No abstract

No abstract

Two crystalline polymorphic forms of DL-a-amino-n-butyric acid have been obtained and have been shown to be identical to the A-form and B-form previously described by Iitaka and coworkers. The two forms differ in heat of solution and in their solubility in water. We find that for the A-form at 298 K, AH: = 374 cal mol-l, AG; = 1772 cal mol-I and AS; = -4.7 cal K-' mol-' and for the B-form AH," = 1653 cal mol-l, AG; = 1883 cal mol-' and AS," = -0.8 cal K-l mol-l. Although the B-form is the stable form at 298 K, it is predicted from the above measurements that the A-form should be the stable form above -326 K.

Fermi resonance between a broad v (OD) fundamental and a sharp 28(ODO) overtone is postulated to be the cause of the verydifferent appearance of the v(0H) and v(OD) i.r. absorption bands of HCrO, and DCrO,.

No abstract