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Orabi EA, Lamoureux G. Cation-π Interactions between Quaternary Ammonium Ions and Amino Acid Aromatic Groups in Aqueous Solution. J Phys Chem B 2018; 122:2251-2260. [PMID: 29397727 DOI: 10.1021/acs.jpcb.7b11983] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cation-π interactions play important roles in the stabilization of protein structures and protein-ligand complexes. They contribute to the binding of quaternary ammonium ligands (mainly RNH3+ and RN(CH3)3+) to various protein receptors and are likely involved in the blockage of potassium channels by tetramethylammonium (TMA+) and tetraethylammonium (TEA+). Polarizable molecular models are calibrated for NH4+, TMA+, and TEA+ interacting with benzene, toluene, 4-methylphenol, and 3-methylindole (representing aromatic amino acid side chains) based on the ab initio MP2(full)/6-311++G(d,p) properties of the complexes. Whereas the gas-phase affinity of the ions with a given aromatic follows the trend NH4+ > TMA+ > TEA+, molecular dynamics simulations using the polarizable models show a reverse trend in water, likely due to a contribution from the hydrophobic effect. This reversed trend follows the solubility of aromatic hydrocarbons in quaternary ammonium salt solutions, which suggests a role for cation-π interactions in the salting-in of aromatic compounds in solution. Simulations in water show that the complexes possess binding free energies ranging from -1.3 to -3.3 kcal/mol (compared to gas-phase binding energies between -8.5 and -25.0 kcal/mol). Interestingly, whereas the most stable complexes involve TEA+ (the largest ion), the most stable solvent-separated complexes involve TMA+ (the intermediate-size ion).
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Affiliation(s)
- Esam A Orabi
- Department of Chemistry and Biochemistry and Centre for Research in Molecular Modeling (CERMM), Concordia University , 7141 Sherbrooke Street West, Montréal, Québec H4B 1R6, Canada
| | - Guillaume Lamoureux
- Department of Chemistry and Biochemistry and Centre for Research in Molecular Modeling (CERMM), Concordia University , 7141 Sherbrooke Street West, Montréal, Québec H4B 1R6, Canada
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Theoretical study of the influence of cation-π and anion-π interactions on some NMR data of borazine complexes. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.04.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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RASEKH MAHTABFATHI. THEORETICAL INVESTIGATION ON THE STRUCTURE AND PROPERTIES OF ALUMAZINE⋯M COMPLEXES ( M = Li+, Na+, K+, Be2+, Mg2+, AND Ca2+). JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2013. [DOI: 10.1142/s0219633613500338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The nature of alumazine⋯M ( M = Li+ , Na+ , K+ , Be2+ , Mg2+ , AND Ca2+ ) interactions was studied by ab initio calculations. The interaction energies were calculated at MP2/6-311++G(d,p)//B3LYP/6-311++G(d,p) level. The calculations suggest that the size and charge of cation are two important factors that affect the interaction energy, charge transfer values and the variation in aromaticity of alumazine ring upon complexation. The theory of atoms in molecules (AIM) and natural bond orbital (NBO) analyses of complexes indicate that the variation of densities and the extent of charge shifts upon complexation correlate well with the obtained interaction energies. Finally, nucleus independent chemical shift (NICS) method was applied for evaluating the variation in aromaticity of alumazine ring upon complexation.
