2201
|
|
2202
|
Vermonden T, van der Gucht J, de Waard P, Marcelis ATM, Besseling NAM, Sudhölter EJR, Fleer GJ, Cohen Stuart MA. Water-Soluble Reversible Coordination Polymers: Chains and Rings. Macromolecules 2003. [DOI: 10.1021/ma030353t] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tina Vermonden
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Jasper van der Gucht
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Pieter de Waard
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Antonius T. M. Marcelis
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Nicolaas A. M. Besseling
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Ernst J. R. Sudhölter
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Gerard J. Fleer
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - Martien A. Cohen Stuart
- Dutch Polymer Institute/Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, and Wageningen NMR Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| |
Collapse
|
2203
|
Zhang ZB, Motonaga M, Fujiki M, McKenna CE. The First Optically Active Polycarbazoles. Macromolecules 2003. [DOI: 10.1021/ma0344184] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Zhong-Biao Zhang
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744; JST-CREST; and Advanced Polymer Science Laboratory, Graduate School of Material Science, Nara Advanced Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| | - Masao Motonaga
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744; JST-CREST; and Advanced Polymer Science Laboratory, Graduate School of Material Science, Nara Advanced Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| | - Michiya Fujiki
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744; JST-CREST; and Advanced Polymer Science Laboratory, Graduate School of Material Science, Nara Advanced Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| | - Charles E. McKenna
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-0744; JST-CREST; and Advanced Polymer Science Laboratory, Graduate School of Material Science, Nara Advanced Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
| |
Collapse
|
2204
|
You CC, Würthner F. Self-assembly of ferrocene-functionalized perylene bisimide bridging ligands with PtII corner to electrochemically active molecular squares. J Am Chem Soc 2003; 125:9716-25. [PMID: 12904037 DOI: 10.1021/ja029648x] [Citation(s) in RCA: 140] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ferrocenyl-substituted N,N'-di(4-pyridyl)perylene bisimide ligands have been synthesized by the coupling reaction of hydroxyphenoxy-perylene bisimides with ferrocenyl carboxylic acids. By means of metallosupramolecular self-assembly, hitherto unprecedented multiredox active dendritic molecular squares with 16 ferrocene groups positioned in the bridging ligands are prepared from the perylene bispyridyl imide ligands and [Pt(dppp)][(OTf)(2)] (dppp = 1,3-bis(diphenylphosphano)propane; OTf = trifluoromethanesulfonate) corner in high yield. The isolated metallosupramolecular squares were characterized by elemental analysis, (1)H, (31)P[(1)H] NMR, and UV/vis spectroscopy. The electrochemical properties of the ligands and squares are investigated by cyclic voltammetry as well as spectroelectrochemistry. The results obtained show that the redox behavior of ferrocene units is influenced by the square superstructure. Furthermore, redox titration of free ligand and corresponding molecular square with the one-electron oxidant thianthrenium pentachloroantimonate reveals that ferrocene groups in these structures may be oxidized completely by this oxidant, and highly charged species generated through oxidation of ferrocenyl groups in molecular square cause decomposition of the assembly due to pronounced Coulombic repulsion.
