Rational design of a macrocycle-based chemosensor for anions

Dey, Kalpana R.; Wong, Bryan M.; Hossain, Md. Alamgir

doi:10.1016/j.tetlet.2010.01.004

Cited by 44 publications

(26 citation statements)

References 27 publications

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“…The observed binding constants broadly reflect the influence of relative basicity of the anions. 27 However, the higher binding constants of both receptors for HSO 4 − as compared to the corresponding values for SO 4 2− were somewhat unanticipated, although SO 4 2− is more basic than HSO 4 − and has a higher charge. Such a discrepancy could be attributed to acid-base interactions of the central amine group of L1 or L2 with the acidic HO group of HSO 4 − , 28 providing a secondary interaction of N + ⋯H-O that was also verified by DFT calculations (discussed in later).…”

Section: Resultsmentioning

confidence: 95%

Synthesis and anion binding studies of tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors: proton transfer-induced selectivity for hydrogen sulfate over sulfate

et al. 2015

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Tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors, tris([(4-cyanophenyl)amino]propyl)urea (L1) and tris([(4-cyanophenyl)amino]propyl)thiourea (L2), have been synthesized and their anion binding properties have been investigated for halides and oxoanions. As investigated by 1H NMR titrations, each receptor binds an anion with a 1:1 stoichiometry via hydrogen-bonding interactions (NH⋯anion), showing the binding trend in the order of F− > H2PO4− > HCO3− > HSO4− > CH3COO− > SO42− > Cl− > Br− > I in DMSO-d6. The interactions of the receptors were further studied by 2D NOESY, showing the loss of NOESY contacts of two NH resonances for the complexes of F−, H2PO4−, HCO3−, HSO4− or CH3COO− due to the strong NH⋯anion interactions. The observed higher binding affinity for HSO4− than SO42− is attributed to the proton transfer from HSO4− to the central nitrogen of L1 or L2 which was also supported by the DFT calculations, leading to the secondary acid-base interactions. The thiourea receptor L2 has a general trend to show a higher affinity for an anion as compared to the urea receptor L1 for the corresponding anion in DMSO-d6. In addition, the compound L2 has been exploited for its extraction properties for fluoride in water using a liquid-liquid extraction technique, and the results indicate that the receptor effectively extracts fluoride from water showing ca. 99% efficiency (based on L2).

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Section: Resultsmentioning

confidence: 95%

Synthesis and anion binding studies of tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors: proton transfer-induced selectivity for hydrogen sulfate over sulfate

et al. 2015

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“…This binding trend is consistent with the results reported by Beer and coworkers for triazolium-containing zinc(II) metalloporphyrins, 25 and by us with macrocycle-based receptors appended with dansyl groups. 37 However, an opposite trend was observed with a macrocycle-based copper(II) complex, where the size complementarily dominated over charge density. 30 1 was also tested for other anions including sulfate, phosphate, acetate, cyanide, benzoate, hydroxide, pyrophosphate and citrate in CH 3 CN.…”

Section: Resultsmentioning

confidence: 99%

Colorimetric and optical discrimination of halides by a simple chemosensor

et al. 2015

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A thiophene-based tripodal copper(II) complex has been synthesized as a new colorimetric and optical chemosensor for naked-eye discrimination of halides in acetonitrile and an acetonitrile-water mixture. The binding interactions of the new receptor with several anions were analyzed by UV-Vis titrations, electrospray ionization mass spectrometric (ESI-MS) experiments and density functional theory (DFT) calculations. The results from UV-Vis titrations indicate that the coordinative unsaturated copper(II) complex strongly binds a halide at its vacant copper(II) centre via a metal-ligand bond forming a 1:1 complex, exhibiting binding affinities in the order of fluoride > chloride > bromide > iodide. The interactions of the receptor with halides were further confirmed by ESI-MS, showing a distinct signal corresponding to a 1:1 complex for each halide, suggesting that the noncovalent interactions also exist in the gas phase. In addition, time-dependent DFT (TD-DFT) calculations were also carried out to understand the excited-state properties of the chemosensor complexes. A detailed analysis of the TD-DFT calculations shows a consistent red-shift in the first optically-allowed transition, consistent with the observed colorimetric experiments.

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“…Although the B3LYP hybrid functional produces accurate band gaps, it still fails completely for noncovalent interactions. [26][27][28][29][30][31][32][33][34][35][36][37][38][39] The reason for this failure is that many DFT approximations (including B3LYP) do not accurately account for correlation effects describing the instantaneous multipole/induced multipole charge fluctuations between molecular surfaces. As a result, standard B3LYP-geometry optimizations on noncovalently interacting systems can typically lead to unbound clusters and dissociation of adsorbed species.…”

Section: Introductionmentioning

confidence: 99%

Self-assembled cyclic oligothiophene nanotubes: Electronic properties from a dispersion-corrected hybrid functional

Wong

2011

Phys. Rev. B

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The band structure and size scaling of electronic properties in self-assembled cyclic oligothiophene nanotubes are investigated using density functional theory. In these unique tubular aggregates, the π -π stacking interactions between adjacent monomers provide pathways for charge transport and energy migration along the periodic one-dimensional nanostructure. In order to simultaneously describe both the π -π stacking interactions and the global electronic band structure of these nanotubes, we utilize a dispersion-corrected Becke three-parameter Lee-Yang-Parr-D (B3LYP-D) hybrid functional in conjunction with all-electron basis sets and one-dimensional periodic boundary conditions. Based on our B3LYP-D calculations, we present simple analytical formulae for estimating the fundamental band gaps of these unique nanotubes as a function of size and diameter. Our results on these molecular nanostructures indicate that all of the oligothiophene nanotubes are direct-gap semiconductors with band gaps ranging from 0.9 to 3.3 eV, depending on tube diameter and oligothiophene orientation. These nanotubes have cohesive energies of up to 2.43 eV per monomer, indicating future potential use in organic electronic devices due to their tunable electronic band structure and high structural stability.

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Rational design of a macrocycle-based chemosensor for anions

Cited by 44 publications

References 27 publications

Synthesis and anion binding studies of tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors: proton transfer-induced selectivity for hydrogen sulfate over sulfate

Synthesis and anion binding studies of tris(3-aminopropyl)amine-based tripodal urea and thiourea receptors: proton transfer-induced selectivity for hydrogen sulfate over sulfate

Colorimetric and optical discrimination of halides by a simple chemosensor

Self-assembled cyclic oligothiophene nanotubes: Electronic properties from a dispersion-corrected hybrid functional

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