title: The stacking interactions of bipyridine complexes: the influence of the metal ion type on the strength of interactions.
abstract: The strength of the stacking interactions in the bipy complexes of nickel, palladium, and platinum, [M(CN)2 bipy]2 (M = Ni, Pd, Pt), was calculated using the ωB97xD/def2-TZVP method. The results show that for all considered geometries, interactions are the strongest for platinum, and weakest for nickel complexes, as a result of higher dispersion contributions of platinum over the palladium and nickel complexes. It was also shown that strength of interactions considerably rises with an increase of the stacking overlap area. As a consequence of the favorable electrostatic term, the strength of interactions also rises when metal atom and cyano ligands are involved in the overlap with bipy ligand. The strongest interaction was calculated in the platinum complex, for the geometry that has overlap of metal and cyano ligands with bipy ligand with an energy of -39.80 kcal mol(-1). The energies for similar geometries of palladium and nickel complexes are -34.60 and -32.45 kcal mol(-1). These energies, remarkably, exceed the strength of the stacking interactions between organic aromatic molecules. These results can be of importance in all systems with stacking interactions, from materials to biomolecules.
authors.affiliation: Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.|Innovation Center, Department of Chemistry, Studentski trg 12-16, 11000, Belgrade, Serbia.
authors.forename: Dušan N
authors.initials: DN
authors.lastname: Sredojević
authors.affiliation: Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.|Innovation Center, Department of Chemistry, Studentski trg 12-16, 11000, Belgrade, Serbia.
authors.forename: Predrag V
authors.initials: PV
authors.lastname: Petrović
authors.affiliation: Institute of Chemistry, Technology and Metallurgy, Njegoseva 12, University of Belgrade, P.O.B. 473, 11001, Belgrade, Serbia.
authors.forename: Goran V
authors.initials: GV
authors.lastname: Janjić
authors.affiliation: Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar.
authors.forename: Edward N
authors.initials: EN
authors.lastname: Brothers
authors.affiliation: Department of Chemistry, Texas A&M University College Station, Texas, TX, 77843-3255, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Hall
authors.affiliation: Department of Chemistry, Texas A&M University at Qatar, P.O. Box 23874, Doha, Qatar. snezana.zaric@qatar.tamu.edu.|Department of Chemistry, University of Belgrade, Studentski trg 12-16, Belgrade, Serbia. snezana.zaric@qatar.tamu.edu.
authors.forename: Snežana D
authors.initials: SD
authors.lastname: Zarić
keywords: Bipy complexes; DFT calculations; Interaction energy; Stacking interactions