Collapse
Affiliation(s)
- Chang-Cheng You
- Institut für Organische Chemie, Universität Würzburg, Am Hubland, Germany
| | | |
Collapse
|
2205
|
Li G, Hou H, Li L, Meng X, Fan Y, Zhu Y. Novel Pb(II), Zn(II), and Cd(II) coordination polymers constructed from ferrocenyl-substituted carboxylate and bipyridine-based ligands. Inorg Chem 2003; 42:4995-5004. [PMID: 12895125 DOI: 10.1021/ic034324a] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Treatment of two kinds of ferrocenyl-substituted carboxylate ligands (3-ferrocenyl-2-crotonic acid, HOOC-CH=(CH(3))CFc (Fc=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4))) or O-ferrocecarbonyl benzoic acid, o-HOOCC(6)H(4)COFc with Pb(OAc)(2).3H(2)O, Zn(OAc)(2).2H(2)O, or Cd(OAc)(2).2H(2)O) resulted in four novel ferrocene-containing coordination polymers [[Pb(mu(2)-eta(2)-OOCCH=(CH(3))CFc)(2)].MeOH](n) (1), [[Zn(o-OOCC(6)H(4)COFc)(2)(4,4'-bipy)(H(2)O)(2)].2MeOH.2H(2)O](n) (4,4'-bipy = 4,4'-bipyridine) (2), [[Cd(o-OOCC(6)H(4)COFc)(2)(bpe)(MeOH)(2)].2H(2)O](n) (bpe = 1,2-bis(4-pyridyl)ethene) (3), and [Pb(o-OOCC(6)H(4)COFc)(eta(2)-o-OOCC(6)H(4)COFc)(bpe)](n)() (4). Their crystal structures have been characterized by single X-ray determinations. In polymer 1, Pb(II) ions are bridged by tridentate FcC(CH(3))=CHCOO(-) anions, forming an infinite chain [Pb(mu(2)-eta(2)-OOC=CH(CH(3))CFc)(2)](n). In polymers 2-4, there are three kinds of components, metal ions, o-FcCOC(6)H(4)COO(-) units, and organic bridging ligands. The bipyridine-based ligands connect metal ions leading to a one-dimensional chain with o-FcCOC(6)H(4)COO(-) units acting as monodentate or chelate ligands in the side chain. Such coordination polymers containing ferrocenyl-substituted carboxylate and bipyridine-based ligands are very rare. The solution-state differential pulse voltammetries of polymers 1-4 were determined. The results indicate that the half-wave potential of the ferrocenyl moieties is influenced by the Pb(II) ions in polymer 1 and strongly influenced by Zn(II), Cd(II), or Pb(II) ions in polymers 2-4. The thermal properties of the four polymers were also investigated.
Collapse
Affiliation(s)
- Gang Li
- Department of Chemistry, Zhengzhou University, Henan 450052, P. R. China
| | | | | | | | | | | |
Collapse
|
2206
|
Zeng-guo F, Sanping Z. Synthesis and characterization of biodegradable hydrogels based on photopolymerizable acrylate-terminated CL-PEG-CL macromers with supramolecular assemblies of α-cyclodextrins. POLYMER 2003. [DOI: 10.1016/s0032-3861(03)00505-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
2207
|
Carroll JB, Waddon AJ, Nakade H, Rotello VM. “Plug and Play” Polymers. Thermal and X-ray Characterizations of Noncovalently Grafted Polyhedral Oligomeric Silsesquioxane (POSS)−Polystyrene Nanocomposites. Macromolecules 2003. [DOI: 10.1021/ma034652u] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph B. Carroll
- Department of Chemistry and Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003
| | - Alan J. Waddon
- Department of Chemistry and Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003
| | - Hiroshi Nakade
- Department of Chemistry and Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003
| | - Vincent M. Rotello
- Department of Chemistry and Department of Polymer Science and Engineering, University of Massachusetts, Amherst, Massachusetts 01003
| |
Collapse
|
2208
|
Nonokawa R, Oobo M, Yashima E. Helicity Induction on a Poly(phenylacetylene) Derivative Bearing Aza-15-crown-5 Ether Pendants in Organic Solvents and Water. Macromolecules 2003. [DOI: 10.1021/ma034547k] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ryuji Nonokawa
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
| | - Masato Oobo
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
| | - Eiji Yashima
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
| |
Collapse
|
2209
|
