engleski

Non-merohedral twinning in the structure of rac-NN'-bis(oxalyl valinol)

A twinned crystal is an aggregate in which different domains are joined together according to a specific symmetry operation. In the case of merohedral twinning this symmetry operation belongs to the supergroup of the space group of the crystal, but not in the case of non-merohedral twins. Thus, non-merohedral twin can be easily recognized on a diffraction pattern. The title compound shows twinning which can be detected even by point detector during the data collection. The title compound (1) crystallizes as non-merohedrical twin in the triclinic space group P-1 (2). The twin law is a 180° rotation around b axes of the monoclinic supercell. The analysis of twinning law was by use of the program ROTAX[1]. Data collection was also performed using a CCD detector to resolve the problem of twinning (3). The structure was solved and refined in P-1 space group.

twinning; hydrogen-bonding

nije evidentirano