Versatile synthesis of chiral 6-oxoverdazyl radical ligands - new building blocks for multifunctional molecule-based magnets.

['Solea AB', 'Wohlhauser T', 'Abbasi P', 'Mongbanziama Y', 'Crochet A', 'Fromm KM', 'Novitchi G', 'Train C', 'Pilkington M', 'Mamula O']
Dalton Trans. 2018 Mar 13. doi: 10.1039/c8dt00840j. [Epub ahead of print]

Author information
['Department of Chemistry, University of Applied Sciences Western Switzerland (HES-SO), HEIA-FR, Pérolles 80, CH-1700 Fribourg, Switzerland. olimpia.mamulasteiner@hefr.ch.', 'Department of Chemistry, Brock University, 1812 Sir Isaac Brock Way, St Catharines, Ontario L2S3A1, Canada. mpilkington@brocku.ca.', 'Department of Chemistry, University of Fribourg, Ch. du Musée 9, CH-1700 Fribourg, Switzerland.', 'Laboratoire National des Champs Magnétiques Intenses, UPR CNRS 3228, 25, rue des Martyrs, B.P. 166, 38042 Grenoble, France.']

Abstract
['A versatile synthetic methodology to access the first family of chiral verdazyl N,N'-chelate ligands is described and exemplified by N,N'-dimethyl-, N,N'-di-isopropyl- and N,N'-diphenyl oxoverdazyls bearing two isomers of the pinene-pyridine functional group. Their physical properties were probed by X-band EPR spectroscopy, cyclic voltammetry and DFT calculations. Preliminary reactivity studies show they can act as N,N'-chelate ligands affording a chiral 1u2009:u20091 complex (3b) with CuCl2, which was characterized by single-crystal X-ray diffraction. Variable temperature EPR studies on (3b) confirm the presence of antiferromagnetic interactions between the spins of the Cu(ii) ion and the verdazyl radical.']