Inai Y, Ousaka N, Okabe T. Mechanism for the noncovalent chiral domino effect: new paradigm for the chiral role of the N-terminal segment in a 3(10)-helix. J Am Chem Soc 2003; 125:8151-62. [PMID: 12837085 DOI: 10.1021/ja035040s] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, novel chiral interactions on 3(10)-helical peptides, of which the helicity is controlled by external chiral stimulus operating on the N-terminus, were proposed as a "noncovalent chiral domino effect (NCDE)" (Inai, Y.; et al. J. Am. Chem. Soc. 2000, 122, 11731. Inai, Y.; et al. J. Am. Chem. Soc. 2002, 124, 2466). The present study clarifies the mechanism for generating the NCDE. For this purpose, achiral nonapeptide (1), H-beta-Ala-(Delta(Z)Phe-Aib)(4)-OMe [Delta(Z)Phe = (Z)-didehydrophenylalanine, Aib = alpha-aminoisobutyric acid], was synthesized. Peptide 1 alone adopts a 3(10)-helical conformation in chloroform. On the basis of the induced CD signals of peptide 1 with chiral additives, chiral acid enabling the predominant formation of a one-handed helix was shown to need at least both carboxyl and urethane groups; that is, Boc-l-amino acid (Boc = tert-butoxycarbonyl) strongly induces a right-handed helix. NMR studies (NH resonance variations, low-temperature measurement, and NOESY) were performed for a CDCl(3) solution of peptide 1 and chiral additive, supporting the view that the N-terminal H-beta-Ala-Delta(Z)Phe-Aib, including the two free amide NH's, captures effectively a Boc-amino acid molecule through three-point interactions. The H-beta-Ala's amino group binds to the carboxyl group to form a salt bridge, while the Aib(3) NH is hydrogen-bonded to either oxygen of the carboxylate group. Subsequently, the free Delta(Z)Phe(2) NH forms a hydrogen bond to the urethane carbonyl oxygen. A semiempirical molecular orbital computation explicitly demonstrated that the dynamic looping complexation is energetically permitted and that the N-terminal segment of a right-handed 3(10)-helix binds more favorably to a Boc-l-amino acid than to the corresponding d-species. In conclusion, the N-terminal segment of a 3(10)-helix, ubiquitous in natural proteins and peptides, possesses the potency of chiral recognition in the backbone itself, furthermore enabling the conversion of the terminally acquired chiral sign and power into a dynamic control of the original helicity and helical stability.
Collapse
Affiliation(s)
- Yoshihito Inai
- Department of Environmental Technology and Urban Planning, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
| | | | | |
Collapse
|
2210
|
Keizer HM, Sijbesma RP, Jansen JFGA, Pasternack G, Meijer EW. Polymerization-Induced Phase Separation Using Hydrogen-Bonded Supramolecular Polymers. Macromolecules 2003. [DOI: 10.1021/ma034284u] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Henk M. Keizer
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5300 MB, Eindhoven; DSM Research, Section RP-CT, P.O. Box 18, 6160 MD, Geleen, The Netherlands; and DSM Desotech Inc., 1122 St. Charles Street, Elgin, Illinois 60120
| | - Rint P. Sijbesma
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5300 MB, Eindhoven; DSM Research, Section RP-CT, P.O. Box 18, 6160 MD, Geleen, The Netherlands; and DSM Desotech Inc., 1122 St. Charles Street, Elgin, Illinois 60120
| | - Johan F. G. A. Jansen
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5300 MB, Eindhoven; DSM Research, Section RP-CT, P.O. Box 18, 6160 MD, Geleen, The Netherlands; and DSM Desotech Inc., 1122 St. Charles Street, Elgin, Illinois 60120
| | - George Pasternack
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5300 MB, Eindhoven; DSM Research, Section RP-CT, P.O. Box 18, 6160 MD, Geleen, The Netherlands; and DSM Desotech Inc., 1122 St. Charles Street, Elgin, Illinois 60120
| | - E. W. Meijer
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5300 MB, Eindhoven; DSM Research, Section RP-CT, P.O. Box 18, 6160 MD, Geleen, The Netherlands; and DSM Desotech Inc., 1122 St. Charles Street, Elgin, Illinois 60120
| |
Collapse
|
2211
|
Kjøniksen AL, Hiorth M, Roots J, Nyström B. Shear-Induced Association and Gelation of Aqueous Solutions of Pectin. J Phys Chem B 2003. [DOI: 10.1021/jp0302358] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Anna-Lena Kjøniksen
- Department of Chemistry, University of Oslo, Post Office Box 1033, Blindern, N-0315 Oslo, Norway, and Department of Pharmaceutics, School of Pharmacy, University of Oslo, Post Office Box 1068, Blindern, N-0316 Oslo, Norway
| | - Marianne Hiorth
- Department of Chemistry, University of Oslo, Post Office Box 1033, Blindern, N-0315 Oslo, Norway, and Department of Pharmaceutics, School of Pharmacy, University of Oslo, Post Office Box 1068, Blindern, N-0316 Oslo, Norway
| | - Jaan Roots
- Department of Chemistry, University of Oslo, Post Office Box 1033, Blindern, N-0315 Oslo, Norway, and Department of Pharmaceutics, School of Pharmacy, University of Oslo, Post Office Box 1068, Blindern, N-0316 Oslo, Norway
