On the importance of antiparallel C=O•••C-F interactions in N1-(3-hydroxypropy1)-5-fluorouracilate-Hg(II) complex: A combined X-ray and DFT study

Herein we report the synthesis and X-ray characterization of a neutral mercury(II) complex of composition [Hg(L)(2)](n) (1), [L = N-1-(3-hydroxypropy1)-5-fluorouracilate]. The Hg(II) is bound to the N(3) atoms of both ligands in an essentially linear geometry. Mercury also interacts through short contacts with the 0(4) atoms of the uracil rings. The two bases are almost coplanar. Surprisingly, two hydroxyl groups from two different units are also weakly bound in apical positions. Single-crystal X-ray crystallography showed that the molecular complex aggregates into a coordination polymer. The packing assemblies observed in the solid state have been analysed and studied by means of theoretical DFT calculations. Unprecedented antiparallel C=O center dot center dot center dot C-F interactions are described since they have a strong influence in the crystal packing of the complex. We have also used the Cambridge Structural Database to examine the occurrence of C=O center dot center dot center dot C-F interaction in the solid state of X-ray structures. (C) 2015 Elsevier B.V. All rights reserved.