title: An ab initio study on the concerted interaction between chalcogen and pnicogen bonds.
abstract: We analyzed cooperation between chalcogen-bonding and pnicogen-bonding interactions in XHS···NCH2P···NCY (X = F, Cl; Y = H, OH, NH2, CN and NC) complexes at the MP2/6-311++G** level. These effects were studied in terms of geometric and energetic properties, harmonic frequencies, and nuclear magnetic resonance (NMR). A cooperativity factor was adopted to measure the cooperativity between the two types of interaction in triads based on S-X and P-CN stretching frequencies. The size of the cooperative effect in each complex depends on the strength of S···N and P···N interactions. It is largest for FHSN⋯CH2P⋯NCNH2 and smallest for ClHS⋯NCH2P⋯NCCN and ClHS⋯NCH2P⋯NCNC complexes. The total spin-spin coupling constants across the chalcogen and pnicogen bonds in the ternary complexes are always larger than those in the binary systems. This trend can be also interpreted as a cooperative effect between chalcogen and pnicogen bond interactions. The enhancing mechanism was analyzed in terms of electron redistribution effects in XHS···NCH2P···NCY complexes.
authors.affiliation: Department of Chemistry, Faculty of Science, Imam Ali University, Tehran, Iran.
authors.forename: Bahman Mohammadian
authors.initials: BM
authors.lastname: Asiabar
authors.forename: Mehdi D
authors.initials: MD
authors.lastname: Esrafili
authors.forename: Fariba
authors.initials: F
authors.lastname: Mohammadian-Sabet
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Sobhi
authors.forename: Majid
authors.initials: M
authors.lastname: Javaheri
mesh_terms: D016880:Anisotropy; D047188:Chalcones / Q000737:chemistry*; D004735:Energy Transfer; D009682:Magnetic Resonance Spectroscopy; D062105:Molecular Docking Simulation; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D047188:Chalcones; D010758:Phosphorus; D009584:Nitrogen