Ferromagnetic Exchange Coupling in Ni(II) Complexes with a Coordinated Boron‐Oxamido Radical: A Result of Spin State Transition

Abstract

Comprehensive SummaryA Ni(II) coordination complex 1 with a novel boron‐oxamido radical ligand was synthesized and isolated. Reactions of 1 with N,N‐dimethyl‐4‐pyridinamine (DMAP) and 4,4’‐bpy resulted in 2 and 3, respectively, accompanied by the spin state transition from S = 1/2 to S = 3/2. Both 2 and 3 were isolated as stable crystals and characterized to feature an S = 3/2 spin state, with the S = 1 Ni(II) atoms ferromagnetically coupled with the ligand‐centred radicals, by SQUID measurement and EPR spectroscopy. Complex 3 represents the first example of one‐dimensional magnetic chain constructed by S = 3/2 Ni(II)‐radical units.