EVIDENCE FOR CORRELATED ROTATION AND DIASTEREOISOMER DISCRIMINATION IN (ETA-4-DIENE)FE(CO)2L COMPLEXES - THE CRYSTAL AND SOLUTION STRUCTURES OF (CYCLOHEXADIENE)FE(CO)2P(ORTHO-TOLYL)3 AND (CYCLOHEPTADIENE)FE(CO)2(+)-PPH2(NEOMENTHYL)

The solid state structure of (cyclohexadiene)Fe(CO)2P(o-tolyl)3 reveals an exo2 conformation for the phosphine. In solution, arene ring exchange in the phosphine and exchange of phosphine between equivalent basal positions of the square pyramid occur at equal rates. In solution, (cycloheptadiene)Fe(CO)2(+)-PPh2(neomenthyl) exhibits a diastereoselection between basal isomers, and crystallizes as a single diastereoisomer which has been structurally characterized.