The first Fe(II) complex bearing end-to-end dicyanamide as a double bridging ligand : crystallography study and Hirshfeld surface analysis; completed with a CSD survey

The authors are indebted to the Algerian DG-RSDT (Direction Générale de la Recherche Scientifique et du Développement Technologique) and Université Ferhat Abbas Sétif 1. M.M. is grateful to Ferdowsi University of Mashhad Research Council for their financial support of this work.Two new polymeric, one and two-dimensional compounds [Fe(dmbpy) (μ1,5-dca)2] ( 1 ) and [Fe(4,4′-bpy) (μ1,5-dca)2].0.24(4,4′-bpy).0.5(EtOH) ( 2 ), in which dmbpy = 5,5′-dimethyl-bipyridine, dca = dicyanamide and 4,4′-bpy = 4,4′-bipyridine, has been synthesized under solvothermal conditions and fully characterized by elemental analysis, FT-IR spectroscopy and X-ray single crystal diffraction. Compound 1 , with a rare coordination environment, is the only well-known example in which end-to-end double bridged dca ligands and a bidentate bulky aromatic ligand (dmbpy) are coordinated simultaneously to the iron center. Structural analysis of compound 2 showed it is a novel two-dimensional coordination polymer, constructed from repetition of 4,4′-bpy and dca as a bidentate bridging ligand. Changing the co-ligand to 4,4′-bpy, lead to completely different structure geometry and network, which confirms the substantial effect of co-ligand. Furthermore, Hirshfeld surfaces analyses have been performed to help understand the packing.PostprintPeer reviewe