A comparison of the PVCILO calculated stabilization energies of the DA complexes ofN-phenylmaleimide and 4-phenyl-1,2,4-triazoline-3,5-dione with methyl vinyl ether
✍ Scribed by George B. Butler; Choon Ho Do; Michael C. Zerner
- Publisher
- Springer
- Year
- 1995
- Tongue
- English
- Weight
- 297 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0170-0839
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✦ Synopsis
A PVCILO method has been used to compare the stabilization energies of the electron donor electron acceptor complexes between methyl vinyl ether as donor and the enophiles, 4phenyl 1-1,2,4-triazoline-3,5-dione (1) and N-phenylmaleimide (2), respectively, as acceptor. A stabilization energry difference in favor of the more reactive 1 was obtained, which is being interpreted as an explanation for the enhanced rate of reaction of I vs 2, often by factors >104.
Discussion and Results
4-Substituted triazolinediones are exceptionally strong electron acceptors and are among the most powerful enophiles and dienophiles known. They react with vinyl ethers and esters, styrenes, B-diketones, and alkenes. They have also been used as low-temperature modifiers of diene polymers to produce products which vary widely from thermoplastic elastomers at low conversion to rigid, amorphous polymers with high softening points at high conversion 1,2. The modified polymers possess an acidic proton, as they contain the 1,4-disubstituted-l,2,4triazolidine-3,5-dione function. For example, the product of the reaction of propene with 1, N"~-~N