Second bond-order alterations

The insignificant alterations of the geometry, the charge distribution (see Fig. 13), the frontier orbitals, and the bond orders introduced as the educt is transferred into the activated complex point out that the latter is educt-like. However, as the activation entropies show, the reaction partners have already been arranged. For the first (AS = —161 AS° = —136 JK-1 mol-1) as well as for the second propagation... 

Results (Table I) from refinement of the powder neutron diffraction data for the Ce doped material, Bi 8 0 2 3 12 that significant structural alterations have resulcea from Ce incorporation into the solid The three Mo atoms are no longer chemically equivalent The coordination about Mo(l) is unchanged from that of the parent compound A second Mo atom contains two short (double) bonds to oxygen atoms These molybdate dioxo (dimolybdenyl) groups are believed to be an important feature for selective oxidation catalysis (7 ) The third Mo coordination sphere contains no Mo=0 bond Bond order calculations (27) about... 

The second-order interactions occur between the initial CH and the other two bold groups in the fragment -CH-CH2-CH2—CH(CH3)-CH-. Rotation about bond i alters the position of the methyl group, which was not true in the prior consideration of the second-order interactions that are incorporated in UcQx- The matrices of second-order interactions differ for the two bonds. 

Thus the only interactions that can alter the total energy of the molecule are those between filled bonding orbitals and empty antibonding orbitals. Since these differ greatly in energy, the corresponding second order perturbations will be relatively small, for the energy difference Em — E appears in the denominator of the expression for the perturbation (Eq. (153)). 

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