A versatile tripodal amide receptor for the encapsulation of anions or hydrated anions via formation of dimeric capsules

Article abstract of DOI:10.1021/ic901644h

A bowl-shaped tripodal receptor with an appropriately positioned amide functionality on the benzene platform and electron-withdrawing p-nitrophenyl terminals (L¹) has been designed, synthesized, and studied for the anion binding properties. The single-crystal X-ray crystallography analysis on crystals of L¹ with tetrabutylammonium salts of nitrate (1), acetate (2), fluoride (3), and chloride (4) obtained in moist dioxane medium showed encapsulation of two NO₃^-, [(AcO)₂(H ₂O)₄]^2-, [F₂(H₂O) ₆]2-, and [Cl₂(H₂O)₄]^2- respectively as the anionic guests inside the staggered dimeric capsular assembly of L¹. The p-nitro substitution in the aryl terminals assisted the formation of dimeric capsular assembly of L¹ exclusively upon binding/encapsulating above different guests. Though L¹ demonstrates capsule formation upon anion or hydrated anion complexation for all of the anions studied here, its positional isomer with the o-nitro-substituted tripodal triamide receptor L² selectively formed the dimeric capsular assembly upon encapsulation of [F₂(H₂O)₆] ^2- and noncapsular aggregates in the cases of other anions such as Cl^-, NO^3-, and AcO^-. Interestingly, structural investigations upon anion exchange of the complexes revealed that both isomers have selectivity toward the formation of a [F₂(H₂O) ₆]^2- encapsulated dimeric capsule. In contrast, solution-state ¹H NMR titration studies of L¹ and L ² in DMSO-d₆ with AcO^- indicated 1:3 (host:guest) binding.

Full text of DOI:10.1021/ic901644h

Supporting Information
A versatile tripodal amide receptor for the encapsulation of anions or hydrated
anions via formation of dimeric capsules
M. Arunachalam and Pradyut Ghosh*
Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, 2A & 2B Raja S. C. Mullick Road, Kolkata
700032, India.
E-mail: icpg@iacs.res.in
Contents
Page No.
1.
Figure S1. 1H-NMR spectra of L1 in DMSO-d6 at 25ºC……………………………………………S2
2.
Figure S2. 13C-NMR spectra of L1 in DMSO-d6 at 25ºC…………………………………………...S3
Figure S3. HRMS(ESI) Spectrum of L1…………………………………………………………….S4
Figure S4. 1H-NMR spectra of Complex 1 in DMSO-d6 at 25ºC…………………………………..S5
Figure S5. 13C-NMR spectra of Complex 1 in DMSO-d6 at 25ºC………………………………….S6
Figure S6. 1H-NMR spectra of Complex 2 in DMSO-d6 at 25ºC…………………………………..S7
Figure S7. 13C-NMR spectra of Complex 2 in CDCl3 at 25ºC…………………………………….. S8
Figure S8. 1H-NMR spectra of Complex 3 in DMSO-d6 at 25ºC…………………………………..S9
Figure S9. 13C-NMR spectra of Complex 3 in DMSO-d6 at 25ºC………………………………….S10
Figure S10. 1H-NMR spectra of Complex 4 in DMSO-d6 at 25ºC…………………………………S11
Figure S11. 13C-NMR spectra of Complex 4 in DMSO-d6 at 25ºC………………………………...S12
Figure S12. 19F-NMR spectra of TBA-F in DMSO-d6 at 25ºC……………………………………S13
Figure S13. 19F-NMR spectra of mixture of TBA-F and L1 in DMSO-d6 at 25ºC…………………S14
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S1

Figure S1. 1H-NMR spectra of Complex L1 in DMSO-d6 at 25ºC
S2

Figure S2. 13C-NMR spectra of L1 in DMSO-d6 at 25ºC
S3

Figure S3. HRMS(ESI) spectrum of L1.
S4

Figure S4. 1H-NMR spectra of Complex 1 in DMSO-d6 at 25ºC
S5

Figure S5. 13C-NMR spectrum of Complex 1 DMSO-d6 at 25ºC.
S6

Figure S6. 1H-NMR spectrum of Complex 2 DMSO-d6 at 25ºC.
S7

Figure S7. 13C-NMR spectrum of Complex 2 CDCl3 at 25ºC.
S8

Figure S8. 1H-NMR spectrum of Complex 3 DMSO-d6 at 25ºC.
S9

Figure S9. 13C-NMR spectrum of Complex 3 DMSO-d6 at 25ºC.
S10

Figure S10. 1H-NMR spectrum of Complex 4 DMSO-d6 at 25ºC.
S11

Figure S11. 13C-NMR spectrum of Complex 4 DMSO-d6 at 25ºC.
S12

Figure S12. 19F-NMR spectra of TBA-F in DMSO-d6 at 25ºC. Hexafluorobenzene was used as standard.
S13

Figure S13. 19F-NMR spectra of mixture of TBA-F and L1 in DMSO-d6 at 25ºC. Hexafluorobenzene was used as standard.
S14