Organoaluminium complexes derived from Anilines or Schiff bases for ring opening polymerization of epsilon-caprolactone, delta-valerolactone and rac-lactide

Mo, Shangyan; Prior, Timothy J.; Al-Khafaj, Yahya; Zhao, K.-Q.; Wang, X.; Elsegood, Mark R.J.; Elsegood, Mark R. J.; Wang, Xue; Zhao, Ke-Qing; Al-Khafaji, Yahya; Mo, Shanyan; Prior, Timothy; Elsegood, Mark; Redshaw, Carl

Abstract

Reaction of R¹R²CHN=CH(3,5-tBu₂C₆H₂-OH-2) (R¹ = R² = Me L¹H; R¹ = Me, R² = Ph L²H; R¹ = R2 = Ph L³H) with one equivalent of R³3Al (R³ = Me, Et) afforded [(L¹-³)AlR³₂] (L¹, R³ = Me 1, R³ = Et 2; L², R³ = Me 3, R³ = Et 4; L³ R³ = Me 5, R³ = Et 6); complex 1 has been previously reported. Use of the N,O-ligand derived from 2,2/-diphenylglycine afforded either 5 or a by-product [Ph₂NCH₂(3,5-tBu₂C₆H₂-O-2)AlMe₂] (7). The known Schiff base complex [2-Ph₂PC₆H4CH₂(3,5-tBu₂C₃H₂-O-2)AlMe₂] (8) and the product of the reaction of 2-diphenylphosphinoaniline 1-NH₂,2-PPh₂C₆H4 with Me3Al, namely {Ph₂PC₆H4N[(Me₂Al)₂mu-Me](mu-Me₂Al)} (9) were also isolated. For structural and catalytic comparisons, complexes resulting from interaction of Me₃Al with diphenylamine or benzhydrylamine, namely {Ph₂N[(Me₂Al)2mu-Me]} (10) and [Ph₂CHNH(mu-Me₂Al)]₂·MeCN (11), were prepared. The molecular structures of the Schiff pro-ligands derived from Ph₂CHNH₂ and 2,2/-Ph2C(CO₂H)(NH₂), together with complexes 5, 7 and 9 - 11·MeCN were determined. All complexes have been screened for their ability to ring opening polymerization (ROP) epsilon-caprolactone, delta-valerolactone or rac-lactide, in the presence of benzyl alcohol, with or without solvent present. The co-polymerization of epsilon-caprolactone with rac-lactide has also been studied.

Citation

Mo, S., Prior, T. J., Al-Khafaj, Y., Zhao, K.-Q., Wang, X., Elsegood, M. R., Elsegood, M. R. J., Wang, X., Zhao, K.-Q., Al-Khafaji, Y., Mo, S., Prior, T., Elsegood, M., & Redshaw, C. (2017). Organoaluminium complexes derived from Anilines or Schiff bases for ring opening polymerization of epsilon-caprolactone, delta-valerolactone and rac-lactide. European Journal of Inorganic Chemistry, 2017(13), 1951-1965. https://doi.org/10.1002/ejic.201601415

• Journal Article Type: Article
• Acceptance Date: Jan 20, 2017
• Online Publication Date: Apr 5, 2017
• Publication Date: Apr 3, 2017
• Deposit Date: Jan 24, 2017
• Publicly Available Date: Jan 23, 2018
• Journal: European journal of inorganic chemistry
• Print ISSN: 1434-1948
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 2017
• Issue: 13
• Pages: 1951-1965
• DOI: https://doi.org/10.1002/ejic.201601415
• Keywords: Aluminium; Anilines; Schiff-base; Molecular structures; Ring opening polymerization
• Public URL: https://hull-repository.worktribe.com/output/447475
• Publisher URL: http://onlinelibrary.wiley.com/wol1/doi/10.1002/ejic.201601415/abstract
• Additional Information: Authors' accepted manuscript of article: Wang, X., Zhao, K.-Q., Al-Khafaji, Y., Mo, S., Prior, T. J., Elsegood, M. R. J. and Redshaw, C. (2017), Organoaluminium Complexes Derived from Anilines or Schiff Bases for the Ring-Opening Polymerization of ε-Caprolactone, δ-Valerolactone and rac-Lactide. Eur. J. Inorg. Chem., 2017: 1951–1965. doi:10.1002/ejic.201601415
• Contract Date: Jan 23, 2018