Multisite interaction

Despite the intrinsically nonspecific nature of ion-exchange and reversed-phase/hydrophobic interactions, it is often found that chromatographic techniques based on these interactions can exhibit remarkable resolution this is attributed to the dynamics of multisite interactions being different for proteins having differing surface distributions of hydrophobic and/or ionizable groups. 

Molecular recognition of nucleobases and nucleotides at air-water interfaces (complementary hydrogen bonding and multisite interaction) 98ACR371. 

One of the major ingredient for the understanding of alloy phase stability is the configurational energy. Models have been proposed to represent the configurational energies in terms of effective multisite interactions, in particular effective pair interactions (EPls). 

These two paths are normally associated with different barrier heights introducing, thus, a regio-selectivity in the cycloadditive process. The path associated with the lower energy barrier should be preferred, and the corresponding cycloadduct will be dominant. Now, direct application of HSAB at the local level is not possible here, because it has to be satisfied for both the termini simultaneously. A softness matching criteria, thus, needs to be defined for the multisite interaction that measures the extent of the fulfillment of local HSAB principle. A quantity (A.v) can, thus, be defined to measure the softness matching criteria for the two paths in a least square sense, and the minimum value of this quantity should be preferable [27] ... 

Aime, S., Botta, M., Fedeli, R, et al. (2001) High-relaxivity contrast agents for magnetic resonance imaging based on multisite interactions between a f -cyclodextrin oligomer and suitably functionalized Gdlll chelates. Chemistry - A European Journal, 7, 5261-5269. 

K. Ariga, T. Kunitake, Molecular Recognition at Air-Water and Related Interfaces Complementary Hydrogen Bonding and Multisite Interaction , Acc. Chem. Res, 31(6), 371 (1998)... 

Since, the surface energy curve is obtained for a pseudomorphic alloy on a fixed lattice of the substrate, its behavior can be related directly to the type of so-called effective interactions which are responsible for the ordering of A and B atoms on the surface. That is, if the multisite interactions are small in the system, which is usually the case for metallic alloys on a fixed lattice, the mixing energy can be written in terms of pair potentials between alloy... 

The surface orientation also plays a very important role in the surface alloy formation, since alloying is determined by effective interactions and the corresponding coordination numbers, Zi, which are surface specific. In some cases, especially when the substrate belongs to the IVb-VIIlb group in the periodic table, the multisite interactions may play an important role. In those cases, the surface energy curve will not have the simple parabolic shape presented in Fig. 4 and the alloying behavior may be more complex than described above. To have even a qualitative understanding one may therefore need further input. 

Metal Carbonyl facilitated chemical transformations occur through thermo or photodissociation of one of the carbonyl group from 18-electron transition metal carbonyl, leads to coordinatively unsaturated product, which gives them the capacity to behave as a catalyst for chemical reactions [1], Polynuclear metal carbonyl clusters have their advantages in multisite interaction between the substrate molecules. Transformation of substrate... 

The larger the average pore diameter, the lower the specific surface area and hence the chromatographic retention, A 50-nm pore size silica exhibits a specific surface area of about 50 m /g, about five times lower than that of a 15-nm pore size material. However, due to the multisite interactions of a biopolymer with a bonded silica in HPLC modes such as reversed phase or ion exchanger, the value of the specific surface area is not a critical parameter for the resolution of biopolymers. It has been demonstrated that even the low, entirely external specific surface area of about 1 to 2 m /g of 1- to 2-pm nonporous silica particles is sufficient to retain and to resolve biopolymeric analytes [12]. 

The total energy of a disordered alloy AxBi.x can be described in terms of a convergent series of concentration-independent multisite interactions. For a given spin configuration a the total energy is expressed by ... 

We built an atomistic kinetic model for Al-Zr binary system using ab-initio calculations as well as experimental data. So as to be as realistic as it should be at this atomic scale, this model describes diffusion through vacancy jumps. Thanks to ab-initio calculations we could improve usual thermodynamic descriptions based on pair interactions and incorporate multisite interactions for clusters containing more than two lattice points so as to consider dependence of bonds with their local environment. 

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