Rationalization of Noncovalent Interactions within Six New M^II/8-Aminoquinoline Supramolecular Complexes (M^II = Mn, Cu, and Cd): A Combined Experimental and Theoretical DFT Study

Abstract

To examine the influence of the metal ions and their counterions on crystalline networks, we have designed and synthesized six MX 2 /8-aminoquinoline (8-aq) (M = Mn II , Cu II , Cd II and X = Cl − , Br − , I − , NO 3 − , SCN − ) complexes, having the formulas [Mn(8-aq) 2 I 2 ]•(1), 5), and Cd(8-aq) 2 I 2 (6). Single-crystal Xray diffraction analyses showed that all of the complexes have a distorted octahedral geometry, in which each 8-aq molecule acts as a bidentate ligand and coordinates to the central metal ion with its common coordination mode, to form an N,N′ chelating motif. Remarkably, the influence of the counterion on the geometry of the complex is very significant since both I − and SCN − anions are coordinated to the metal ion in compounds 1, 3, and 6, adopting a cis configuration, while a single anion occupies an axial position in compounds 4 and 5 (Cl − and NO 3 − , respectively) and the other counterion is not coordinated. Finally, both Br − anions are not coordinated in the cationic complex 2 (Mn metal center). In all cases, there are extended supramolecular networks due to cooperativity hydrogen-bonding and π−π stacking interactions that play an essential role in the formation and stability of the crystalline materials. The binding energies attributed to the different interactions have been evaluated using DFT calculations.

Surface-grafted lanthanoid complexes of the tungstosilicate polyanion [SiW12O40]4−: a synthetic, structural and computational investigation

“…Finally, the broad band around 3400 cm À1 is assigned to the water molecules and other hydrogen-bonding interactions (Fig. S5b in the supporting information) (Mirzaei, Eshtiagh-Hosseini, Bolouri et al, 2015).…”

Modulation in π⋯π, cation⋯π and C–H⋯H–C interactions varying the counter anions in square planar nickel(II) Schiff base complexes: A combined experimental and theoretical study

“…To evaluate the interactions in the solid state, we have used the crystallographic coordinates. This procedure and level of theory have been successfully used to evaluate similar interactions [65][66][67][68]. The interaction energies were computed by calculating the difference between the energies of isolated monomers and their assembly.…”

New rhenium-tricarbonyl complexes bearing halogen-substituted bidentate ligands: structural, computational and Hirshfeld surfaces studies

“…This method has previously been successfully used to evaluate similar interactions. [52][53][54][55] The interaction energies were computed by calculating the difference between the energies of isolated monomers and their assembly. The interaction energies were corrected for the basis set superposition error (BSSE) using the counterpoise method.…”