Steric effect on construction of extended architectures of Ni(II) complexes directed by intermolecular C-H?KF and C-H?KO interactions
H. Kwak1, G.H. Eom2, S.H. Lee3, H.G. Koo4, S.P. Jang5, J. Lee6, W. Shin7, M.S. Lah8, C. Kim9, S.-J. Kim10, Y. Kim11
1 Department of Fine Chemistry, and Eco-Product and Materials Education Center, Seoul National University of Technology, Seoul 139-743, Korea 2 Department of Fine Chemistry, and Eco-Product and Materials Education Center, Seoul National University of Technology, Seoul 139-743, Korea 3 Department of Fine Chemistry, and Eco-Product and Materials Education Center, Seoul National University of Technology, Seoul 139-743, Korea 4 Department of Fine Chemistry, and Eco-Product and Materials Education Center, Seoul National University of Technology, Seoul 139-743, Korea 5 Department of Fine Chemistry, and Eco-Product and Materials Education Center, Seoul National University of Technology, Seoul 139-743, Korea 6 Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea 7 Department of Chemistry and Interdisciplinary Program of Integrated Biotechnology, Sogang University, Seoul 121-742, Korea 8 Department of Applied Chemistry, College of Science, Hanyang University, Ansan-si, Gyeonggi-do 426-791, Korea 9 Department of Fine Chemistry, and Eco-Product and Materials Education Center, Seoul National University of Technology, Seoul 139-743, Korea, chealkim@snut.ac.kr 10 Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea, sjkim@ewha.ac.kr 11 Department of Chemistry and Nano Science, Ewha Womans University, Seoul 120-750, Korea
Ключевые слова: Pyridine carboxamide, nickel(II) complex, crystal structure, electronic effect, weak interactions, hydrogen bond, supramolecular architecture, cyclic voltammetry
Страницы: 957-964
Аннотация
Five new Ni(II) complexes with pyridine carboxamide ligands have been synthesized and the crystal structures of three of the complexes were determined. Strong distortion effects of 6-methyl substitution were observed in the complexes with 6-methyl-substituted pyridyl bpb ligands. The C-H?KF and C-H?KO hydrogen bond interactions build extended architectures in the crystals studied. This result suggests that the steric effect of 6-methyl substitution plays an important role in the distortion of the structure, and the 6-methyl substitution can facilitate hydrogen bond interactions between methyl hydrogen atoms and O(carbonyl) or F atoms. Twelve Ni(II) complexes, including seven complexes reported previously, show reversible redox behavior, implying that the reduced Ni(I) state of each complex is stable in the time scale of CV measurement. The steric effect of R1 substituent and the electronic effects of X1 and X2 groups were found to be the main factors contributing to the shift of the redox potential of the Ni(II) complexes.
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