ScienceAsia 28 (2002) : 271-275 |doi: 10.2306/scienceasia1513-1874.2002.28.271

Crystal Structure Determination of 5,6-Dibromoacenaphthene from X-ray Powder Diffraction Data

Nongnuj Jaiboon^*

ABSTRACT: The new crystal structure of 5,6-dibromoacenaphthene has been successfully determined from X-ray powder diffraction data with monoclinic crystals, P2₁/n, a = 7.88(1) A^o, b = 11.64(1) A^o, c = 11.62(1) A^o, Beta =107.09(9)^o, V = 1019.9(1) A^o3 and Z = 4. Individual reflection intensities were extracted by means of Le Bail’s method. The molecular structure of 1 was solved by direct methods and refined using the combination of least-squares and Rietveld methods. The final Rietveld refinement converged to the value of R_p = 0.114, R_wp = 0.155, Bragg-R_f = 5.28 for 8532 data points and 933 extracted reflections collected in the 2^o < 2-zeta < 95^o range. The molecules have an interplanar pi-pi interaction between the acenaphthene planes with the average distance of 3.57(9) A^o. Moreover, the molecular dimer-pairwise packing diagram has an unexpected straight stacking, as opposed to the usual lateral stacking normally occured in 5,6-dihaloacenaphthene.

Download PDF

Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.


*Corresponding author, E-mail: nongnuj.j@chula.ac.th

Received 14 Feb 2001, Accepted 8 Jan 2002