Elucidating the mechanism of binding of chromate to cucurbit[6]uril: a DFT study

Sundararajan, Mahesh; Ghosh, Swapan K.

doi:10.1007/s10847-011-0008-5

Cited by 10 publications

(8 citation statements)

References 21 publications

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“…were found to make stable complexes with CB[6]. Further, Ghosh and co-workers , studied complexation of CB[6] with halide ion and solvated chromate ion. The current study becomes more relevant as cucurbiturils have already been synthesized.…”

Section: Introductionmentioning

confidence: 99%

Cucurbit[6]uril: A Possible Host for Noble Gas Atoms

2015

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Density functional and ab initio molecular dynamics studies are carried out to investigate the stability of noble gas encapsulated cucurbit[6]uril (CB[6]) systems. Interaction energy, dissociation energy and dissociation enthalpy are calculated to understand the efficacy of CB[6] in encapsulating noble gas atoms. CB[6] could encapsulate up to three Ne atoms having dissociation energy (zero-point energy corrected) in the range of 3.4-4.1 kcal/mol, whereas due to larger size, only one Ar or Kr atom encapsulated analogues would be viable. The dissociation energy value for the second Ar atom is only 1.0 kcal/mol. On the other hand, the same for the second Kr is -0.5 kcal/mol, implying the instability of the system. The noble gas dissociation processes are endothermic in nature, which increases gradually along Ne to Kr. Kr encapsulated analogue is found to be viable at room temperature. However, low temperature is needed for Ne and Ar encapsulated analogues. The temperature-pressure phase diagram highlights the region in which association and dissociation processes of Kr@CB[6] would be favorable. At ambient temperature and pressure, CB[6] may be used as an effective noble gas carrier. Wiberg bond indices, noncovalent interaction indices, electron density, and energy decomposition analyses are used to explore the nature of interaction between noble gas atoms and CB[6]. Dispersion interaction is found to be the most important term in the attraction energy. Ne and Ar atoms in one Ng entrapped analogue are found to stay inside the cavity of CB[6] throughout the simulation at 298 K. However, during simulation Ng2 units in Ng2@CB[6] flip toward the open faces of CB[6]. After 1 ps, one Ne atom of Ne3@CB[6] almost reaches the open face keeping other two Ne atoms inside. At lower temperature (77 K), all the Ng atoms in Ngn@CB[6] remain well inside the cavity of CB[6] throughout the simulation time (1 ps).

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Section: Introductionmentioning

confidence: 99%

Cucurbit[6]uril: A Possible Host for Noble Gas Atoms

2015

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“…Quantum chemical methodology has recently become an important tool in the study of supramolecular host–guest complexes. − The various components of the methodology have gradually improved, and more accurate results are possible today. Advances in density functional theory are, of course, of great importance here, but also important is the development of various corrections, such as dispersion and free energy corrections. , …”

Section: Introductionmentioning

confidence: 99%

Mixed Explicit–Implicit Solvation Approach for Modeling of Alkane Complexation in Water-Soluble Self-Assembled Capsules

et al. 2018

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The host-guest binding properties of a water-soluble resorcinarene-based cavitand are examined using density functional theory methodology. Experimentally, the cavitand has been observed to self-assemble in aqueous solution into both 1:1 and 2:1 host/guest complexes with hydrophobic guests such as n-alkanes. For n-decane, equilibrium was observed between the 1:1 and 2:1 complexes, while 1:1 complexes are formed with shorter n-alkanes and 2:1 complexes are formed with longer ones. These findings are used to assess the standard quantum chemical methodology. It is first shown that a rather advanced computational protocol (B3LYP-D3(BJ)/6-311+G(2d,2p) with COSMO-RS and quasi-rigid-rotor-harmonic-oscillator) gives very large errors. Systematic examination of the various elements of the methodology shows that the error stems from the implicit solvation model. A mixed explicit-implicit solvation protocol is developed that involves a parametrization of the hydration free energy of water such that water cluster formation in water is predicted to be thermoneutral. This new approach is demonstrated to lead to a major improvement in the calculated binding free energies of n-alkanes, reproducing very well the 1:1 versus 2:1 host/guest binding trends.

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“…Studies involving complexation of CB [6] with halide ion and solvated chromate ion were investigated by Ghosh and co-workers. 62,63 In view of the potential use of CB [6] as a host to different gases, the present study attempts to determine relative stability of different gases encapsulated by CB [6]. In this way, the selectivity in gas adsorption by CB [6] over a large spectrum of gas molecules can be predicted.…”

Section: ■ Introductionmentioning

confidence: 99%

“…In fact, Kim et al showed that CB[6] adsorbs CO 2 selectively over CO and CH 4 in the solid state. Studies involving complexation of CB[6] with halide ion and solvated chromate ion were investigated by Ghosh and co-workers. , …”

Section: Introductionmentioning

confidence: 99%

Selectivity in Gas Adsorption by Molecular Cucurbit[6]uril

et al. 2016

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The relative preference in adsorption among 19 common gas molecules, namely, C 2 H 2 , C 2 H 4 , C 2 H 6 , CH 4 , X 2 , HX (X = F, Cl, Br), CO 2 , CS 2 , CO, H 2 , H 2 O, H 2 S, N 2 , NO 2 , and NO within the cavity of cucurbit[6]uril (CB[6]) is investigated via density functional theory computations. Energies associated with the dissociation of gas@CB[6] producing CB[6] and gas molecules show the order of the efficacy to be encapsulated within CB[6], C 2 H 2 @CB[6] being the most viable system. However, the dissociation free energy change implies that CB[6] is most efficient in accommodating Cl 2 followed by C 2 H 2 among the considered gas molecules. In general, guest molecules having large surface contact with the host and/or high polarizability and/or having acidic hydrogen to make hydrogen bond with >CO show larger propensity to be encapsulated within CB[6] cavitand. Functionalized CB[6] are better candidates for gas adsorption than CB [6]. However, the nature of functionalization needed to improve the adsorption ability varies with the change in the guest molecule. While full −C 2 H 5 substitution improves C 2 H 2 and CO 2 adsorption ability of CB[6] the most, the −CN functionalized CB [6] is the best candidate to encapsulate C 2 H 4 and C 2 H 6 among the studied −OH, −C 2 H 5 , and −CN substituted analogues. The interaction is mostly of van der Waals type, except in the cases of C 2 H 2 , H 2 O, H 2 S, and HX (X = F, Cl, Br), in which both the electrostatic and dispersion contributions are important owing to the interaction between acidic hydrogen of these guest molecules and oxygen centers of the host moiety.

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Elucidating the mechanism of binding of chromate to cucurbit[6]uril: a DFT study

Cited by 10 publications

References 21 publications

Cucurbit[6]uril: A Possible Host for Noble Gas Atoms

Cucurbit[6]uril: A Possible Host for Noble Gas Atoms

Mixed Explicit–Implicit Solvation Approach for Modeling of Alkane Complexation in Water-Soluble Self-Assembled Capsules

Selectivity in Gas Adsorption by Molecular Cucurbit[6]uril

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