| | - Bo Nyström
- Department of Chemistry, University of Oslo, Post Office Box 1033, Blindern, N-0315 Oslo, Norway, and Department of Pharmaceutics, School of Pharmacy, University of Oslo, Post Office Box 1068, Blindern, N-0316 Oslo, Norway
| |
Collapse
|
2212
|
Hoogenboom R, Wouters D, Schubert US. l-Lactide Polymerization Utilizing a Hydroxy-Functionalized 3,6-Bis(2-pyridyl)pyridazine as Supramolecular (Co)initiator: Construction of Polymeric [2 × 2] Grids. Macromolecules 2003. [DOI: 10.1021/ma034119e] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Richard Hoogenboom
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute (DPI), PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Daan Wouters
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute (DPI), PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Ulrich S. Schubert
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute (DPI), PO Box 513, 5600 MB Eindhoven, The Netherlands
| |
Collapse
|
2213
|
|
2214
|
Li JR, Du M, Bu XH, Zhang RH. Extended chains via hydrogen bond linkages of dinuclear copper(II) and cadmium(II) complexes with a new flexible disulfoxide ligand. J SOLID STATE CHEM 2003. [DOI: 10.1016/s0022-4596(03)00055-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
2215
|
Aoki T, Kaneko T, Maruyama N, Sumi A, Takahashi M, Sato T, Teraguchi M. Helix-sense-selective polymerization of phenylacetylene having two hydroxy groups using a chiral catalytic system. J Am Chem Soc 2003; 125:6346-7. [PMID: 12785756 DOI: 10.1021/ja021233o] [Citation(s) in RCA: 291] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have found a simple and novel synthetic method for obtaining a chiral polymer from an achiral monomer by using a chiral catalytic system. The chirality of the polymer was caused only by a one-handed helical backbone, and the polymer had no other chiral structures in the side groups. In addition, the helical conformation was stable in solution by itself. This is the first example of helix-sense-selective polymerization of a substituted acetylene. The stability of the helicity was found to be caused by intramolecular hydrogen bonds.
Collapse
Affiliation(s)
- Toshiki Aoki
- Department of Chemistry and Chemical Engineering, Faculty of Engineering, Niigata University, Ikarashi 2-8050, Niigata 950-2181, Japan.
| | | | | | | | | | | | | |
Collapse
|
2216
|
Goward GR, Sebastiani D, Schnell I, Spiess HW, Kim HD, Ishida H. Benzoxazine oligomers: evidence for a helical structure from solid-state NMR spectroscopy and DFT-based dynamics and chemical shift calculations. J Am Chem Soc 2003; 125:5792-800. [PMID: 12733920 DOI: 10.1021/ja029059r] [Citation(s) in RCA: 108] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A combination of molecular modeling, DFT calculations, and advanced solid-state NMR experiments is used to elucidate the supramolecular structure of a series of benzoxazine oligomers. Intramolecular hydrogen bonds are characterized and identified as the driving forces for ring-shape and helical conformations of trimeric and tetrameric units. In fast MAS (1)H NMR spectra, the resonances of the protons forming the hydrogen bonds can be assigned and used for validating and refining the structure by means of DFT-based geometry optimizations and (1)H chemical-shift calculations. Also supporting these proposed structures are homonuclear (1)H[bond](1)H double-quantum NMR spectra, which identify the local proton-proton proximities in each material. Additionally, quantitative (15)N[bond](1)H distance measurements obtained by analysis of dipolar spinning sideband patterns confirm the optimized geometry of the tetramer. These results clearly support the predicted helical geometry of the benzoxazine polymer. This geometry, in which the N...H...O and O...H...O hydrogen bonds are protected on the inside of the helix, can account for many of the exemplary chemical properties of the polybenzoxazine materials. The combination of advanced experimental solid-state NMR spectroscopy with computational geometry optimizations, total energy, and NMR spectra calculations is a powerful tool for structural analysis. Its results provide significantly more confidence than the individual measurements or calculations alone, in particular, because the microscopic structure of many disordered systems cannot be elucidated by means of conventional methods due to lack of long-range order.
