A Three-Dimensional Coordination Framework with a Ferromagnetic Coupled Ni(II)-CrO<sub>4</sub> Layer: Synthesis, Structure, and Magnetic Studies

oleh: Hsu-Yen Tang, Gene-Hsiang Lee, Kwai-Kong Ng, Chen-I Yang

Format: Article
Diterbitkan: MDPI AG 2022-04-01

Deskripsi

We report herein on the crystal structure and magnetic studies of a three-dimensional (3D) Ni(II)-chromate coordination polymer, [Ni(CrO<sub>4</sub>)(bpym)(H<sub>2</sub>O)]<i><sub>n</sub></i> (<b>1</b>; bpym = 5,5′-bipyrimidin), prepared by self-assembly of Ni(II) and chromate ions with a multi-<i>N</i> donor auxiliary ligands, bpym, through hydrothermal processes. The structure of <b>1</b> is composed of Ni(II)-CrO<sub>4</sub> layers with [Ni<sub>3</sub>(<i>μ</i><sub>3</sub>-CrO<sub>4</sub>)] triangular motifs, in which the Ni(II) centers are bridged by <i>O</i>′:<i>O</i>′:<i>O</i>′:<i>μ</i><sub>3</sub>-CrO<sub>4</sub><sup>2−</sup> anions, and the resulting layers are further connected by twisted <i>trans</i>-<i>μ</i><sub>2</sub>-<i>N</i>,<i>N</i>′-bpym auxiliary ligands to form a 3D pillar-layered network with an <b>hms</b> topology. The magnetic properties of compound <b>1</b> were illustrated by variable field and temperature magnetic susceptibility measurements. The findings reveal that compound <b>1</b> shows intralayer ferromagnetic interactions within Ni(II)-CrO<sub>4</sub> layers, and furthers the 3D antiferromagnetic ordering in the resulting of interlayer antiferromagnetic couplings with a Néel temperature (<i>T</i><sub>N</sub>) of 5.6 K. In addition, compound <b>1</b> shows the field-induced metamagnetic behavior at temperature below the <i>T</i><sub>N</sub>.