TY - JOUR
T1 - Synthesis, structures, electrochemical and quantum chemical investigations of Ni(ii) and Cu(ii) complexes with a tetradentate Schiff base derived from 1-(2-thienyl)-1,3-butanedione
AU - Ahumada, Guillermo
AU - Oyarce, Jocelyn
AU - Roisnel, Thierry
AU - Kahlal, Samia
AU - Del Valle, María Angélica
AU - Carrillo, David
AU - Saillard, Jean Yves
AU - Hamon, Jean René
AU - Manzur, Carolina
N1 - Funding Information:
We thank F. Lambert (CRMPO, Rennes) for helpful assistance with the MS measurements. Financial support from the Fondo Nacional de Desarrollo Científico y Tecnológico [FONDECYT (Chile), grant no. 1140903 (C. M. and D. C.)], FONDEQUIP [EQM130154], the Vicerrectoría de Investigación y Estudios Avanzados, Pontificia Universidad Católica de Valparaíso, Chile (C.M. and D.C.), the CNRS and the Universitéde Rennes 1 is gratefully acknowledged. The GENCI-CINES and GENCI-IDRISS French national computer centers are acknowledged for computational resources (Grant a0010807367). This research has been performed as part of the Chilean-French International Associated Laboratory ‘‘Multifunctional Molecules and Materials’’ (LIA M3 - CNRS No. 1207). G. A. and J. O. thank the CONICYT (Chile) for support with graduate fellowships No. 21120098 and No. 21171363, respectively.
Publisher Copyright:
© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
PY - 2018
Y1 - 2018
N2 - Double condensation of the newly prepared 1-(2-thienyl)-1,3-butanedione with ethylenediamine led to the formation of a novel symmetrical Schiff base proligand bearing two potentially electropolymerizable 2-thienyl groups. Both organic species were obtained in 55 and 80% yields, respectively. They exist in their respective keto-enol and enaminone tautomeric forms that were computed to be more stable by 8.6 and 30.3 kcal mol−1 than their β-diketone and keto-imine isomers. The corresponding Ni(ii) and Cu(ii) complexes featuring a N2O2-tetradentate Schiff base ligand were readily synthesized upon reaction of the diprotic Schiff base precursor with the appropriate hydrated metal acetates, and isolated as neutral, air and thermally stable solids in excellent yields (84 and 90%). The four compounds were characterized using various analytical and spectroscopic methods, and by an X-ray diffraction study for the two coordination complexes. Both Ni(ii) and Cu(ii) metal ions are four-coordinated and adopt a perfect square planar environment (τ4 values of 0.036 and 0.025) with two nitrogen and two oxygen atoms as donors. Both complexes were analyzed by cyclic voltammetry experiments showing a decrease of the current response per cycle, indicating the formation of oligomeric units. This was verified using their doping/undoping responses. The optimized geometries of the four compounds as well as the electronic structures of the two Ni(ii) and Cu(ii) complexes and their respective cations were analysed through DFT calculations, allowing the provision of a consistent view of their structure and properties. TDDFT calculations were used to interpret the major features of the UV-vis spectra.
AB - Double condensation of the newly prepared 1-(2-thienyl)-1,3-butanedione with ethylenediamine led to the formation of a novel symmetrical Schiff base proligand bearing two potentially electropolymerizable 2-thienyl groups. Both organic species were obtained in 55 and 80% yields, respectively. They exist in their respective keto-enol and enaminone tautomeric forms that were computed to be more stable by 8.6 and 30.3 kcal mol−1 than their β-diketone and keto-imine isomers. The corresponding Ni(ii) and Cu(ii) complexes featuring a N2O2-tetradentate Schiff base ligand were readily synthesized upon reaction of the diprotic Schiff base precursor with the appropriate hydrated metal acetates, and isolated as neutral, air and thermally stable solids in excellent yields (84 and 90%). The four compounds were characterized using various analytical and spectroscopic methods, and by an X-ray diffraction study for the two coordination complexes. Both Ni(ii) and Cu(ii) metal ions are four-coordinated and adopt a perfect square planar environment (τ4 values of 0.036 and 0.025) with two nitrogen and two oxygen atoms as donors. Both complexes were analyzed by cyclic voltammetry experiments showing a decrease of the current response per cycle, indicating the formation of oligomeric units. This was verified using their doping/undoping responses. The optimized geometries of the four compounds as well as the electronic structures of the two Ni(ii) and Cu(ii) complexes and their respective cations were analysed through DFT calculations, allowing the provision of a consistent view of their structure and properties. TDDFT calculations were used to interpret the major features of the UV-vis spectra.
UR - http://www.scopus.com/inward/record.url?scp=85056883588&partnerID=8YFLogxK
U2 - 10.1039/c8nj04923h
DO - 10.1039/c8nj04923h
M3 - Article
AN - SCOPUS:85056883588
VL - 42
SP - 19294
EP - 19304
JO - New Journal of Chemistry
JF - New Journal of Chemistry
SN - 1144-0546
IS - 23
ER -