Nicotinamide complex of silver(III) with expanded coordination number

Authors

Yunfu Sun, University of Rhode Island
Louis J. Kirschenbaum, University of Rhode IslandFollow

Document Type

Article

Date of Original Version

2018

Department

Chemistry

Abstract

In strongly alkaline media ([OH^-] ≥ 0.12 M), nicotinamide (nica) forms a complex with square-planar Ag(OH)₄^- [nica] ≥ 0.05 M. The complex decomposes in seconds to nicotinamide N-oxide. The correlation of maximum absorbance of the complex with concentrations of nicotinamide and hydroxide requires that the complex is either the five-coordinate Ag(OH)₄(H_-1nica)^2- or the six-coordinate Ag(OH)₅(nica)^2-. Comparison with the reactions of Ag(OH)₄^- with nicotinate ion (nic^-) and acetamide under similar conditions indicates that nicotinamide coordinates with Ag(OH)₄^- by the amido group rather than the nitrogen on the pyridine ring or the amido oxygen. Kinetics of the Ag(III)- nica redox reaction are consistent with direct reaction between nicotinamide and uncoordinated Ag(OH₄)^-. Oxidation takes place at the pyridine ring, yielding nicotinamide N-oxide. Silver(III) is reduced to monovalent silver.

Citation/Publisher Attribution

Yunfu Sun & Louis J. Kirschenbaum (2018) Nicotinamide complex of silver(III) with expanded coordination number, Journal of Coordination Chemistry, DOI: 10.1080/00958972.2018.1497790.

Available at: https://doi.org/10.1080/00958972.2018.1497790