Potential energy curves for cation-pi interactions: off-axis configurations are also attractive.
Accurate potential energy surfaces for benzene.M complexes (M = Li+, Na+, K+, and NH4+) are obtained using coupled-cluster theory through perturbative triple excitations, CCSD(T). Our computations show that off-axis cation-pi interactions, where the cation is not directly above the aromatic ring, can be favorable and may influence molecular recognition. Even perpendicular, side-on interactions retain 18-32% of their pi-face interaction energy in the gas phase, making their bond strengths comparable to hydrogen bonds in the gas phase. Solvent effects have been explored for each complex using the polarizable continuum model.
Marshall
Michael S
MS
Center for Computational Molecular Science and Technology, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
Steele
Ryan P
RP
Thanthiriwatte
Kanchana S
KS
Sherrill
C David
CD
D000465:Algorithms; D001554:Benzene / Q000737:chemistry*; D002414:Cations, Monovalent / Q000737:chemistry; D002725:Chloroform / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D008956:Models, Chemical; D011188:Potassium / Q000737:chemistry*; D011789:Quantum Theory; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012964:Sodium / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
D002414:Cations, Monovalent; D000644:Quaternary Ammonium Compounds; D012997:Solvents; D014867:Water; D002725:Chloroform; D008094:Lithium; D012964:Sodium; D001554:Benzene; D011188:Potassium