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Affiliation(s)
- MAHTAB FATHI RASEKH
- Department of Chemistry, Sharif University of Technology, Azadi Avenue, Tehran, Iran
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Ebrahimi A, Habibi Khorassani SM, Behazin R, Rezazadeh S, Azizi A, Karimi P. Relationship between cation–π and anion–π interactions: individual binding energies in the π–Mz+–π–X−–π system. Mol Phys 2013. [DOI: 10.1080/00268976.2013.796417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Effect of stepwise microhydration on the methylammonium···phenol and ammonium···phenol interaction. J Mol Model 2012; 19:1985-94. [DOI: 10.1007/s00894-012-1579-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Accepted: 08/21/2012] [Indexed: 10/27/2022]
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Ghiasi R. Theoretical investigation of the structure and properties of H2B=NH2...M n+, HB≡NH...M n+, and Borazine...M n+ complexes (M = Alkaline and Earth Alkaline Metals). RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2011. [DOI: 10.1134/s0036024411120272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Yi HB, Lee HM, Kim KS. Interaction of Benzene with Transition Metal Cations: Theoretical Study of Structures, Energies, and IR Spectra. J Chem Theory Comput 2009; 5:1709-17. [PMID: 26609861 DOI: 10.1021/ct900154x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hai-Bo Yi
- College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China, Department of Chemistry and Center for Basic Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea, and Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Han Myoung Lee
- College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China, Department of Chemistry and Center for Basic Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea, and Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
| | - Kwang S. Kim
- College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China, Department of Chemistry and Center for Basic Sciences, Pohang University of Science and Technology, Pohang 790-784, Korea, and Center for Superfunctional Materials, Department of Chemistry, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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Shi FQ, An JY, Yu JY. Counterion effects on the cation–π interactions between alkaline earth cations and pyrrole. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.theochem.2004.12.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Priyakumar U, Sastry G. Cation-π interactions of curved polycyclic systems: M+ (M=Li and Na) ion complexation with buckybowls. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)01512-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Fukin GK, Lindeman SV, Kochi JK. Molecular structures of cation...pi(arene) interactions for alkali metals with pi- and sigma-modalities. J Am Chem Soc 2002; 124:8329-36. [PMID: 12105914 DOI: 10.1021/ja0203465] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The monovalent cations of Na(+), K(+), Rb(+), and Cs(+) derived from the highly electropositive alkali metals represent prototypical charged spheres that are mainly subject to relatively simple electrostatic and solvation (hydration) forces. We now find that the largest of these Rb(+) and Cs(+) are involved in rather strong cation...pi(arene) interactions when they are suitably disposed with the ambifunctional hexasubstituted benzene C(6)E(6). The ether tentacles (E = methoxymethyl) allow these cations to effect eta(1)-bonding to the benzene center in a manner strongly reminiscent of the classical sigma-arene complexes with positively charged electrophiles where Z(+) = CH(3)(+), Br(+), Cl(+), Et(3)Si(+), etc. The somewhat smaller potassium cation is involved in a similar M(+)...pi(arene) interaction that leads to eta(2)-bonding with the aromatic center in the pi-mode previously defined in the well-known series of silver(I)/arene complexes. We can find no evidence for significant Na(+)... pi(arene) interaction under essentially the same conditions. As such, the sigma-structure of the Rb(+) and Cs(+) complexes and pi-structure of the K(+) complex are completely integrated into the continuum of sigma-pi bondings of various types of electrophilic (cationic) acceptors with arene donors that were initially identified by Mulliken as charge-transfer.
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Affiliation(s)
- Georgy K Fukin
- Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA
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Bartoli S, Roelens S. Binding of acetylcholine and tetramethylammonium to a cyclophane receptor: anion's contribution to the cation-pi interaction. J Am Chem Soc 2002; 124:8307-15. [PMID: 12105911 DOI: 10.1021/ja025884w] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The interaction of the lipophilic cyclophane 1 with several acetylcholine (ACh) and tetramethylammonium (TMA) salts has been investigated in deuteriochloroform to ascertain the influence of the counterion on the cation-pi interaction. Reliable association constants have been measured for 17 salts of commonly used anions; corresponding binding free energies -DeltaG degrees ranged from over 8 kJ mol(-1) down to the limit of detection. The dramatic dependence of the binding energy on the anion showed that the latter takes part in the process with a passive and adverse contribution, which inhibits cation binding even to complete suppression in unfavorable cases. Thermodynamic parameters for the association of 1 with TMA picrate demonstrate that binding is enthalpic in origin, showing a substantial enthalpy gain (DeltaH degrees = -16.7 kJ mol(-1)) and an adverse entropic contribution (DeltaS degrees = -27.9 J mol(-1) K(-1)). A correlation has been found between the "goodness" of anions as binding partners and the solubility of their salts. Conversion of the anion into a more charge-dispersed species, for example, conversion of chloride into dialkyltrichlorostannate, improves cation binding substantially, indicating that charge dispersion is a main factor determining the influence of the anion on the cation-pi interaction. DFT computational studies show that the variation of the binding free energy of TMA with the counterion is closely accounted for by the electrostatic potential (EP) of the ion pair: guest binding appears to respond to the cation's charge density exposed to the receptor, which is determined by the anion's charge density through a polarization mechanism. A value of -DeltaG degrees = 38.6 kJ mol(-1) has been extrapolated for the free energy of binding of TMA to 1 in chloroform but in the absence of a counterion. The transmission of electrostatic effects from the ion pair to the cation-pi interaction demonstrates that host-guest association is governed by Coulombic attraction, as long as factors (steric, entropic, solvation, etc.) other than pure electrostatics are not prevalent.
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Affiliation(s)
- Sandra Bartoli
- CNR, Istituto di Chimica dei Composti Organometallici, Dipartimento di Chimica Organica, Università di Firenze, Polo Scientifico, I-50019 Sesto Fiorentino, Firenze, Italy
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Aschi M, Mazza F, Di Nola A. Cation–π interactions between ammonium ion and aromatic rings: an energy decomposition study. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0166-1280(02)00112-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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