Ligand-Directed Assembly of Azide-Bridged Tetranuclear, One-Dimensional and Two-Dimensional Cu(II) Complexes: Synthesis, Crystal Structure and Magnetic Properties

• Published in: Crystal growth & design Vol. 12; no. 7; pp. 3436 - 3443
• Main Authors: Shi, Wen-Bo, Cui, Ai-Li, Kou, Hui-Zhong
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 03.07.2012
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Magnetic properties and materials; Materials science; Organic compounds; Other ferromagnetic metals and alloys; Other materials; Physics; Specific materials; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Studies of specific magnetic materials; Sodium; Copper sulfide; Ferromagnetic materials; Ligands; Magnetic structure; Tetranuclear complex; Copper; Van der Waals radius; Copper complexes; Magnetic properties; Crystal structure
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg201605w

Three Cu(II) complexes of tetranuclear [Cu4(cmpy)4(N3)5Cl3] (1), 1D chain [Cu2(cea)2(N3)4] n (2), and two-dimensional layer [Cu5(cmpy)2(N3)10] n (3) were synthesized by controlling the molar ratio of Cu(ClO4)2·6H2O, pyCH2Cl·HCl (cmpy·HCl), or H2NCH2CH2Cl·HCl (cea·HCl) and sodium azide. For complexes 1–3, the atom Cl of the ligands (cmpy and cea) is located at the Jahn–Teller axis of Cu(II) with the weak Cu–Cl separations of 2.920(1) - 3.177(1) Å that are shorter than the sum of van der Waals radii of Cu and Cl atoms, 3.3 Å. The azide ligands coordinate to Cu(II) in the equatorial or basal plane of the coordination pyramid, favoring strong magnetic coupling. The bridging angles of Cu–Nazido–Cu in complexes 1–3 are nearly 101°, corresponding to the presence of global ferromagnetic coupling. The end-to-end azide bridges appear exclusively in complex 3, linking the end-on azide-bridged 1D chains into a 2D layer.