Structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (+/-)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid

Article abstract of DOI:10.1007/BF01199525

The crystal structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid (1) and of (+/-)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid (2) have been solved by X-ray methods.They are built up in a similar way to centrosymmetric dimers of hydrogen-bonded molecules.The orientation of the substituents around the central C-C bond in both molecules fulfills the requirement for the least spatial hindrance.The observed shift of the v_OH stretching frequencies from 3312(1), 3346(2) cm^-1 in solid to 3408(1), 3450(2), in diluted (10^-3 M) tetrachloromethane solution, indicates the formation of intramolecular hydrogenbonded species.