Mulliken charge-transfer formalism

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... 

Consideration of the spectral and thermodynamic properties of arene CT complexes thus indicates that they are reasonably described within the framework of recent developments of the Mulliken formalism, in the case of both weak and strong complexes in the highly en-dergonic and nearly isergonic regions. Accordingly, let us now consider the structural consequences attendant upon charge transfer from the donor to the acceptor in such complexes. 

Using the Mulliken formalism, Hush [29] showed that the electronic coupling element is related to the intensity of the charge transfer transition by ... 

In the case of a mixture of gases each species has its own value of the Mulliken electronegativity, and therefore its own value of the charge transfer coefficient 5. Clearly, for a matrix of a given WF some gases may act as electron donors, some as electron acceptors and some may be inert. For a matrix of a different value of WF these proportions will be different. In a formal analogy with the Nikolskij-Eisenmann equation governing the selectivity of ion-selective electrodes we can formulate the response of the WF sensor in a mixture as... 

Combination of Mulliken s formalism with the Marcus quadratic representation [10] of the initial and final (diabatic) states allows the energy profile of the ET reaction coordinate to be constructed. As illustrated in Figure 8, an increase in Hab results in (i) a lowering of the ET barrier, (ii) a stabilization of the precursor and successor (CT) complexes, and (iii) a shift of their positions along the reaction coordinate (i.e. the charge is partially transferred from the... 

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