Abstract: | The purple colored coordination polymer [1 Cu]n was obtained from 2,5‐bis(pyrazol‐1‐yl)‐1,4‐dihydroxybenzene and CuBr2 in aqueous ammonia. The crystal structure of [1 Cu]n was determined from high resolution X‐ray powder diffraction data using the method of simulated annealing. In the solid state, [1 Cu]n features largely independent linear chains, all of them being oriented parallel to the c‐axis of the crystal. The Cu ions are coordinated in a square‐planar fashion by two nitrogen atoms and two anionic oxygen donors. Magnetic susceptibility and magnetization measurements indicate the Cu ions in [1 Cu]n to be antiferromagnetically coupled with a coupling constant of about 20 K. |