Chelate ring size effects

Donor Group Orientation and Chelate Ring Size Effects... 

B.3. Chelate Ring Size Effects in Tridentate Ligand Systems... 

Effect of Chelate Ring Size on Complex Stability Comparison of Stabilities of Complexes of EDTA (Chelate Ring Size Five Involving the Two Nitrogens) and TMDTA (Analogous Chelate Ring Size Six ) ... 

The chelate ring size principle can have structural effects as well as effects on thermodynamic stability in aqueous solution. An example is coordination of metal ions by sugars (44). The cyclic polyol cts-inositol can coordinate metal ions in two distinct ways (Fig. 14) (45). In ax-ax-ax bonding (Fig. 14), the metal ion is part of three fused six-membered chelate rings. Alternatively, in ax-eq-ax coordination, the metal ion is part of two fused five-membered and one six-membered chelate rings. Angyal has noted that metal ions of radius more than 0.8 A adopt the ax-eq-ax structure (44), whereas with an ionic radius... 

Effect of Chelate Ring Size on Complex Stability with Metal Ions of Different Sizes Oxalate (Ring Size Five) and Malonate (Ring Size Six)°... 

The chromium-catalyzed coupling is extended to the intramolecular cycli-zation to the dials 43. The O-chelating silyl scavenger is used to control the stereoselectivity as shown in Scheme 25 [61,62]. The ring size effect on the stereoselectivity is also investigated. 

The effect of /rfive-coordinate aluminum alkyls have been discussed.94 Studies have also focused on the equilibrium between four-coordinate and five-coordinate isomers in compounds of the type [R2Al /i-0(GH2) ER1x ]2 (n = Z, 3 ER1x = OR1, SR1, NRX2) (shown in Figure 7(h) for n = Z). Factors that control this equilibrium and hence the coordination around the aluminum include the steric bulk of the substitutent at the aluminum (R), and the Lewis base donor R1, the basicity of the neutral donor group ER1, and the chelate ring size (as determined by n).95... 

Table 4.16 Consultants for Extraction of Actinide Amides from Nitrate Solutions into an Organic Solvent Showing the Effect of Chelate Ring Size...

The redox properties of the copper(II) ion in saturated polyaza macrocyclic complexes CuN4 and CuNj have been shown1020 to vary with the chelate ring size, and the very negative E° values (Figure 62) are consistent with a macrocyclic effect , from stability constant measurements.976... 

Tesic, Z.L., Janfic, T.J., Malimar, M.J. and Celap, M.B. (1989) Effect of chelate ring size of diamine cobalt(II) complexes on RF values obtained by paper chromatography. J. Chromatogr., 481, 471-476. 

The resolution of uns-cis (or P-cis)-[CoL(edda)] (L = C03, ox, mal) and their c.d. spectra have been compared with those of the S-cis (or ot-cis) isomers, in an attempt to assess the contribution of vicinal and configurational effects and chelate ring size to rotatory strengths.389 The changes observed in the c.d. spectra could be related to the arrangement of the chelate rings and to the configuration about the asymmetric... 

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