Reaction of a model siderophore with Ni(II), Co(II) and Zn(II) in aqueous solution: kinetics and spectroscopy.
A spectroscopic study was performed showing that the [Fe(III)(L(2-))(2)](1-) (L(2-)=dopacatecholate) complex reacts with Ni(II), Co(II) and Zn(II) in an aqueous solution containing S(2)O(3)(2-) resulting in the soluble [M(L(1-))(3)](1-) (L(1-)=dopasemiquinone; M=Ni(II), Co(II) or Zn(II) complex species. The Raman and IR spectra of the [CTA][M(L(1-))(3)] complexes, CTA=hexadecyltrimethylammonium cation, in the solid state were obtained. The kinetic constants for the metal substitution reactions were determined at four different temperatures, providing values for DeltaH(not equal), DeltaS(not equal) and DeltaG(not equal). The reactions were slow (k=10(-11) Ms(-1)) and endothermic. The system investigated can be considered as a simplified model to explain some aspects of siderophore chemistry.
Laboratory of Environmental Physical Chemistry, Department of Chemistry, CCE, Londrina State University, Londrina, Pr 86051-990, Brazil. barreto@uel.br
Wagner J
WJ
Barreto
Romulo A
RA
Ando
Paulo S
PS
Santos
Waleria P
WP
Silva
D003035:Cobalt / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D007700:Kinetics; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D017262:Siderophores / Q000138:chemical synthesis / Q000737:chemistry*; D013057:Spectrum Analysis; D015032:Zinc / Q000737:chemistry*
D009942:Organometallic Compounds; D017262:Siderophores; D003035:Cobalt; D009532:Nickel; D007501:Iron; D015032:Zinc