Chiral Aminotroponiminate Zinc Complexes

The enantiomerically pure bridged aminotroponiminates (S,S)- and (R,R)-H2{(iPrATI)2diph}, in which two amino-isopropyl-troponimine moieties are linked by 1,2-(S,S)- or 1,2-(R,R)-diamino-1,2-diphenylethane, have been used as ligands in zinc chemistry. The bimetallic zincmethyl, -ethyl, and phenyl complexes containing the enantiomerically pure bridged aminotroponiminates (S,S)- or (R,R)-{(iPrATI)2diph}2− were prepared by the reaction of ZnR2 (R = Me, Et, Ph) with the neutral ligands. As a result the compounds [(S,S)-{(iPrATI)2diph}(ZnR)2] (R = Me (1), Et (2)) and [(R,R)-{(iPrATI)2diph}(ZnPh)2] (3) were obtained. Moreover, the new ligands (S,S)-H2{((R)-PhCHCH3ATI)2diph} and (R,R)-H2{((R)-PhCHCH3ATI)2diph}, which are diasteromers, were prepared by using (R)-1-amino-1-phenylethane instead of isopropylamine in the ligand synthesis. Reacting these ligands with ZnMe2 resulted in the enantiomerically pure compounds [(S,S)-{((R)-PhCHCH3ATI)2diph}(ZnMe)2] (4) and [(R,R)-{((R)-PhCHCH3ATI)2diph}(ZnMe)2] (5). Compounds 1−5 were investigated by single-crystal X-ray diffraction, showing a distorted trigonal-planar coordination of the zinc atoms.