The title compound showed a unique low-dimensional array with S = 1 molecules. The intermolecular antiferromagnetic coupling and intramolecular ferromagnetic coupling are simultaneously present, and accordingly, the S = 1/2 state appeared at 230-350 K between the diamagnetic phase and the paramagnetic S = 1 phase. The solid solid phase transition occurred in a single-crystal-to-single-crystal manner. The corresponding 3'-methoxy derivative is also presented for comparison.