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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.

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. [ABSTRACT FROM AUTHOR]

A mixture of the E and Z isomers of ethyl 2-cyano-3-((4-fluorophenyl)amino) acrylate was synthesized and characterized by elemental analysis, attenuated total reflectance-Fourier transform infrared spectroscopy, 1 H and 13 C nuclear magnetic resonance spectroscopy. The structure of the Z isomer was determined by single crystal X-ray diffraction, which revealed a three-dimensional supramolecular network governed by C H⋯N, C H⋯O, and C H⋯F hydrogen bonds and π⋯π stacking interactions. The combination of these interactions plays an important role in stabilizing the self-assembly process and the molecular conformation. Hirshfeld surface analysis indicated the roles of the noncovalent interactions in the crystal packing, which were quantified by fingerprint plots and DFT calculations. [ABSTRACT FROM AUTHOR]