Blake R. Reed, Maryam A. Yousif, Richard L. Lord
Feb 1, 2017
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0
Influential Citations
9
Citations
Journal
Organometallics
Abstract
A series of nickel complexes with potentially redox active bis(aldimino)pyridine ligands [NNN] ([NNN] = 1,1′-(pyridine-2,6-diyl)bis(N-arylmethanimine), where aryl = 2,6-diisopropylphenyl, mesityl, 4-methoxyphenyl, 4-trifluoromethylphenyl, and 3,5-bis(trifluoromethyl)phenyl) were synthesized, and their properties and reactivities were investigated as a function of the overall oxidation state of the system. (Ni[NNN])2+ complexes of ligands featuring bulky electron-rich substituents (1a-Br2 and 1b-Br2, [NNN] = 1,1′-(pyridine-2,6-diyl)bis(N-(2,6-diisopropylphenyl)methanimine) and 1,1′-(pyridine-2,6-diyl)bis(N-mesitylmethanimine), respectively) demonstrated five electrochemical reduction events, the first three of which were quasi-reversible. In contrast, only two quasi-reversible reductions were observed for the less bulky and electron-deficient N-aryl substituents 4-(trifluoromethyl)phenyl and 3,5-bis(trifluoromethyl)phenyl. Chemical reduction of 1a-Br2 and 1b-Br2 with 1 equiv of KC8 or CoCp*2 forms (Ni[NNN]...