New Sensitive and Selective Chemical Sensors for Ni 2+ and Cu 2+ Ions: Insights into the Sensing Mechanism through DFT Methods.

Autor: Treto-Suárez MA; Doctorado en Fisicoquímica Molecular, Universidad Andres Bello, Ave. República #275, 8320000, Santiago de Chile, Chile., Tapia J; Universidad Bernardo OHiggins, Facultad de Salud, Departamento de Ciencias Quı́micas y Biológicas, General Gana 1702, Santiago, Chile.; Millennium Nuclei on Catalytic Processes towards Sustainable Chemistry (CSC), Santiago, Chile., Hidalgo-Rosa Y; Doctorado en Fisicoquímica Molecular, Universidad Andres Bello, Ave. República #275, 8320000, Santiago de Chile, Chile.; Millennium Nuclei on Catalytic Processes towards Sustainable Chemistry (CSC), Santiago, Chile., Páez-Hernández D; Doctorado en Fisicoquímica Molecular, Universidad Andres Bello, Ave. República #275, 8320000, Santiago de Chile, Chile.; Center of Applied Nanosciences (CANS), Chile República #275, 8320000, Santiago de Chile, Chile., Molins E; Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Spain., Zarate X; Instituto de Ciencias Químicas Aplicadas, Theoretical and Computational Chemistry Center, Facultad de Ingeniería, Universidad Autónoma de Chile, Av. Pedro de Valdivia 425, 7500912, Santiago, Chile., Schott E; Departamento de Química Inorgánica, Facultad de Quı́mica y Farmacia, Centro de Energı́a UC, Centro de Investigación en Nanotecnologı́a y Materiales Avanzados CIEN-UC, Pontificia Universidad Católica de Chile, Avenida Vicuña Mackenna, 4860, 7820244, Santiago, Chile.; Millennium Nuclei on Catalytic Processes towards Sustainable Chemistry (CSC), Santiago, Chile.
Jazyk: angličtina
Zdroj: The journal of physical chemistry. A [J Phys Chem A] 2020 Aug 13; Vol. 124 (32), pp. 6493-6503. Date of Electronic Publication: 2020 Jul 31.
DOI: 10.1021/acs.jpca.0c03834
Abstrakt: We report the synthesis and theoretical study of two new colorimetric chemosensors with special selectivity and sensitivity to Ni 2+ and Cu 2+ ions over other metal cations in the CH 3 CN/H 2 O solution. Compounds ( E )-4-((2-nitrophenyl)diazenyl)- N , N -bis(pyridin-2-ylmethyl)aniline (A) and ( E )-4-((3-nitrophenyl)diazenyl)- N , N -bis(pyridin-2-ylmethyl)aniline (B) exhibited a drastic color change from yellow to colorless, which allows the detection of the mentioned metal cations through different techniques. The interaction of sensors with these metal ions induced a new absorption band with a hypsochromic shift to the characteristic signal of the free sensors. A theoretical study via time-dependent density functional theory (TD-DFT) was performed. This method has enabled us to reproduce the hypsochromic shift in the maximum UV-vis absorption band and explain the selective sensing of the ions. For all of the systems studied, the absorption band is characterized by a π → π* transition centered in the ligand. Instead of Ni 2+ and Cu 2+ ions, the transition is set toward the σ* molecular orbital with a strong contribution of the 3d x 2 - y 2 transition (π → 3d x 2 - y 2 ). These absorptions imply a ligand-to-metal charge transfer (LMCT) mechanism that results in the hypsochromic shift in the absorption band of these systems.
Databáze: MEDLINE
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