Effects of Heteroatoms on Aromatic π−π Interactions: Benzene−Pyridine and Pyridine Dimer

Citations Over TimeTop 1% of 2009 papers

Abstract

Heteroatoms are found in many noncovalent complexes which are of biological importance. The effect of heteroatoms on pi-pi interactions is assessed via highly accurate quantum chemical computations for the two simplest cases of interactions between aromatic molecules containing heteroatoms, namely, benzene-pyridine and pyridine dimer. Benchmark quality estimated coupled-cluster through perturbative triples [CCSD(T)] binding energies are computed near the complete basis set limit. Comparisons to the benzene dimer are made to determine the contributions from heteroatoms. The presence of a heteroatom reduces the spatial extent of the pi-electron cloud and polarizability of pyridine as compared to benzene. As a result, the magnitude of the dispersion, exchange, and induction interactions in benzene-pyridine and pyridine dimer is generally reduced as compared to those for the benzene dimer. Benzene-pyridine and pyridine dimer bind more strongly than the benzene dimer in several configurations, and in contrast to the benzene dimer, parallel-displaced configurations can be significantly preferred over T-shaped configurations. Hydrogens para to a heteroatom are more effective "pi-hydrogen bond" donors, but aromatic rings with heteroatoms are worse "pi-hydrogen bond" acceptors.

Related Papers

• → σ Aromaticity Dominates in the Unsaturated Three‐Membered Ring of Cyclopropametallapentalenes from Groups 7–9: A DFT Study(2015)41 cited
• → Adaptive σ‐Aromaticity in an Unsaturated Three‐Membered Ring(2020)21 cited
• → Are nucleus-independent (NICS) and 1H NMR chemical shifts good indicators of aromaticity in π-stacked polyfluorenes?(2006)34 cited
• → DERIVATIVES OF STEROIDS WITH CONDENSED HETEROCYCLES(1967)23 cited
• → Literature Survey Part C: Heterocycle Synthesis(2012)2 cited