Effect of the apical ligand on the geometry and magnetic properties of copper(ii)/mesoxalate trinuclear units

• Published in: Dalton transactions : an international journal of inorganic chemistry 2017-04, Vol.46 (16), p.5260-5268
• Main Authors: Gil-Hernández, B, Calahorro, A J, Gili, P, Sanchiz, J
• Format: Article
• Language: English
• Subjects: Cationic; Cations; Ferromagnetism; LIGANDS; Long range order; MAGNETIC PROPERTIES; Networks; Order disorder; ORDER DISORDER RELATIONSHIPS; OXALATES; Polymerization; PROPERTIES
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c7dt00594f

Three new heterometallic metal-organic frameworks, namely, {(Ph P) [MnCu (Hmesox) Br(H O)]·H O} (1), {(Ph P) [CoCu (Hmesox) Br]} (2) and {(Ph P) [ZnCu (Hmesox) Br]·2.5H O} (3) were prepared and their structure and magnetic properties were investigated (H mesox = mesoxalic acid, Ph P = tetraphenylphosphonium). The structure of all the compounds consist of two interpenetrating opposite-chirality supramolecular cationic and polymeric anionic 3-D (10,3)-a networks, which results in chiral compounds. The anionic network is formed from the polymerization of [Cu (Hmesox) Br] units, working as three connectors, and M(ii) cations, working as three-connecting nodes, M = Mn(ii), Co(ii) and Zn(ii). The Ph P cations build the cationic chiral supramolecular network opposite to the anionic one. Compounds 1 and 2 exhibit long-range magnetic ordering with critical temperatures of 7.2 K and 6.9 K, respectively. However, compound 3 does not display long-range order, but shows ferromagnetic and antiferromagnetic coupling among the Cu(ii) ions. The magnetic interactions are studied by DFT calculations and compared with related Cu(ii)-mesoxalate compounds previously reported.