Tetranuclear copper(II) cubane complexes derived from self-assembled 1,3-dimethyl-5-(o-phenolate-azo)-6-aminouracil: structures, non-covalent interactions and magnetic property.
In: New Journal of Chemistry, Jg. 45 (2021-02-07), Heft 5, S. 2742-2753
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Zugriff:
Tetranuclear copper(II) complexes are of paramount importance in structural biology, and they are potential materials for magnetism and catalysis. To develop such a system, a new 6-aminoazouracil ligand, 1,3-dimethyl-5-(o-phenolate-azo)-6-aminouracil (H 2 L, 1) with a N u N a O (N u , uracil-N and N a , azo-N) chromophore was synthesized and used to generate a noble discrete doubly opened Cu 4 O 4 cubane-like cluster ([CuL] 4 ·2H 2 O, 2.2H 2 O) for studying magnetism. The coordination environment of Cu(II) is distorted square planar linked through phenolate-μ 2 -O bridges. The ligand crystallizes in the monoclinic space group P12 1 /c1 and the complex is in the tetragonal I4 1 /a space group with an S 4 symmetry. The ligand has two dissociable hydrogen atoms in the solution with pK 1 4.91 (hydrazone proton) and pK 2 9.68 (phenolic proton). In the solid state, the ligand exhibits displaced stacking (energy, −69.5 and −77.3 kJ mol −1 for the molecules A and B, respectively) and tetrel bonding interactions (energy, −43.8 kJ mol −1 ). In 2.2H 2 O, the symmetrical units are stacked to show weak noncovalent interactions. The magnetic property of 2.2H 2 O was investigated based on the cubane [Cu 4 O 4 ] core and discussed in detail, resulting in the exchange coupling parameter [(J 1 (short Cu⋯Cu distances) = −110.1(1) cm −1 , J 2 (long Cu⋯Cu distances) = −27.1(2) cm −1 )] that indicate a strong antiferromagnetic interaction between tetranuclear copper(II) ions through μ-phenolate linkers, which is a result of the interaction of d x 2 −y 2 orbitals in the square plane. The EPR study is concomitant with the results of magnetism. Thus, it could be a potential material in the field of antiferromagnetic spintronics as well. [ABSTRACT FROM AUTHOR]
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Titel: |
Tetranuclear copper(II) cubane complexes derived from self-assembled 1,3-dimethyl-5-(o-phenolate-azo)-6-aminouracil: structures, non-covalent interactions and magnetic property.
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Autor/in / Beteiligte Person: | Nandi, Nishithendu Bikash ; Purkayastha, Atanu ; Roy, Shaktibrata ; Kłak, Julia ; Ganguly, Rakesh ; Alkorta, Ibon ; Misra, Tarun Kumar |
Zeitschrift: | New Journal of Chemistry, Jg. 45 (2021-02-07), Heft 5, S. 2742-2753 |
Veröffentlichung: | 2021 |
Medientyp: | academicJournal |
ISSN: | 1144-0546 (print) |
DOI: | 10.1039/d0nj05232a |
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