Copper ligand exchange

TABLE 5 Copper Ligand Exchange-Based Chiral Columns Commonly Used in Pharmaceutical ... 

Some ligand-exchange CSPs have been used at preparative level [31, 32]. In this case it must be taken into account that an extraction process, to remove the copper salts added to the mobile phase, must be performed following the chromatographic process [33]. Teicoplanin, in contrast, resolves all ordinary a and (3-amino acids with mobile phases consisting of alcohol/water mixtures. No buffer is needed in the... 

The most widely used approach for the separation of enantiomers by TLC is based on a ligand exchange mechanism using commercially available reversed-phase plates impregnated with a solution of copper acetate and (2S,4R,2 RS)-4-hydroxy-l-(2-hydroxydodecyl)proline in optimized amounts. Figure 7.9 (10,97,98,107-109). Enantiomers are separated based on the differences in the stability of the diastereomeric complexes formed between the sample, copper, and the proline selector. As a consequence, a prime requirement for separation is that the seumple must be able to form complexes with copper. Such compounds include... 

The transfer of a quadridentate N2S2-donor ligand from M2+ (M = Cr, Mn, Fe, Co or Ni) to Cu2+ (271), already mentioned in Section V.A.l, has a formal connection with an investigation of the mechanism of copper delivery to metalloproteins, such as copper zinc superoxide dismutase. Both are ligand exchange reactions of the type ML + CuL ML + CuL (300). 

Chiralccl WM Ligand exchange Amina acid-copper... 

Chiral HyproCu = SilOOPolyol Ligand exchange Hydroxyproline-copper... 

In order to increase the rate of the motions, a new rotaxane in which the metal center is as accessible as possible was prepared, the ligand set around the copper center being thus sterically little hindering compared to previous related systems. Ligand exchange within the coordination sphere of the metal is thus... 

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