Structural Studies of Racemates and Quasiracemates: Chloro, Bromo, and Methyl Adducts of 2-Phenoxypropionic Acid

Quasiracemic compounds derived from the enantiopure Cl, Br, and CH 3 analogues of 2-phenoxypropanoic acid crystallize to give approximate centrosymmetry supramolecular assemblies. Each quasiracemate forms the anticipated heterodimers via O−H···O carboxyl interactions that lead to two distinct packing motifs in space group P 2 1 with Z ′ = 2 (Cl/Br and Br/CH 3 ) or 8 (Cl/CH 3 and Br/CH 3 ). The Z = 2 quasiracemates are isostructural with ( rac )-Cl and ( rac )-Br, while the Z ′ = 8 structures form molecular patterns that resemble the packing preferences of ( rac )-CH 3 . The Br/CH 3 quasiracemate was retrieved as concomitant polymorphs.