Collapse
Affiliation(s)
- Gillian R Goward
- Max-Planck-Institut für Polymerforschung, Postfach 3148, D-55021 Mainz, Germany
| | | | | | | | | | | |
Collapse
|
2217
|
Parrish DA, Mathias LJ, Moore KM. Supramolecular Materials from Multifunctional Pyroglutamic Acid Derivatives. Macromolecules 2003. [DOI: 10.1021/ma034426k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dennis A. Parrish
- School of Polymers and High Performance Materials, The University of Southern Mississippi, Box 10076 Hattiesburg, Mississippi 39406-0076
| | - Lon J. Mathias
- School of Polymers and High Performance Materials, The University of Southern Mississippi, Box 10076 Hattiesburg, Mississippi 39406-0076
| | - Kate M. Moore
- School of Polymers and High Performance Materials, The University of Southern Mississippi, Box 10076 Hattiesburg, Mississippi 39406-0076
| |
Collapse
|
2218
|
El-ghayoury A, Hofmeier H, de Ruiter B, Schubert US. Combining Covalent and Noncovalent Cross-Linking: A Novel Terpolymer for Two-Step Curing Applications. Macromolecules 2003. [DOI: 10.1021/ma026011p] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Abdelkrim El-ghayoury
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Functional Polymers and Coatings, TNO Industrial Technology, De Rondom 1, P.O. Box 6235, 5600 HE Eindhoven, The Netherlands
| | - Harald Hofmeier
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Functional Polymers and Coatings, TNO Industrial Technology, De Rondom 1, P.O. Box 6235, 5600 HE Eindhoven, The Netherlands
| | - Barteld de Ruiter
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Functional Polymers and Coatings, TNO Industrial Technology, De Rondom 1, P.O. Box 6235, 5600 HE Eindhoven, The Netherlands
| | - Ulrich S. Schubert
- Laboratory of Macromolecular Chemistry and Nanoscience, Eindhoven University of Technology and Dutch Polymer Institute, P.O. Box 513, 5600 MB Eindhoven, The Netherlands, and Functional Polymers and Coatings, TNO Industrial Technology, De Rondom 1, P.O. Box 6235, 5600 HE Eindhoven, The Netherlands
| |
Collapse
|
2219
|
Syntheses and X-ray crystal structures of poly(pyridylsulfanylmethyl)arenes: new multi-armed molecules. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00550-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
2220
|
van der Gucht J, Besseling NAM, Knoben W, Bouteiller L, Cohen Stuart MA. Brownian particles in supramolecular polymer solutions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 67:051106. [PMID: 12786133 DOI: 10.1103/physreve.67.051106] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2003] [Indexed: 05/23/2023]
Abstract
The Brownian motion of colloidal particles embedded in solutions of hydrogen-bonded supramolecular polymers has been studied using dynamic light scattering. At short times, the motion of the probe particles is diffusive with a diffusion coefficient equal to that in pure solvent. At intermediate time scales the particles are slowed down as a result of trapping in elastic cages formed by the polymer chains, while at longer times the motion is diffusive again, but with a much smaller diffusion coefficient. The influence of particle size and polymer concentration was investigated. The experimental data are compared to a theoretical expression for the mean-square displacement of an embedded particle in a viscoelastic medium, in which the solvent is explicitly taken into account. Differences between the friction and elastic forces experienced by the particle and the macroscopic viscosity and elasticity are explained by the inhomogeneity of the medium on the length scale of the particle size.
