名称:
Structures of threo(RR,SS) diethyl ester of 2-hydroxy-1,2-diphenylethylphosphonic acid and (�)diethyl ester of (1-hydroxycyclopentyl)(2-methylphenyl)methylphosphonic acid
摘要:
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 nu(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 hydrogen-bonded species.