Publication Type Journal Article
Title Nickel(II), Copper(II) and Palladium(II) Complexes with Bis-Semicarbazide Hexaazamacrocycles: Redox-Noninnocent Behavior and Catalytic Activity in Oxidation and C-C Coupling Reactions
Authors Anatolie Dobrov Anastasia Fesenko Alexander Yankov Iryna Stepanenko Denisa Darvasiova Martin Breza Peter Rapta L.M.D.R.S. Martins Armando J.L. Pombeiro Anatoly Shutalev Vladimir B. Arion
Groups CCC
Journal INORGANIC CHEMISTRY
Year 2020
Month August
Volume 59
Number 15
Pages 10650-10664
Abstract Nickel(II), copper(II), and palladium(II) complexes MLH, where M = Ni (1), Cu (2), Pd (3), and MLOMe, where M = Ni (4), Cu (5), Pd (6), have been prepared by reactions of NiCl2 center dot 6H(2)O, Cu(OAc)(2)center dot H2O, and PdCl2(MeCN)(2) with 14-membered bis-semicarbazide hexaazamacrocycles H2LH and H2LOMe in dimethylformamide (DMF). The compounds were characterized by elemental analysis, ESI mass spectrometry, IR, UV-vis, and 1D (H-1, C-13) and 2D (H-1-H-1 COSY, H-1-H-1 TOCSY, H-1-H-1 NOESY, H-1-C-13 HSQC, H-1-C-13 HMBC) NMR spectra (1, 3, 4, and 6), and X-ray diffraction (2, 4-6). The complexes with (MN4)-N-II coordination environment have S = 0, 1/2, 0 ground states for Ni, Cu, and Pd, respectively. The electrochemical behavior of 1-6 was investigated in detail. The electronic structures of 1e-oxidized species were studied by EPR, UV-vis-NIR spectroelectrochemistry, and DFT calculations, indicating the redox-noninnocent behavior of the ligands. Compounds 1-6 were tested in the oxidation of styrene and C-C coupling (Henry and Knoevenagel condensations). Compounds 2 and 5 selectively catalyze the microwave-assisted oxidation of neat styrene to benzaldehyde (up to 88\% yield), whereas the 1 and 4 catalytic systems afforded up to 99\% beta-nitroethanol yield with an appreciable diastereoselectivity toward the formation of the anti isomer.
DOI http://dx.doi.org/10.1021/acs.inorgchem.0c01119
ISBN
Publisher AMER CHEMICAL SOC
Book Title
ISSN 0020-1669
EISSN 1520-510X
Conference Name
Bibtex ID ISI:000558727500031
Observations
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