Intramolecular energy change

Fig. 10. Internal energy changes as a function of deformation for oriented LDPE (I) and stress softened thermo-elastoplastic polyurethanes with 50% (2) and 42 % (3) hard phase content and polyether-polyester block copolymer with 48% hard phase content (4). The dotted curves 1 and 2 represent intramolecular energy changes for the corresponding polymers119 ...

Intramolecular energy change of bonded atoms Intramolecular energy change of non-bonded atoms ... 

Intermolecular energy change Intramolecular energy change of other chains ... 

The first contribution concerns the change in the intermolecular interaction energy experienced by the stretched sequence on a transfer into the melt and the second part gives the intramolecular energy change associated with the... 

Kelley and co-workers [70, 71] measured the dynamics of the excited-state intramolecular proton transfer in 3-hydroxyflavone and a series of its derivatives as a function of solvent (Scheme 2.9). The energy changes associated with the processes examined are of the order of 3 kcal/mol or less. The model they employed in the analysis of the reaction dynamics was based upon a tunneling reaction path. Interestingly, they find little or no deuterium kinetic isotope effect, which would appear to be inconsistent with tunneling theories. For 3-hydroxy-flavone, they suggest the lack of an isotope effect is due to a very large... 

AG° is the standard free energy change for intramolecular electron transfer. Both k i and K are contributary factors to a dependence of k on r, and (5.73) can be written... 

These expressions demonstrate that the change of entropy and internal energy on deformation under these conditions is both intra- and intermolecular in origin. Intramolecular (conformational) changes, which are independent of deformation, are characterized by the temperature coefficient of the unperturbed dimensions of chains d In intermolecular changes are characterized by the thermal expansivity a and are strongly dependent on deformation. The difference between the thermodynamic values under P, T = const, and V, T = const, is vefy important at small deformations since at X - 1 2aT/(/,2 + X — 2) tends to infinity. 

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