Co a3 BC

The ligand, l,l,l-tris(aminomethyl)ethane (tame) is a typical tripod ligand and coordinates facially to a cobalt(III) ion. The hexaniobate ion, NbeOfg (Fig. 5.13), is known to function as a bulky terdentate ligand Shimura et al. prepared a few complexes of the /ac(A)-[Co(A3)(BC)d] type, where A3 represents a terdentate ligand. 

The CD spectral data of the (—)j89-glycinato complex is cited in Table 5.6. The so-called additivity rule of the configurational and vidnal contributions permitted to find that the configurational curves for the diastereomeric complexes are similar to the CD curve for the enantiomeric glycinato complex. 

As a reagent for the terdentate ligand, sodium hydrogenhexaniobate Na7HNbgOi9 15 H2O was used The action of a neutralized solution of hexaniobate on aqueous 

The CD s ctral data of the less soluble complexes are cited in Table 5.6. In contrast to the tame complexes, the CD spectra of the hexaniobato complexes deviate considerably from the additivity rule. 

Since the 1,4,7-triaracyclononane ligand, NHCH2CH2NHCH2CH2NHCH2CH2 (tacn), coordinates facially in an octahedral complex, it serves to prepare the c(A)-[Co(A3)(BC) d] complexes. Using this ligand, glycinate and a variety of uni-dentates, various complexes were synthesized 

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