Ligand macrocyclic

Sulfur-containing ligands. Macrocyclic effects have also been documented in mixed donor systems. The Cu(ii) complex of the 14-mem-bered (cis) N2S2-donor analogue of cyclam exhibits a substantial macrocyclic effect with a log K difference of 4.6 relative to the corresponding open-chain species (Figure 6.2) (Micheloni, Paoletti, Siegfried-Hertli Kaden, 1985). The effect in this case is mainly due to a favourable... 

The first section will consist of the synthesis and reactions of imine chelates, as this is the most widely and consistently used aspect of ligand reactions. The discussion will be subdivided according to the types of ligands involved and will range from bidentate through to multidentate ligands, macrocycles and cage compounds. 

The use of pyrrole as the source of a donor atom in Schiff base ligand macrocycles is relatively rare. This probably just reflects the long and tedious synthesis of the required starting 2,5-diformylpyrrole (92), rather than any kind of general philosophic opposition to using this heterocycle. Consistent with this supposition is the realization that the publication [54] of a relatively facile route to 2,5-diformylpyrrole (92) in 1981 was reflected soon thereafter in terms of the synthesis by Fenton and coworkers of a series of macrocycles containing a 2,5-substituted pyrrole moiety 93-98 [50, 55, 56]. 

Ammoiua N-donor Ligands Macrocyclic Ligands P-donor Ligands S-donor Ligands Water O-donor Ligands. 

L. J. McClure and P. C. Ford, j. Phys. Chem., 96,6640 (1992). Ligand Macrocycle Effects on the Photophysical Properties of Rhodium(lll) Complexes. A Detailed Investigation of as-and tra s-Dicyano(l,4,8,l l-tetraazacyclotetradecane)rhodium(III) and Related Species. 

All known X-ray diffraction data indicate that in penta-coordinated pyramidal vanadium chelates the vanadium atom lies out of the basal plane of the ligand macrocycle, i,e.j the plane of the four pyrrole nitrogen atoms. The distance from vanadium... 

While incorporating a second ring in the enediyne complex reduces the c-d distance between the acetylenic branches, conformational changes may alter the situation with respect to the activation barrier of the Bergman cyclization. The ligand, macrocyclic bipyridyl enediyne 3.882, was synthesized in two steps [398, 399] by the condensation of dibromide 3.870 with 3,3 -dihydroxy-6,6 -dimethyl-2,2 -bipyridyl 3.881 (Scheme 3.120) [24a, 400]. 

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