Catalysis and Mechanism

K. Kootu, Oiganametallic Mechanisms and Catalysis, Aosdemio Press, Nev/ York, 197S, pp. 3S1-3S6. 

There is still a great deal of effort being made on the study of the mechanisms and catalysis of lactide, glycolide, and lactone polymerizations,367,379-383 and many reviews have been published on this topics.365,384 386 Since it is basically a chain-growth, rather titan a step-growth, process, it is beyond the scope of this book and will not be extensively discussed here. Nevertheless, it is worth mentioning that very close resemblances exist between the mechanisms... 

Dedieu A (1999) Theoretical Treatment of Organometallic Reaction Mechanisms and Catalysis. 4 69-107... 

J. K. Kochi, Organometallic Mechanisms and Catalysis, Academic Press, New York, 1979. 

ENZYME MECHANISM AND CATALYSIS OF HISTONE LYSINE METHYLATION [49,50]... 

Nucleophilic substitution, in phosphate esters, mechanism and catalysis of, 25,99 Nucleophilic substitution, single electron transfer and, 26, 1 Nucleophilic vinylic substitution, 7,1... 

Partitioning of carbocations between addition of nucleophiles and deprotonation, 35, 67 Perchloro-organic chemistry structure, spectroscopy and reaction pathways, 25, 267 Permutational isomerization of pentavalent phosphorus compounds, 9, 25 Phase-transfer catalysis by quaternary ammonium salts, 15, 267 Phosphate esters, mechanism and catalysis of nucleophilic substitution in, 25, 99 Phosphorus compounds, pentavalent, turnstile rearrangement and pseudoration in permutational isomerization, 9, 25... 

Kochi, J.K. "Organometallie Mechanisms and Catalysis" Academic Press New York, 1974. 

Kochi, J.K. "Organometallic Mechanisms and Catalysis," Academic Press, NY, 1978, Chap. 11. 

Kobayashi, H., Marumo, F. and Saito, Y. (1971). Acta Crystallogr., Sect. B 27, 373 Kochi, J. K. (1978). Organometallic Mechanisms and Catalysis. Academic Press, New York... 

Like the monomers, the co-monomers are diols or diacids, and according to their functional groups, their reactions with TPA and EG follow the principal mechanisms outlined above. Very few data have been published on reactions with co-monomers, and it may be assumed that the same mechanisms and catalysis concepts should hold. Nevertheless, it has been observed that co-monomers influence the overall reaction rates significantly. In a typical batch process, the polycondensation time needed to prepare a polymer with an IV of 0.64 dL/g increases by about one third with co-monomer IPA and by about two thirds with co-monomer CHDM, in comparison to homo-PET. This may in part be due to the differing correlations between Pn and IV, but additionally a reduced reactivity due to steric and electronic effects or the influence of co-monomers on the mobility of functional groups seems probable. 

---