Citrate-ligand exchange

Recent data show that Fe-WEHS could be used by dicots via a reduction-based mechanism more efficiently than other Fe-chelates that may be present in the rhizosphere, such as Fe-phytosiderophores and Fe-citrate (Cesco et al., 2006). It has been shown that Fe-WEHS could also be used by barley plants (strategy II) via a mechanism possibly involving ligand exchange between phytosiderophores and WEHS (Cesco et al., 2002). 

The complex formation between Ni(ii) and acetate ions in aqueous solution has been studied by C NMR. Equilibrium quotients (132) and rate parameters (133) for the ligand exchange processes are reported. Complexes of hydroxy-acids (134) and iminodiacetates RN(CH2C0 )2 (135) have been the subjects of further studies. Co(ii) complexes of malate, citrate, isocitrate, and monomethylcitrate all exhibit large shifts which may be accounted for by assuming a common structural unit [22] in which the ligand is tridentate. Nickel(ii)... 

These compounds are easily obtained in high yields at no carrier-added level, and they are suitable precursors in the synthesis of new Tc complexes by ligand exchange (or transchelation) (Spies et al. 1980). Other polyhydroxy or hydroxyl acids have been under investigation, such as glycolate, glucarate, tartrate, or citrate, which have been used in transchelation procedures. 

A catalyst might be a ligand, which rapidly forms an intermediary coordination complex such as gluconate, DTPA, and citrate (Davison 1983). Ligand exchange is applied when complex formation with a certain ligand is slow relative to formation of reduced, hydrolized technetium, resulting in a poor radiochemical yield. 

Glycoconjugates Used in Thiolated Ligand Exchange on Citrate-Capped (or Analognes) Gold Nanoparticles... 

AuNPs capped citrate molecules Ligand exchange process... 

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