The Cu(ii) heptanuclear complex (Cu7atac) was synthesised using the hydrated amino acid ligand 2-(5-amino-1H-1,2,4-triazol-3-yl)acetic acid (Hatac·H2O). Single crystal X-ray diffraction analysis revealed a μ3-hydroxo bridged Cu(ii) heptanuclear complex, consisting of two triangular subunits and one Cu(ii) ion as a bridge with the formula [Cu7(atac)6(μ3-OH)2(NO3)2(H2O)10](NO3)4. The magnetic behaviour of this discrete 0D complex shows strong antiferromagnetic couplings between Cu(ii) mediated by N,N bonding and an anti-anti modes of the carboxylate anion of the ligand atac-. The magnetic data were fitted considering a 3J model. To support the model used to fit the magnetic data of the Cu7atac complex, theoretical calculation methods (complete active space self-consistent field, CASSCF, density functional theory (DFT) using the UKS TPSS/Def2-TZVP//Def2-SVP level and periodic boundary conditions (PBC) using PBE/DZVP-MOLOPT-GTH) were performed to obtain the spin states, spin density map and J couplings. The theoretical results suggest that Cu7atac is a spin-frustrated complex in the ground state, in which the doublet spin state co-exists with the quartet spin state.
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http://dx.doi.org/10.1039/c9dt04501e | DOI Listing |
RSC Adv
September 2024
Department of Chemistry, Graduate School of Science, Osaka Metropolitan University Osaka 558-8585 Japan
Mixed-ligand and mixed-metal trinuclear complexes bearing two {Pt-bisNHC-C1} moieties, [{Pt(bisNHC-C1)}(ML)(μ-S)] (ML = Pt(bisNHC-C2), = 2; ML = Pt(bisNHC-C3), = 2; ML = Rh(cod), = 1; ML = RhCp*, = 2), where bisNHC-C1, bisNHC-C2 and bisNHC-C3 represent methylene-, ethylene- and propylene-bridged bis-NHC ligands, respectively, were synthesised and structurally characterised. Reactions of these complexes with a half eq. of Ag(i) ions were examined using H and Pt NMR spectroscopy.
View Article and Find Full Text PDFInorg Chem
April 2024
Departamento de Química Inorgánica, Universidad de Valencia, Burjasot, Valencia 46100, Spain.
We present a bifunctional heptanuclear cobalt(II)/cobalt(III) molecular complex formulated as [Co(μ-OH)(HL)(HL)](NO)·6HO () (where HL is 2,2'-(((1E,1'E)-((2-hydroxy-5-methyl-1,3-phenylene)bis(methanylylidene))bis(azanylylidene))bis(propane-1,3-diol)) and HL is 2-amino-1,3-propanediol). Compound has been characterized by single-crystal X-ray diffraction analysis along with other spectral and magnetic measurements. Structural analysis indicates that contains a mixed-valence Co cluster where a central Co(II) ion is connected to six different Co centers (four Co and two Co ions) by four μ-OH groups, giving rise to a planar heptanuclear cluster that resembles a molecular fragment of a layered double hydroxide (LDH).
View Article and Find Full Text PDFDalton Trans
March 2024
Faculty of Health Science, University of Ss. Cyril and Methodius, 917 01 Trnava, Slovakia.
The structure and magnetic properties of a complex containing a {DyCu} core are presented. In 1, the Dy(III) are 9- and the Cu(II) are 4-, 5- and 6-coordinated. Antiferromagnetic interactions cause an irregular energy spectrum with the ground state = 25/2.
View Article and Find Full Text PDFMolecules
January 2024
Engineering Research Center of Advanced Rare Earth Materials (Ministry of Education), Department of Chemistry, Tsinghua University, Beijing 100084, China.
Heptanuclear {Gd} (complex ) and tetradecanuclear {Gd} (complex ) were synthesized using the rhodamine 6G ligand HL (rhodamine 6G salicylaldehyde hydrazone) and characterized. Complex has a rare disc-shaped structure, where the central Gd ion is connected to the six peripheral Gd ions via CHO/μ-OH bridges. Complex has an unexpected three-layer double sandwich structure with a rare μ-O ion in the center of the cluster.
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August 2023
Department of Chemistry, University of Kansas, Lawrence, KS 66045, USA.
Oligo- and polyazulenes are attractive π-conjugated building blocks in designing advanced functional materials. Herein, we demonstrate that anchoring one or both isocyanide termini of the redox non-innocent 2,2'-diisocyano-6,6'-biazulenic π-linker (1) to the redox-active [Cr(CO)] moiety provided a convenient intramolecular redox reference for unambiguously establishing that the 6,6'-biazulenic scaffold undergoes a reversible one-step 2 reduction governed by reduction potential compression/inversion. Treatment of bis(η-naphthalene)chromium(0) with six equiv.
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