Syntheses, Structure, and Magnetic Properties of New Types of Cu(II), Co(II), and Mn(II) Organophosphonate Materials:  Three-Dimensional Frameworks and a One-Dimensional Chain Motif

The hydrothermal syntheses, structures, and magnetic properties of the Cu(II), Co(II), and Mn(II) complexes with organophosphonic acid H<sub>2</sub>O<sub>3</sub>PCH<sub>2</sub>NH<sub>2</sub><sup>+</sup>CH<sub>2</sub>PO<sub>3</sub>H<sup>-</sup> are reported. Compound Cu<sub>3</sub>[NH<sub>2</sub>(CH<sub>2</sub>PO<sub>3</sub>)<sub>2</sub>]<sub>2</sub> (<b>1</b>) crystallizes in the orthorhombic space group <i>Pbca</i>, with unit cell parameters <i>a</i> = 9.4430(10) Å, <i>b</i> = 9.3681(10) Å, <i>c</i> = 16.0755(17) Å, <i>V</i> = 1422.1(3) Å<sup>3</sup>, and <i>Z</i> = 4. The X-ray crystallographic determination reveals copper ions in two different coordination environments that are bridged by one terminal oxygen atom to form a three-dimensional framework of corner-sharing layers. Antiferromagnetic coupling between the two types of Cu units in <b>1</b> was observed at 15 K, followed by ferromagnetic ordering at 9 K. Compound Co<sub>3</sub>[NH<sub>2</sub>(CH<sub>2</sub>PO<sub>3</sub>)<sub>2</sub>]<sub>2</sub> (<b>2</b>) crystallizes in the orthorhombic space group <i>P</i>2<sub>1</sub>2<sub>1</sub>2 with unit cell parameters <i>a</i> = 10.7346(8) Å, <i>b</i> = 13.3704(10) Å, <i>c</i> = 5.3699(4) Å, <i>V</i> = 770.72(10) Å<sup>3</sup>, and <i>Z</i> = 2. All Co(II) ions are in a tetrahedral environment with both ends of the ligand bound via O atoms to adjacent Co(II) ions, thus creating tetranuclear 16-membered rings. Compound Mn{[NH<sub>2</sub>(CH<sub>2</sub>PO<sub>3</sub>H)<sub>2</sub>]<sub>2</sub>(H<sub>2</sub>O)<sub>2</sub>} (<b>3</b>) crystallizes in the monoclinic space group <i>P</i>2<sub>1</sub>/n, with unit cell parameters <i>a</i> = 7.3668(11) Å, <i>b</i> = 8.1540(12) Å, <i>c</i> = 14.090(2) Å, <i>β</i> = 103.935(2)°, <i>V</i> = 821.4(2) Å<sup>3</sup>, and <i>Z</i> = 2. Four phosphate oxygen atoms and two water molecules are coordinated to the mononuclear octahedral Mn(II) ions. The amino groups are protonated and therefore do not coordinate to Mn(II). Compound <b>3</b> features a one-dimensional chain architecture stitched together by hydrogen bonds.