Self-Assembly of the Hexabromorhenate(IV) Anion with Protonated Benzotriazoles: X‑ray Structure and Magnetic Properties

• Published in: Crystal growth & design 2014-11, Vol.14 (11), p.5985-5990
• Main Authors: Martínez-Lillo, José, Kong, John, Julve, Miguel, Brechin, Euan K
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of nanofabrication; Organic compounds; Physics; Self-assembly; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg5011693

Two novel ReIV compounds of formulas [HBTA]2­[ReIVBr6] (1) and [HMEBTA]2­[ReIVBr6] (2) [BTA = 1H-benzotriazole and MEBTA = 1-(methoxy­methyl)-1H-benzotriazole] have been synthesized and magneto-structurally characterized. 1 and 2 crystallize in the triclinic system with space group P1̅. In both compounds, the rhenium ion is six-coordinate, bonded to six bromo ligands in a regular octahedral geometry. Short ReIV–Br···Br–ReIV contacts, π–π stacking, and H-bonding interactions occur in the crystal lattice of both 1 and 2, generating novel supramolecular structures based on the ReIV. The different dispositions of the cations and the intermolecular Br···Br contacts in 1 and 2 play an important structure–property role, with the magnetic properties of 1 and 2 revealing a significant antiferromagnetic coupling between ReIV ions through intermolecular Br···Br interactions. In 1, these interactions account for a maximum in the magnetic susceptibility at ca. 10 K.