Phase-transfer reactions catalyzed by phosphonium salts attached to polystyrene resins by spacer chains
✍ Scribed by Tomoi, Masao ;Ogawa, Eiji ;Hosokama, Yasunori ;Kakiuchi, Hiroshi
- Book ID
- 105334088
- Publisher
- John Wiley and Sons
- Year
- 1982
- Weight
- 444 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0360-6376
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✦ Synopsis
Abstract
The rate of reaction of 1‐halooctanes with aqueous sodium cyanide catalyzed by phosphonium salts attached to insoluble polystyrene resins by tetramethylene or heptamethylene spacers was studied as a function of catalyst particle size, degree of polymer crosslinking, percentage of ring substitution, and temperature. Rates of reaction of 1‐bromooctane with 17–38% ring‐substituted catalysts increased as spacer‐chain length increased. Rates of reaction of 1‐bromooctane decreased, whether the percentage of ring substitution increased or decreased from 17–19%. Rates of reaction of 1‐chlorooctane increased with increasing spacer‐chain length and decreasing percentage of ring substitution. Apparent activation energy for the reaction of 1‐bromooctane with 9% ring‐substituted, spacer‐modified catalysts was 9–10 kcal/mol and 13 kcal/mol with 17–19% ring‐substituted catalysts. The hydrophilicity of catalysts decreased with increasing spacer‐chain length and decreasing percentage of ring substitution. The mechanisms of reaction were discussed in terms of intrinsic reactivity and intraparticle diffusion limitations on the reaction rates.
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