T. Asahi et al., OPTICAL-ACTIVITY OF CRYSTALLINE GLUTAMIC ACIDS, Acta crystallographica. Section A, Foundations of crystallography, 52, 1996, pp. 766-769
As the first study on gyro-optical properties of amino acids, temperat
ure dependences of the gyration tensor components of L- and D-glutamic
acids were measured by using the HAUP (high-accuracy universal polari
meter). It was confirmed that the corresponding tensor components of t
he two enantiomers are the same in magnitude but opposite in sign. It
is proposed that r = (rho(C)(0) - rho(S)(0))/rho(C)(0) be defined as t
he 'chirality index', where rho(C)(0) and rho(S)(0) designate rotatory
powers per molecule in a crystal and in a dissolved state in liquid,
respectively. It represents a measure of structural contribution of op
tical activity (OA) in a crystal. This value is 0.992 in glutamic acid
s.