Mulliken relationship

The relationship between the herbicidal activity of 1,2,5-oxadiazole iV-oxides and some physicochemical properties potentially related to this bioactivity, such as polarity, molecular volume, proton acceptor ability, lipophilicity, and reduction potential, were studied. The semi-empirical MO method AMI was used to calculate theoretical descriptors such as dipolar moment, molecular volume, Mulliken s charge, and the octanol/water partition coefficients (log Po/w) <2005MOL1197>. 

The nitrosonium cation bears a formal relationship to the well-studied halogens (i.e. X2 = I2, Br2, and Cl2), with both classes of structurally simple diatomic electron acceptors forming an extensive series of intermolecular electron donor-acceptor (EDA) complexes that show well-defined charge-transfer absorption bands in the UV-visible spectral region. Mulliken (1952a,b 1964 Mulliken and Person, 1969) originally identified the three possible nonbonded structures of the halogen complexes as in Chart 7, and the subsequent X-ray studies established the axial form II to be extant in the crystals of the benzene complexes with Cl2 and Br2 (Hassel and Stromme, 1958, 1959). In these 1 1 molecular complexes, the closest approach of the... 

The relationship between the Mulliken definition and that of Jaffe can be shown quite amply. Taking Eq. 5.62 and substituting q +1, we know that the energy, E, of the system will be that of the +1 cation, or the first ionization energy. Likewise for <7=1. the energy will be the negative29 of the electron affinity, so ... 

The Mulliken electronegativities have a good linear relationship with the Pauling values, and the former are usually adjusted for consistency... 

The character tables usually consist of four main areas (sometimes three if the last two are merged), as is seen in Table 4-5 for the C3v and in Table 4-7 for the C2h point group. The first area contains the symbol of the group (in the upper left corner) and the Mulliken symbols referring to the dimensionality of the representations and their relationship to various symmetry operations. The second area contains the classes of symmetry operations (in the upper row) and the characters of the irreducible representations of the group. 

To fair approximation the Mulliken values, based on ground-state energies, are proportional to Pauling values by the relationship [119]... 

Computed atomic charge is subjective because its value depends on the algorithm used (their values cannot be observed experimentally). Regardless of the algorithm used, however, trends and relative charge values are sometimes useful. To more directly illustrate the relationship between the coefficients, c,>, in Eq. [5], and the electron density, we briefly describe Mulliken population... 

Figure 1 shows the linear correlation between F chemical shift and solvent donicity. No relationship exists between chemical shifts and dipole moments or polarizabilities of the solvent molecules. This result is particularly significant in that it shows that the functional approach can be successfully applied even to weak chemical interactions, for example, to interactions that are usually considered as being due to Van der Waals forces or intermolecular forces in the sense of Mulliken s theory. 

Finally, a discussion of possible relationships between the H bond and other bond types must include a reference to the metal chelates. These compounds, treated in detail by Martell and Calvin (1342), involve metal atoms multiply bonded to electron donor atoms in intra-molecular cyclic structures. The metal atom, functioning as an electron acceptor, can be compared to the hydrogen atom in the /n ramolecular H bond. The similarity of the metal and H bond chelates again directs attention to theoretical explanations which relate these bond types. In this instance the charge transfer theory of complex formation advanced by Mulliken (1465) may serve. 

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