<div><p>The binuclear radical complex [N-hydrogenpyridinium]<sub>2</sub>[Ni(tdas)<sub>2</sub>]<sub>2</sub> (tdas = 1,2,5-thiazole-3,4-dithiolate) has been prepared and its crystal structure determined by X-ray crystallography. In the binuclear radical complex, the two nickel ions assume a distorted pyramidal geometry and are bridged by two sulfurs of different tdas anionic ligands. ESR spectra and the theoretical calculations reveal a very strong antiferromagnetic interaction in the binuclear radical complex, leading to diamagnetic crystals. The theoretical calculations also reveal a very weak antiferromagnetic interaction between adjacent radical complexes. This study is the first to report the magnetism of a binuclear radical nickel complex with tdas as ligand.</p></div
