Side-bridged cyclam transition metal complexes bearing a phenolic ether or a phenolate pendent arm

Mewis, Ryan E.; Archibald, Stephen J.

Abstract

Side-bridged cyclam transition metal complexes (M = Ni(II), Cu(II) and Zn(II)) bearing a phenolic ether or phenolate pendent arm have been synthesised. For [NiL1]+ and [CuL1]+, evidence for a phenoxyl radical was obtained (quasi reversible peak at +0.74 V and +0.48 V respectively), as well as oxidation of OH, due to protonation of the phenolate, at ∼+1.24 V. The phenoxyl radical in [Ni(L1)]2+ is harder to oxidise by 0.26 V compared with the corresponding Cu(II) complex. UV-Vis data for [Ni(L1)]2+ suggests that the Ni(II) ion may be 4 or 6 coordinate whereas the Cu(II) ion in [Cu(L1)]2+ is five coordinate. The Ni(II) ion in the crystal structure of [Ni(L2)][(ClO4)2] possesses a distorted square-planar geometry in which the phenolic ether pendent arm is not involved in the coordination sphere. The cyclam ligand in this complex adopts a trans-II configuration.

Citation

Mewis, R. E., & Archibald, S. J. (2019). Side-bridged cyclam transition metal complexes bearing a phenolic ether or a phenolate pendent arm. Polyhedron, 171, 578-589. https://doi.org/10.1016/j.poly.2019.08.003

• Journal Article Type: Article
• Acceptance Date: Aug 1, 2019
• Online Publication Date: Aug 10, 2019
• Publication Date: Oct 1, 2019
• Deposit Date: Aug 17, 2019
• Publicly Available Date: Aug 11, 2020
• Journal: Polyhedron
• Print ISSN: 0277-5387
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 171
• Pages: 578-589
• DOI: https://doi.org/10.1016/j.poly.2019.08.003
• Keywords: Macrocyclic ligands; Azamacrocycles; Cyclam; Bioinorganic; Coordination chemistry
• Public URL: https://hull-repository.worktribe.com/output/2444111
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0277538719305285?via%3Dihub
• Additional Information: ©2019, Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/