Molybdenum complexes derived from the oxydianiline [(2-NH₂C₆H₄)₂O] : synthesis, characterization and ε-caprolactone ROP capability

Yang, Wenxue; Zhao, Ke-Qing; Redshaw, Carl; Elsegood, Mark R. J.

Abstract

The reaction of Na₂MoO₄ with 2,2′-oxydianiline (2-aminophenylether), (2-NH₂C₆H₄)₂O, LH₄, in DME (DME = 1,2-dimethoxyethane) in the presence of Et₃N and Me₃SiCl afforded either the bis(imido) molybdenum(VI) complex {Mo(L)Cl₂(DME)} (1), where L = (2-NC₆H₄)₂O, or the molybdenum(V) salt [Mo(L′)Cl₄][Et₃NH] (2), where L′ = [(2-NH₂C₆H₄)(2-NC₆H₄)O], depending on the work-up method employed. The same diamine reacted with in situ [Mo(NtBu)₂Cl₂(DME)] afforded a tetra-nuclear complex [Mo₄Cl₃(NtBu)₃(OSiMe₃)(μ₄-O)(L)₂(L′)₂]·2MeCN (3·2MeCN). The crystal structures of 1, 2 and 3·2MeCN have been determined. The structure of the bis(imido) complex 1 contains two unique molecules paired up via weak π-stacking, whereas the structure of 2 contains a chelating amine/imido ligand, and is made up of discrete units of two cations and two anions which are interacting via H-bonding. The tetra-nuclear structure 3 contains four different types of distorted octahedral molybdenum centre, and a bent Me₃SiO group thought to originate from the precursor synthesis. Complexes 1–3 have been screened for their ability to ring open polymerize (ROP) ε-caprolactone. For 1 and 3 (not 2), conversion rates were good (>90%) at high temperatures (100 °C) over 6–24 h, and the polymerization proceeded in a living manner.

Citation

Yang, W., Zhao, K., Redshaw, C., & Elsegood, M. R. J. (2015). Molybdenum complexes derived from the oxydianiline [(2-NH₂C₆H₄)₂O] : synthesis, characterization and ε-caprolactone ROP capability. Dalton Transactions : an international journal of inorganic chemistry, 44(29), 13133-13140. https://doi.org/10.1039/c5dt01799h

• Journal Article Type: Article
• Acceptance Date: Jun 11, 2015
• Online Publication Date: Jun 18, 2015
• Publication Date: Aug 7, 2015
• Deposit Date: Jul 17, 2015
• Publicly Available Date: Jul 17, 2015
• Journal: Dalton transactions
• Print ISSN: 1477-9226
• Electronic ISSN: 1477-9234
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 44
• Issue: 29
• Pages: 13133-13140
• DOI: https://doi.org/10.1039/c5dt01799h
• Keywords: Molybdenum complexes , 2-NH₂C₆H₄)₂O, ε-caprolactone ROP capability, Ring opening polymerization
• Public URL: https://hull-repository.worktribe.com/output/376531
• Publisher URL: http://pubs.rsc.org/en/Content/ArticleLanding/2015/DT/C5DT01799H#!divAbstract
• Additional Information: Authors' accepted manuscript of article published in: Dalton transactions, 2015, v.44, issue 29 at http://pubs.rsc.org/en/Content/ArticleLanding/2015/DT/C5DT01799H#!divAbstract