A salicylaldiminate/Pd(trifluoroacetate) 2 [SalAld/Pd(tfa) 2 ] initiating system for C1 polymerization of diazoacetate: generation of an active initiator from ordinary reagents with facile procedures

• Published in: Polymer chemistry 2024-03, Vol.15 (11), p.1077-1084
• Main Authors: Shimomoto, Hiroaki, Izumoto, Takaya, Yamashita, Kazuki, Itoh, Tomomichi, Ihara, Eiji
• Format: Article
• Language: English
• Subjects: NMR; Nuclear magnetic resonance; Polymerization; Reagents; Syndiotacticity
• ISSN: 1759-9954; 1759-9962
• DOI: 10.1039/D3PY01426F

Salicylaldiminate (SalAld)-ligated Pd complexes were generated by the reaction of SalAld with Pd(tfa) 2 in THF, and their initiating ability for C1 polymerization of diazoacetate was investigated. When a mixture of a series of SalAlds and Pd(tfa) 2 ([SalAld]/[Pd(tfa) 2 ] = 2 : 1–4 : 1) was employed for the polymerization of ethyl diazoacetate (EDA), polyEDA’ with a high number-average molar mass ( M n , SEC = 20000–35 000) was obtained in moderate yield; the polymer yield became highest (50%) when the polymerization was conducted with a [SalAld]/[Pd(tfa) 2 ] ratio of 4 : 1 at 50 °C for 13 h. NMR analyses indicated that polyEDA’ had a syndiotactic-rich main chain stereo-structure. These results demonstrate that the SalAld/Pd(tfa) 2 system is a new effective initiating system for the C1 polymerization of diazoacetate, which can be generated from a combination of ordinary reagents with facile procedures.