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Ihm H, Ahn JS, Lah MS, Ko YH, Paek K. Oligobisvelcraplex: Self-Assembled Linear Oligomer by Solvophobic π−π Stacking Interaction of Bisvelcrands Based on Resorcin[4]arene. Org Lett 2004; 6:3893-6. [PMID: 15496057 DOI: 10.1021/ol048539f] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] Bisvelcrand 3 based on resorcin[4]arene was obtained by a stepwise route, and the formation of oligobisvelcraplex 3(n) by solvophobic pi-pistacking interaction was observed. (1)H NMR spectroscopic studies revealed that DeltaG(++)(pseudorotation) of oligobisvelcraplex 3(n) is 16.7 kcal mol(-1) in C(6)D(5)NO(2) solution. The pulsed field gradient spin-echo (PGSE) NMR experiment and VPO experiment showed that the number of aggregation (n) ranges from 7 to 10 in CHCl(3) solution at 298 K. In high concentration, bisvelcrand 3 tends to form gels or fiber.
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Affiliation(s)
- Hyejae Ihm
- CAMDRC and Department of Chemistry, Soongsil University, Seoul 156-743, Korea
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Yun S, Ihm H, Kim HG, Lee CW, Indrajit B, Oh KS, Gong YJ, Lee JW, Yoon J, Lee HC, Kim KS. Molecular recognition of fluoride anion: benzene-based tripodal imidazolium receptor. J Org Chem 2003; 68:2467-70. [PMID: 12636418 DOI: 10.1021/jo0263519] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A benzene-based tripodal imidazolium receptor utilizing the strong (C-H)(+)...X(-) hydrogen bonding interaction between imidazolium moieties and halide anions is extensively investigated both theoretically and experimentally. Ab initio calculations predict that this receptor has a very high affinity for fluoride ion (F(-)). The association constant and free energy gain of the N-butyl receptor 2 for F(-) in acetonitrile were measured to be 2.1 x 10(5) M(-1) and -7.25 kcal/mol, respectively, showing that the receptor has a high affinity for F(-) in highly polar organic solvents.
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Affiliation(s)
- Sunggoo Yun
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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Kim HG, Lee CW, Yun S, Hong BH, Kim YO, Kim D, Ihm H, Lee JW, Lee EC, Tarakeshwar P, Park SM, Kim KS. An Electrochemically Controllable Nanomechanical Molecular System Utilizing Edge-to-Face and Face-to-Face Aromatic Interactions. Org Lett 2003. [DOI: 10.1021/ol034183g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Yun S, Kim YO, Kim D, Kim HG, Ihm H, Kim JK, Lee CW, Lee WJ, Yoon J, Oh KS, Yoon J, Park SM, Kim KS. Rational design of biologically important chemosensors: a novel receptor for selective recognition of acetylcholine over ammonium cations. Org Lett 2003; 5:471-4. [PMID: 12583746 DOI: 10.1021/ol0273203] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[structure: see text] In consideration of competition between cation-pi and hydrogen bond interaction forces, we designed a novel receptor, 1,3,5-tris(pyrrolyl)benzene, which shows high selectivity for acetylcholine (ACh). The selectivity of the receptor for ACh over other ammonium cations is demonstrated by the ion-selective electrode (ISE) method in buffer solution. The binding free energy of the receptor with ACh in chloroform solution is measured to be 3.65 kcal/mol in the presence of chloride anion by nuclear magnetic resonance spectroscopy, and that in water is estimated to be much greater ( approximately 6 kcal/mol).
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Affiliation(s)
- Sunggoo Yun
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology San 31, Hyojadong, Namgu, Pohang, 790-784, Korea
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Kim KS, Suh SB, Kim JC, Hong BH, Lee EC, Yun S, Tarakeshwar P, Lee JY, Kim Y, Ihm H, Kim HG, Lee JW, Kim JK, Lee HM, Kim D, Cui C, Youn SJ, Chung HY, Choi HS, Lee CW, Cho SJ, Jeong S, Cho JH. Assembling phenomena of calix[4]hydroquinone nanotube bundles by one-dimensional short hydrogen bonding and displaced pi-pi stacking. J Am Chem Soc 2002; 124:14268-79. [PMID: 12440926 DOI: 10.1021/ja0259786] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Using the computer-aided molecular design approach, we recently reported the synthesis of calix[4]hydroquinone (CHQ) nanotube arrays self-assembled with infinitely long one-dimensional (1-D) short hydrogen bonds (H-bonds) and aromatic-aromatic interactions. Here, we assess various calculation methods employed for both the design of the CHQ nanotubes and the study of their assembly process. Our calculations include ab initio and density functional theories and first principles calculations using ultrasoft pseudopotential plane wave methods. The assembly phenomena predicted prior to the synthesis of the nanotubes and details of the refined structure and electronic properties obtained after the experimental characterization of the nanotube crystal are reported. For better characterization of intriguing 1-D short H-bonds and exemplary displaced pi-pi stacks, the X-ray structures have been further refined with samples grown in different solvent conditions. Since X-ray structures do not contain the positions of H atoms, it is necessary to analyze the system using quantum theoretical calculations. The competition between H-bonding and displaced pi-pi stacking in the assembling process has been clarified. The IR spectroscopic features and NMR chemical shifts of 1-D short H-bonds have been investigated both experimentally and theoretically. The dissection of the two most important interaction components leading to self-assembly processes would help design new functional materials and nanomaterials.
