Crystal structure of 9,9-di-ethyl-9 H-fluorene-2,4,7-tricarbaldehyde

Acta Crystallogr E Crystallogr Commun. 2021 Sep 17;77(Pt 10):1029-1032. doi: 10.1107/S2056989021009464. eCollection 2021 Oct 1.

Abstract

The title compound, C20H18O3, crystallizes in the space group P21/c with one mol-ecule in the asymmetric unit of the cell. The fluorene skeleton is nearly planar and the crystal structure is composed of mol-ecular layers extending parallel to the (302) plane. Within a layer, one formyl oxygen atom participates in the formation of a Carene-H⋯O bond, which is responsible for the formation of an inversion symmetric supra-molecular motif of graph set R 2 2(10). A second oxygen atom is involved in an intra-molecular Carene-H⋯O hydrogen bond and is further connected with a formyl hydrogen atom of an adjacent mol-ecule. A Hirshfeld surface analysis indicated that the most important contributions to the overall surface are from H⋯H (46.9%), O⋯H (27.9%) and C⋯H (17.8%) inter-actions.

Keywords: Hirshfeld surface analysis; crystal structure; fluorene derivative; hydrogen bonding; two-dimensional fingerprint plots.