Energy molecular probes

If the center of mass of the molecular probe coincides with the Mossbauer nucleus, then the low-energy part of the spectrum monitors exclusively translational modes of the probe molecule thus providing a selective probe for fast translational processes on the lengthscale of several molecular diameters and larger. If, however, the center of mass does not coincide with the Mossbauer nucleus, then hindered rotations, i.e., librations, will contribute to the low-energy DOS. If... 

Molecular Probe Analysis. In an effort to understand how a molecule is seen by either another molecule or by a surface, molecular probes can be moved around a chemical to map out its surface. These probes include anions and cations (point charges) and hard spheres or can be constructed as a combination of these. The empirical potential energy is computed at a variety of points around the test molecule and an energy surface is thus generated. This can be examined graphically and compared as changes are made to the molecule. 

Dale, R., Eisinger, J. and Blumberg, W. (1979). The orientational freedom of molecular probes. The orientation factor in intramolecular energy transfer. Biophys. J. 26, 161-94. 

Dale R. E., Eisinger J. and Blumberg W. E. (1975) The Orientational Freedom of Molecular Probes. The Orientation Factor in Intramolecular Energy Transfer, Biophys. J. 26, 161-194. 

Figure 5. Fluorescence of collagen IV conjugated with Oregon Green 488 (Molecular Probes, Eugene, OR, USA.) spontaneously adsorbed to unmodified polyethylene foils (A) or polyethylene modified with 1014 0+ ions/cm at the energy of 30 keV (B). Collagen was diluted in phosphate-buffered saline to the concentration of 0.02 mg/ml (10 pg/cm ) and incubated with the foils for 24 h at room temperature. For auto fluorescence control.

Immersion of dry samples in liquids of different molecular size This method is designed to take advantage of molecular sieving. The basic data are simply in the form of a curve of the specific energy of immersion versus the molecular size of the immersion liquid. This provides immediate information on the micropore size distribution. For room-temperature experiments one can use the liquids listed in Table 8.1, which are well suited for the study of carbons. Because of the various ways of expressing the critical dimension of a molecular probe or its molecular size , one must be careful to use a consistent set of data (hence the two separate lists in Table 8.1). Again, one can process the microcalori-metric data to compare either the micropore volumes accessible to the various molecules (see Stoeckli et a ., 1996), or the micropore surface areas, as illustrated in Figure 8.5. 

These are molecular interaction fields obtained by calculating electrostatic interaction energy between probe and target in each grid point. Besides the molecular electrostatic potential (M E P), the most common energy function for electrostatic interactions is the Coulomb potential energy function defined as... 

C.T. Rettner and D.J. Auerbach. Probing the Dynamics of Gas-Surface Interactions with High Energy Molecular Beams. Comments At. Mol. Phys. 20 153 (1989). 

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