Collapse
Affiliation(s)
- J van der Gucht
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, P.O. Box 8038, 6700 EK Wageningen, The Netherlands.
| | | | | | | | | |
Collapse
|
2221
|
Takasawa R, Murota K, Yoshikawa I, Araki K. Steric-Factor-Directed Alternating Supramolecular Copolymer Composed of Hydrogen-Bonded Cyclohexanetricarboxamide Units. Macromol Rapid Commun 2003. [DOI: 10.1002/marc.200390052] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
2222
|
Jones JW, Bryant WS, Bosman AW, Janssen RAJ, Meijer EW, Gibson HW. Crowned dendrimers: pH-responsive pseudorotaxane formation. J Org Chem 2003; 68:2385-9. [PMID: 12636406 DOI: 10.1021/jo0265784] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
With the end goal of incorporating the unique structural and physical properties of dendrimers into supramolecular assemblies, bis(m-phenylene)-32-crown-10-functionalized poly(propyleneimine) dendrimers of the first and third generations have been synthesized and their interaction with paraquat diol has been investigated. Using (1)H NMR, we determined that binding to the 4 or 16 crown ether sites occurred in an anti-cooperative fashion, most likely a result of steric influences. Upon protonation of the tertiary amines in the dendritic interior, binding became independent, i.e., statistical, and the average apparent association constant increased by nearly 5-fold; this effect is attributed to rigidification of the dendrimer, which makes its binding sites more accessible and less crowded.
Collapse
Affiliation(s)
- Jason W Jones
- Department of Chemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212, USA
| | | | | | | | | | | |
Collapse
|
2223
|
Nonokawa R, Yashima E. Detection and amplification of a small enantiomeric imbalance in alpha-amino acids by a helical poly(phenylacetylene) with crown ether pendants. J Am Chem Soc 2003; 125:1278-83. [PMID: 12553829 DOI: 10.1021/ja028348c] [Citation(s) in RCA: 181] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have designed a novel stereoregular poly(phenylacetylene) bearing the bulky crown ether as the pendant (poly-1) for the amino acid binding site. The polymer forms a one-handed helix upon complexation with l-amino acid perchlorates, and the complexes exhibit an induced circular dichroism (ICD) with the same Cotton effect signs in the polymer backbone region through a significant cooperative interaction. Poly-1 is highly sensitive to the amino acid chirality and can detect an extremely small enantiomeric imbalance in alpha-amino acids (less than 0.005% enantiomeric excess of alanine, for example).
Collapse
Affiliation(s)
- Ryuji Nonokawa
- Department of Molecular Design and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-ku, Nagoya 464-8603, Japan
| | | |
Collapse
|
2224
|
Yamauchi K, Lizotte JR, Long TE. Thermoreversible Poly(alkyl acrylates) Consisting of Self-Complementary Multiple Hydrogen Bonding. Macromolecules 2003. [DOI: 10.1021/ma0212801] [Citation(s) in RCA: 211] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Koji Yamauchi
- Department of Chemistry, Polymeric Materials and Interfaces Laboratories and the Center for Adhesive and Sealant Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212
| | - Jeremy R. Lizotte
- Department of Chemistry, Polymeric Materials and Interfaces Laboratories and the Center for Adhesive and Sealant Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212
| | - Timothy E. Long
- Department of Chemistry, Polymeric Materials and Interfaces Laboratories and the Center for Adhesive and Sealant Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212
| |
Collapse
|
2225
|
