Asymmetric Ring Opening in a Tetrazine‐Based Ligand Affords a Tetranuclear Opto‐Magnetic Ytterbium Complex. Issue 7 (16th December 2020)

• Record Type: Journal Article
• Authors: Richardson, Paul; Marin, Riccardo; Zhang, Yixin; Gabidullin, Bulat; Ovens, Jeffrey; Moilanen, Jani O.; Murugesu, Muralee
• Is Part Of: Chemistry. Volume 27:Issue 7(2021)
• Page Start: 2361
• Page End: 2370
• Publication Date: 2020-12-16
• Subjects: opto-magnetic properties -- photoluminescence -- single-molecule magnets -- tetrazine -- ytterbium; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202003556
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: We report the formation of a tetranuclear lanthanide cluster, [Yb4 (bpzch)2 (fod)10 ] (1 ), which occurs from a serendipitous ring opening of the functionalised tetrazine bridging ligand, bpztz (3, 6‐dipyrazin‐2‐yl‐1, 2, 4, 5‐tetrazine) upon reacting with Yb(fod)3 (fod − =6, 6, 7, 7, 8, 8, 8‐heptafluoro‐2, 2‐dimethyl‐3, 5‐octandionate). Compound 1 was structurally elucidated via single‐crystal X‐ray crystallography and subsequently magnetically and spectroscopically characterised to analyse its magnetisation dynamics and its luminescence behaviour. Computational studies validate the observed MJ energy levels attained by spectroscopy and provides a clearer picture of the slow relaxation of the magnetisation dynamics and relaxation pathways. These studies demonstrate that 1 acts as a single‐molecule magnet (SMM) under an applied magnetic field in which the relaxation occurs via a combination of Raman, direct, and quantum tunnelling processes, a behaviour further rationalised analysing the luminescent properties. This marks the first lanthanide‐containing molecule that forms by means of an asymmetric tetrazine decomposition. Abstract : Chemistry is like a box of chocolates : The combination of ytterbium(III), cobaltocene, and 3, 6‐dipyrazin‐2‐yl‐1, 2, 4, 5‐tetrazine (bpztz) leads to an unexpected asymmetric ring opening of the central tetrazine, yielding the first lanthanide‐based compound with such an asymmetric opening. A comparison of magnetic and luminescence data with theoretical calculations allowed an accurate and in‐depth comparison of the energy levels of the compound.