Intra-molecular transfer

Inter and intra molecular transfer leading to products as in the thermal reaction. 

The first steps in the proposed mechanism are essentially the same as those established for monometal Rh/PPhj catalysts, except that the proposed addition of H2 oxidises two metal centres. In monometal systems, the final steps are the addition of H2 to a rhodium(i) to produce a rhodium(iii) dihydride species that can then eliminate aldehyde product. The ruthenium-rhodium intermediate avoids this problem by having a proximate Ru-H moiety, which can intra-molecularly transfer a hydride to facilitate the aldehyde elimination. Thus the final steps of the mechanism are H and CO bridge formation between the... 

It was long believed that cationic polymerization was an unsatisfactory route to synthesize well-defined functional polymers because of inter- or intra-molecular transfer or rearrangement However, in recent years, several monomers have exhibited sufficient control of initiation, propagation and termination to allow the synthesis of functional polymers. Tetrahydrofuran (THF) has been cationically polymerized using the difunctional initiator triflic anhydride (Scheme 4). ... 

With the above system, the rate constant of photo-induced electron transfer is 2.7X10 sec This intra-molecular transfer is expected to occur at the minimum separation between the limits of the aromatic ring and the C=C(CN)2 group, which is about 6.5 A. 

Straub J E and Berne B J 1986 Energy diffusion in many dimensional Markovian systems the consequences of the competition between inter- and intra-molecular vibrational energy transfer J. Chem. Phys. 85 2999 Straub J E, Borkovec M and Berne B J 1987 Numerical simulation of rate constants for a two degree of freedom system in the weak collision limit J. Chem. Phys. 86 4296... 

A different mechanism operates in the wheat germ enzyme. 2,3-Bisphosphoglycerate is not a cofactor. Instead, the enzyme carries out intra-molecular phosphoryl group transfer (Figure 19.25). The C-3 phosphate is transferred to an active-site residue and then to the C-2 position of the original substrate molecule to form the product, 2-phosphoglycerate. 

Berlin YA, Ratner MA (2005) Intra-molecular electron transfer and electric conductance via sequential hopping unified theoretical description. Radiat Phys Chem 74 124—131... 

The reaction temperature is above the critical temperature of ethylene so that the ethylene is in gas phase. High pressures are needed for propagation reaction. Only about 6-25 per cent of ethylene is polymerised. Rest of monomer is recycled. Extensive chain transfer reactions takes place during polymerisation to yield a branched chain polyethylene. In addition to long branches, it also contains a large number of short branches of upto 5 carbon atoms produced by intra-molecular chain transfer reactions. A typical molecule of Low density polyethylene contains a short branch for about every 50 carbon atoms and one or two long branches per molecule. 

It is supposed that hydrogen bonds between halogen atoms of the superacid and the a-hydrogens of the oxime in the Lewis acid-oxime complex can play a role in the hydride transfer either by inter- or by intra-molecular processes. 

In (1), Hq yields the total energy of system in which the molecules and the lattice are excited, yet there are no interactions between molecules and the lattice. The transfer of an electron from site m to site n is given by //j. Polaronic effects, i.e., effects due to the interaction of the electronic excitation and the lattice, are given by H2 and H. hi H2, the energy of the site is reduced by the interaction with the lattice vibration. In H, the lattice vibration alters the transition probability amplitude from site m to n. The term lattice vibration may refer to inter-molecular or intra-molecular vibrations. Static disorder effects are considered in H4, which describes the changes to the site energy or transition probabihty amplitude by variations in the structure of the molecular sohd. 

As a hydride ion, that is with the pair of electrons from the C-H bond. This type of reaction is called a hydride transfer. You may have noticed that the transfer was done intra-molecularly within a six-membered ring and therefore has a six-membered transition state. Draw it. 

Because phenyl and vinyl radicals are highly reactive, side reactions like inter- and intra-molecular hydrogen transfer and addition to the solvent are of greater concern. 

Thus, the hydrazide or its azo analogue not only plays a key-role in the catalytic cycle as a hydrogen acceptor and a reductant for the copper catalyst, but it also acts as an acyl transfer reagent generating competitively the undesired mixed carbonate 20. This by-product presumably originates from the inter- or intra-molecular nucleophilic attack of the alcohol on either the copper-hydrazide or azo complexes 13 or 18 respectively, resulting ultimately in the deactivation of the catalyst. To minimize this undesired trans-acylation reaction, steri-cally demanding azo-derivatives were tested (Fig. 7). Whilst di-isopropyl... 

---