Fluorenyl-Schiff-base ligands and their dicopper(II) complexes. Synthesis, structural and spectroscopic characterization and DNA binding assays
| Autor: | Priscilla J. Zambiazi, Guilherme Sippel Machado, Manfredo Hörner, Fábio Souza Nunes, Bernardo A. Iglesias, Ronny R. Ribeiro, Fabiane dos Santos Carlos, Marcelo Carpes Nunes, Guilherme A. de Moraes |
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| Rok vydání: | 2018 |
| Předmět: |
Schiff base
010405 organic chemistry Chemistry Ligand Carbon-13 NMR Fluorene 010402 general chemistry 01 natural sciences 0104 chemical sciences law.invention Inorganic Chemistry Crystallography chemistry.chemical_compound Salicylaldehyde law Materials Chemistry Molecule Orthorhombic crystal system Physical and Theoretical Chemistry Electron paramagnetic resonance |
| Zdroj: | Polyhedron. 144:18-29 |
| ISSN: | 0277-5387 |
| DOI: | 10.1016/j.poly.2018.01.003 |
| Popis: | Schiff-base ligands L1 and L2 containing fluorene as fluorophore were synthesized thorough condensation of salicylaldehyde and 2,6-diformyl 4-methylphenol with 6-(9-fluorenyl)-1,4,8,11-tetraazaundecane-5,7-dione, respectively. A comprehensive spectroscopic analysis was performed by elemental analysis, ESI-MS, 1H and 13C NMR, FTIR, EPR, UV–Vis and emission spectroscopies. Ligand L1 binds copper(II) to form [Cu2(L1)2]·2H2O that crystallizes in orthorhombic system and space group P21/n. Assignments to the UV–Vis and EPR spectra allowed access to Jahn–Teller stabilization energies (EJT) at 6345 and 5435 cm−1 for complexes [Cu2(L1)2]·2H2O and [Cu2(L2)](ClO4)4·4H2O, respectively, and to their corresponding spin orbit coupling constants λ = −428 and −398 cm−1. The EPR spectrum of [Cu2(L2)](ClO4)4·4H2O in the solid state showed a half-field ΔmS = ±2 transition, supporting the dicopper composition. The fluorenyl copper(II) derivatives demonstrated a moderate binding to ct-DNA than the fluorenyl-ligand molecule following the increasing order of (Kb): L1 |
| Databáze: | OpenAIRE |
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