REACTION BETWEEN (SALEN)TICL2 AND CHIRAL ALPHA-HYDROXY CARBOXYLIC-ACIDS

Coordination of a bidentate ligand to a (salen)Ti(IV) complex causes c onversion of the pseudoplanar salen ligand, which binds the Ti with me r (octahedral) geometry, into a helical ligand, which has fac geometry about the metal. If either the salen or the bidentate ligand contains a resolved, stereogenic center, the resulting he cal complex is chira l. X-ray crystallographic data correlate the sense of helical; deforma tion with substitution configuration either of the salen or of the a-h ydroxy carboxylato ligands. These X-ray data can be quantatitively cor related with circular dichroism (CD) spectra, which demonstrates that the simple spectroscopic technique can provide an acceptable means of determining the magnitude of the helical deformation of fac-salen addu cts, according to chiral exciton theory.synlp; 136q.