The absolute stereochemistry of axially chiral 2, 2′-X2-9, 9′-bianthryls (X= COOH, COOMe, and Cl) was determined by X-ray analysis of the (+)-quinidine salt of the diacid to be (M)-(−) or (P)-(+). The M isomers of these compounds showed specific rotations of− 115,− 123, and− 32, respectively, in acetone. The circular dichroism (CD) as well as UV spectra of the two M isomers (X= COOMe and Cl) were investigated with the aid of theoretical ...