Öz The crystal structure of saturated bislactam has been determined from three dimensional siııgle crystal X-ray data. The crystals are monolinic, with ımit-cell dimensions a = 43.431(2), b— 7.707(1), c— 13.586(1) Â, B -- 96.35(1)°, space group C2 / c and Z— 8. The structure was solved by dı’rect methods and refined by full-matrix least squares to R — 0.061 for the 3374 independent diffractometer measured reflections. The title compound forms a 1:1 inclusion compound with o-xylne and the molecules have almost perfect C2-symmetry uhich is a non- crys1 allograph ic symmetry.