title: Parallel interactions at large horizontal displacement in pyridine-pyridine and benzene-pyridine dimers.
abstract: A study of crystal structures from the Cambridge Structural Database (CSD) and DFT calculations reveals that parallel pyridine-pyridine and benzene-pyridine interactions at large horizontal displacements (offsets) can be important, similar to parallel benzene-benzene interactions. In the crystal structures from the CSD preferred parallel pyridine-pyridine interactions were observed at a large horizontal displacement (4.0-6.0 Å) and not at an offset of 1.5 Å with the lowest calculated energy. The calculated interaction energies for pyridine-pyridine and benzene-pyridine dimers at a large offset (4.5 Å) are about 2.2 and 2.1 kcal mol(-1), respectively. Substantial attraction at large offset values is a consequence of the balance between repulsion and dispersion. That is, dispersion at large offsets is reduced, however, repulsion is also reduced at large offsets, resulting in attractive interactions.
authors.affiliation: Innovation center of the Department of Chemistry, University of Belgrade, Studentski trg 12-16, 11000 Belgrade, Serbia.
authors.forename: Dragan B
authors.initials: DB
authors.lastname: Ninković
authors.forename: Jelena M
authors.initials: JM
authors.lastname: Andrić
authors.forename: Snežana D
authors.initials: SD
authors.lastname: Zarić
mesh_terms: D001554:Benzene / Q000737:chemistry*; D003198:Computer Simulation; D062126:Databases, Chemical; D019281:Dimerization; D006860:Hydrogen Bonding; D008958:Models, Molecular; D011725:Pyridines / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D011725:Pyridines; D001554:Benzene; C023666:pyridine