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Affiliation(s)
- Kwang S Kim
- National Creative Research Initiative Center for Superfunctional Materials and Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea.
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Kim HG, Lee CW, Yun S, Hong BH, Kim YO, Kim D, Ihm H, Lee JW, Lee EC, Tarakeshwar P, Park SM, Kim KS. An electrochemically controllable nanomechanical molecular system utilizing edge-to-face and face-to-face aromatic interactions. Org Lett 2002; 4:3971-4. [PMID: 12599505 DOI: 10.1021/ol0268541] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
[formula: see text] A new molecular system, 2,11-dithio[4,4]metametaquinocyclophane containing a quinone moiety, was designed and synthesized. As the quinone moiety can readily be converted into an aromatic pi-system (hydroquinone) upon reduction, the nanomechanical molecular cyclophane system exhibits a large flapping motion like a molecular flipper from the electrochemical redox process. The conformational changes upon reduction and oxidation are caused by changes of nonbonding interaction forces (devoid of bond formation/breaking) from the edge-to-face to face-to-face aromatic interactions and vice versa, respectively.
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Affiliation(s)
- Heon Gon Kim
- National Creative Research Initiative 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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Abstract
[structure: see text] A positively charged tripodal receptor with nitro groups in the imidazolium rings was designed, synthesized, and characterized for its anion binding strength. The receptor shows strong affinity and high selectivity for Cl- through (C-H)+- - -X(-) hydrogen bonds wherein charge-charge and charge-dipole electrostatic interactions dominate. The association constant with chloride anion in a 9:1 mixture of acetonitrile-d3 and DMSO-d6 is measured to be 1.1 x 10(6) M(-1). The receptor also shows reasonably high affinity toward H2PO4-.
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Affiliation(s)
- Hyejae Ihm
- National Creative Research Initiative Center for Superfunctional Materials, Department of Chemistry, Division of Molecular and Life Sciences, Pohang University of Science and Technology, San 31, Hyojadong, Namgu, Pohang 790-784, Korea
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Paek K, Ihm H, Yun S, Lee HC, No KT. Molecular engineering. 8. Kinetic and conformational studies of resorcin [4]arene-based C4 tetraoxatetrathiahemicarceplexes: carceroisomerism and twistomerism. J Org Chem 2001; 66:5736-43. [PMID: 11511247 DOI: 10.1021/jo015594i] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New C(4v) tetraoxatetrathiahemicarcerands and their six hemicarceplexes containing DMF, DMA, DMSO, or NMP were synthesized and characterized. Their conformations, kinetic properties, carceroisomerism, and twistomerism were studied by VT, 2D COSY, NOESY, and ROESY (1)H NMR experiments. The decomplexation rates of DMF or DMA were very slow with high activation energy barriers (73 and 104 kJ mol(-1), respectively) and the complexed guests feel more constriction than their free liquid state. The largest isomerization energy barrier of carceroisomers was 15.4 kcal mol(-1), and the isomerization energy barriers of twistomers are significantly larger than those of carceroisomers.
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Affiliation(s)
- K Paek
- Molecular Engineering Research Laboratory and Department of Chemistry, Soongsil University, Seoul 156-743, Korea.
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Affiliation(s)
- H. Ihm
- Center for Materials Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - J. M. White
- Center for Materials Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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Affiliation(s)
- T. B. Scoggins
- Center for Materials Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - H. Ihm
- Center for Materials Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - Y. M. Sun
- Center for Materials Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
| | - J. M. White
- Center for Materials Chemistry, Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712
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Affiliation(s)
- D. Sloan
- Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712
| | - Y.-M. Sun
- Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712
| | - H. Ihm
- Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712
| | - J. M. White
- Department of Chemistry and Biochemistry, University of Texas, Austin, Texas 78712
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Ihm H, Kim H, Paek K. Molecular engineering. Part 2.1 Influence of side-chain substituents in lariat-type upper-rim calix[4]crowns on their binding properties and the reversal of these. ACTA ACUST UNITED AC 1997. [DOI: 10.1039/a700165g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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