Ferrer S, Hernández-Gil J, Valverde-Muñoz FJ, Lloret F, Castiñeiras A. Hexanuclear Cu
3O-3Cu triazole-based units as novel core motifs for high nuclearity copper(ii) frameworks.
RSC Adv 2019;
9:29357-29367. [PMID:
35528438 PMCID:
PMC9071962 DOI:
10.1039/c9ra05922a]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/06/2019] [Indexed: 12/25/2022] Open
Abstract
The asymmetric 3,5-disubstituted 1,2,4-triazole ligand H2V (5-amino-3-picolinamido-1,2,4-triazole) by reaction with an excess of Cu(ii) perchlorate (Cu : H2V being 12 : 1) has produced a novel hexanuclear {Cu6(μ3-O/H)(HV/V)3} fragment, with one triangular Cu3(μ3-O/H) group connected to three peripheral single Cu(ii) ions through a cis-cis-trans bridging mode of the ligand, which is the building block of the three structures described here: one hexanuclear, [Cu6(μ3-O)(HV)3(ClO4)7(H2O)9]·8H2O (1), one dodecanuclear, [Cu12(μ3-O)2(V)6(ClO4)5(H2O)18](ClO4)3·6H2O (2), and one tetradecanuclear 1D-polymer, {[Cu14(μ3-OH)2(V)6(HV)(ClO4)11(H2O)20](ClO4)2·14H2O} n (3), the last two containing hexanuclear subunits linked by perchlorato bridges. The Cu-Cu av. intra-triangle distance is 3.352(2) Å and the Cu(central)-Cu(bridged external) av. distance is 5.338(3) Å. The magnetic properties of the hexanuclear "Cu3O-3Cu" cluster have been studied, resulting as best fit parameters: g = 2.18(1), J(intra-triangle) = -247.0(1) cm-1 and j(central CuII - external CuII) = -5.15(2) cm-1.
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