Tuning a robust system: N,O Zinc Guanidine Catalysts for the ROP of Lactide

Pascal M Schäfer, Paul McKeown, Martin Fuchs, Ruth Rittinghaus, Alina Hermann, Johanna Henkel, Sebastian Seidl, Christopher Roitzheim, Agnieszka Ksiazkiewicz, Alexander Hoffmann, Andrij Pich, Matthew Jones, Sonja Herres-Pawlis

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

Non-toxic, highly-active and robust complexes are the holy grail as ideal green catalysts for the polymerisation of biobased and biodegrable polylactide. Four new zinc guanidine complexes [ZnCl2(TMG4NMe2asme)], [ZnCl2(TMG5Clasme)], [ZnCl2(TMG5Measme)] and [ZnCl2(TMG5NMe2asme)] with different electron-donating and electron-withdrawing groups on aromatic backbone of the ligand have been synthesised. Ligands are derived from low-cost commercially available compounds and have been converted in a three- or four-step synthesis into the desired ligand in good yields. The compounds have been fully characterised and tested in the ROP of rac-LA in the melt under industrially relevant conditions. The complexes are based on the recently published structure [ZnCl2(TMGasme)] which has shown high activity in the polymerisation of lactide at 150 °C. Different substituents in the para-position to the guanidine moiety significantly increase the polymerisation rate whereas positioning substituents in meta-position causes no change in the reaction rate. With molecular weights over 71 000 g mol-1, the best catalyst produces polymer for several industrial applications and its polymerisation rate approaches the one of Sn(Oct)2. The robust systems are able to polymerise non-purified lactide. The initiation of the polymerisation is suggested to occur by impurities in the monomer.
Original languageEnglish
Pages (from-to)6071-6082
Number of pages12
JournalDalton Transactions
Volume48
Issue number18
Early online date29 Jan 2019
DOIs
Publication statusPublished - 14 May 2019

ASJC Scopus subject areas

  • Inorganic Chemistry

Cite this

Schäfer, P. M., McKeown, P., Fuchs, M., Rittinghaus, R., Hermann, A., Henkel, J., ... Herres-Pawlis, S. (2019). Tuning a robust system: N,O Zinc Guanidine Catalysts for the ROP of Lactide. Dalton Transactions , 48(18), 6071-6082. https://doi.org/10.1039/C8DT04938F

Tuning a robust system: N,O Zinc Guanidine Catalysts for the ROP of Lactide. / Schäfer, Pascal M; McKeown, Paul; Fuchs, Martin ; Rittinghaus, Ruth ; Hermann, Alina ; Henkel, Johanna; Seidl, Sebastian; Roitzheim, Christopher; Ksiazkiewicz, Agnieszka; Hoffmann, Alexander; Pich, Andrij; Jones, Matthew; Herres-Pawlis, Sonja.

In: Dalton Transactions , Vol. 48, No. 18, 14.05.2019, p. 6071-6082.

Research output: Contribution to journalArticle

Schäfer, PM, McKeown, P, Fuchs, M, Rittinghaus, R, Hermann, A, Henkel, J, Seidl, S, Roitzheim, C, Ksiazkiewicz, A, Hoffmann, A, Pich, A, Jones, M & Herres-Pawlis, S 2019, 'Tuning a robust system: N,O Zinc Guanidine Catalysts for the ROP of Lactide', Dalton Transactions , vol. 48, no. 18, pp. 6071-6082. https://doi.org/10.1039/C8DT04938F
Schäfer PM, McKeown P, Fuchs M, Rittinghaus R, Hermann A, Henkel J et al. Tuning a robust system: N,O Zinc Guanidine Catalysts for the ROP of Lactide. Dalton Transactions . 2019 May 14;48(18):6071-6082. https://doi.org/10.1039/C8DT04938F
Schäfer, Pascal M ; McKeown, Paul ; Fuchs, Martin ; Rittinghaus, Ruth ; Hermann, Alina ; Henkel, Johanna ; Seidl, Sebastian ; Roitzheim, Christopher ; Ksiazkiewicz, Agnieszka ; Hoffmann, Alexander ; Pich, Andrij ; Jones, Matthew ; Herres-Pawlis, Sonja. / Tuning a robust system: N,O Zinc Guanidine Catalysts for the ROP of Lactide. In: Dalton Transactions . 2019 ; Vol. 48, No. 18. pp. 6071-6082.
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