule s z-axis), the n ==> 71 transition is predieted to be allowed. Light polarized along either of the moleeule s other two axes eannot induee this transition. 

FIGURE 11. The molecular model (C2v point group) and torsional form of (CC13)2S0231. The projection formula represents a view along one of the S—C bonds. 

It is easy to see that these point groups are related to one another, but that they specify quite different rotational s mmetries. In contrast, C2 has a 2-fold rotation axis but no horizontal symmetry (but C2h has horizontal symmetry). Contrast the C2v point group with vertical symmetry to the C2... 

Multiplication tables can be constructed for the combination of symmetry operations for other point groups. However, it is not the multiplication table as such which is of interest. The multiplication table for the C2v point group is shown in Table 5.2. If we replace E, C2, and cryz by +1, we find that the numbers still obey the multiplication table. For example,... 

In this molecule the diene moiety assumes the C2V symmetry and the prominent feature of its near-UV absorption spectrum is the 240 nm band (fimax 3500), assigned6 to the same transition r - jt L, now characterized by xAi - lB2 symmetry in the C2V point group (see Appendix, Section V). 

Direct Product Table for C2v Point Group in Coordinate Space with / to Give the D2h Point Group in Momentum Space... 

The H3 center is well known in the steady-state luminescence spectra of diamonds. It belongs to the C2v point group, the ground state being level and the excited state from which luminescence takes place a Bi. Both emis-... 

As you can see, the symmetries of each of these states cannot be labeled with a single irreducible representation of the C2V point group. For example, lpxOCpzOCl is xz (B j) and... 

The 90° form of the water molecule belongs to the C2v point group. There... 

The molecule belongs to the C2v point group. It may be set up with respect to the z axis as shown in Figure 6.10. A MO diagram is shown in Figure 6.11. 

UV Spectrum. The lowest energy electronic transition (HOMO-LUMO) is no n( (y leading to the nn state, which has A2 symmetry in the local C2v point group. The transition to this state is symmetry forbidden (it is quadrupole allowed but dipole forbidden) and will be expected to be weak. 

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