Extended Assemblies of Ru(bpy)(CO)2X2 (X = Cl, Br, I) Molecules Linked by 1,4-Diiodotetrafluoro-Benzene (DITFB) Halogen Bond Donors

Abstract

The ruthenium carbonyl compounds, Ru(bpy)(CO)2X2 (X = Cl, Br or I) act as neutral halogen bond (XB) acceptors when co-crystallized with 1,4-diiodotetrafluoro-benzene (DITFB). The halogen bonding strength of the Ru-X⋅⋅⋅I halogen bonds follow the nucleophilic character of the halido ligand. The strongest halogen bond occurs between the chlorido ligand and the iodide atoms of the DITFB. All three halogen bonded complexes form polymeric assemblies in the solid state. In Ru(bpy)(CO)2Cl2⋅DITFB (1) and in Ru(bpy)(CO)2Br2⋅DITFB (2) both halido ligands are halogen bonded to only one DITFB donor. In Ru(bpy)(CO)2I2⋅DITFB (3) only one of the halido ligands is involved in halogen bonding acting as ditopic center for two DITFB donors. The polymeric structures of 1 and 2 are isomorphic wave-like single chain systems, while the iodine complexes form pairs of linear chains attached together with weak F⋅⋅⋅O≡C interactions between the closest neighbors. The stronger polarization of the iodide ligand compared to the Cl or Br ligands favors nearly linear C-I⋅⋅⋅I angles between the XB donor and the metal complex supporting the linear arrangement of the halogen bonded chain.

A Novel Halogen Bond Acceptor: 1-(4-Pyridyl)-4-Thiopyridine (PTP) Zwitterion

“…The relative strength of XB is often described using the halogen bonding interaction ratio, R XB , which is defined as R XB = d XB /(X vdW + B vdW ) (d XB is the distance between a halogen atom X and the acceptor atom B in Å). Typically, Bondi vdW radii are used for both X vdW and B vdW ) [43][44][45][46][47][48]. A smaller value of R XB indicates stronger XB strength.…”

Crystal engineering strategies towards halogen-bonded metal–organic multi-component solids: salts, cocrystals and salt cocrystals

“…These metal complexes were also used as halogen bond acceptors in order to study cocrystallisation with 14tfib. 93 In cocrystals with chloride (Fig. 11e) and bromide ligands, the molecules were connected into zig-zag chains by I⋯X-Ru (X = Cl, Br) halogen bonds, while in the cocrystal with iodide ligands, these ligands were involved in halogen bonding as This journal is © The Royal Society of Chemistry 2021 ditopic acceptor sites leading to a nearly linear molecular chain.…”

The Stoichiometry of TCNQ-Based Organic Charge-Transfer Cocrystals

“…There are many papers related to charge transfer cocrystals published in several special issues of the journal Crystals covering different aspects, including donor-acceptor packing type of co-crystals [43,44], hydrogen-bonded co-crystals [45,46], conducting and superconducting co-crystals [47,48], etc. However, it is still worth discussing the role of stoichiometry between donor and acceptor in co-crystals.…”