Synthesis and sulfur oxygenation of a (N3S)Ni complex related to nickel-containing superoxide dismutase.
A nickel(II) thiolate complex incorporating three N-donor types (amino, amido, and imidazole) has been synthesized and characterized. The (N(3)S)Ni complex, [N-{2-[(2-mercapto-2-methylpropyl)amino]ethyl}-1-methylimidazole-2-carboxamido]nickel(II) (1), is stable in the presence of O(2) but readily forms the sulfinato (RSO(2)(-)) derivative 2 upon the addition of H(2)O(2). Electrochemical investigations of 1 reveal an irreversible sulfur-based oxidation at +0.17 V vs Fc(+)/Fc (200 mV/s) that shifts to +0.81 V upon oxidation to 2. Density functional theory investigations of 1 reveal a highest occupied molecular orbital that is predominantly sulfur-based, consistent with the observed sulfur-based oxidation and O(2) stability.
Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.
Christopher S
CS
Mullins
Craig A
CA
Grapperhaus
Brian C
BC
Frye
Larry H
LH
Wood
Amy J
AJ
Hay
Robert M
RM
Buchanan
Mark S
MS
Mashuta
D000577:Amides / Q000737:chemistry; D000588:Amines / Q000737:chemistry; D001665:Binding Sites; D007093:Imidazoles / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010084:Oxidation-Reduction; D011789:Quantum Theory; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry*; D013482:Superoxide Dismutase / Q000737:chemistry*
D000577:Amides; D000588:Amines; D007093:Imidazoles; C546380:N-(2-((2-mercapto-2-methylpropyl)amino)ethyl)-1-methylimidazole-2-carboxamido nickel(II); D009942:Organometallic Compounds; D013438:Sulfhydryl Compounds; D013455:Sulfur; D009532:Nickel; D013482:Superoxide Dismutase