Inai Y, Komori H, Takasu A, Hirabayashi T. Noncovalent chiral domino effect on one-handed helix of nonapeptide containing a midpoint L-residue. Biomacromolecules 2003; 4:122-8. [PMID: 12523856 DOI: 10.1021/bm0256303] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We here clarify whether noncovalent chiral domino effect characterized by the terminal interaction of a helical peptide with a chiral small molecule can alter the helical stability of N-deprotected peptides containing an L-residue covalently incorporated into the inner position. Two nonapeptides consisting of the midpoint L-leucine (1) or L-phenylalanine (2) and the achiral helix-forming residues were employed. NMR and IR spectroscopy and energy calculation indicated that both peptides adopt a 3(10)-helical conformation in chloroform. They strongly preferred a right-handed screw sense because of the presence of the midpoint L-residue. These original right-handed screw senses were retained on addition of chiral Boc-amino acid, but their helical stabilities clearly depended on its added chirality. Here, Boc-L-amino acid stabilizes the original right-handed helix, whereas the corresponding Boc-D-amino acid tends to less stabilize or destabilize it. This tendency was not observed for the corresponding N-Boc-protected peptides 1 and 2, strongly suggesting that the N-terminal amino group is required for controlling the stabilization of the original right-handed helix. Therefore, noncovalent chiral domino effect in peptides 1 and 2 can contribute even to the helical stability of a chiral peptide prevailing one-handed helix strongly through the midpoint L-residue. In addition, the N-terminal moiety of a 3(10)-helical peptide was found to generate chiral discrimination in complexation process with racemic additives.
Collapse
Affiliation(s)
- Yoshihito Inai
- Department of Environmental Technology and Urban Planning, Graduate School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
| | | | | | | |
Collapse
|
2226
|
Ding S, Yang J, Radosz M, Shen Y. Atom transfer radical polymerization of methyl methacrylate via reversibly supported catalysts on silica gel via self-assembly. ACTA ACUST UNITED AC 2003. [DOI: 10.1002/pola.10978] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
2227
|
Banerjee A, Maji SK, Drew MG, Haldar D, Banerjee A. Supramolecular peptide helix from a novel double turn forming peptide containing a β-amino acid. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(02)02675-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
2228
|
Sivakova S, Rowan SJ. Fluorescent supramolecular liquid crystalline polymers from nucleobase-terminated monomers. Chem Commun (Camb) 2003:2428-9. [PMID: 14587715 DOI: 10.1039/b307877a] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
While thymine or N6-(4-methoxybenzoyl)adenine terminated bis(4-alkoxy)-substituted bis(phenylethynyl)benzene monomers show no liquid crystalline behaviour by themselves, mixing the complementary nucleobase monomers together results in the formation of thermotropic liquid crystalline phases.
Collapse
Affiliation(s)
- Sona Sivakova
- Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Road, Cleveland, Ohio, USA
| | | |
Collapse
|
2229
|
Wang LY, Igarashi S, Yukawa Y, Hoshino Y, Roubeau O, Aromí G, Winpenny REP. Synthesis, structure, and preliminary magnetic studies of unprecedented hexacopper(ii) barrel clusters with spin ground state S = 3. Dalton Trans 2003. [DOI: 10.1039/b212494g] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
2230
|
Öjelund K, Loontjens T, Steeman P, Palmans A, Maurer F. Synthesis, Structure and Properties of Melamine-Based pTHF-Urethane Supramolecular Compounds. MACROMOL CHEM PHYS 2003. [DOI: 10.1002/macp.200290055] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
2231
|
Otsuka H, Aotani K, Higaki Y, Takahara A. A dynamic (reversible) covalent polymer: radical crossover behaviour of TEMPO-containing poly(alkoxyamine ester)s. Chem Commun (Camb) 2002:2838-9. [PMID: 12478772 DOI: 10.1039/b209193c] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A dynamic covalent polymer incorporating thermally alkoxyamine units in the main chain was synthesized. Due to a radical crossover reaction between the alkoxyamine units, an interchange of the main chains in poly(alkoxyamine ester) was observed on heating.
Collapse
Affiliation(s)
- Hideyuki Otsuka
- Institute for Fundamental Research of Organic Chemistry, Kyushu University, Hakozaki, Higashi-ku, Fukuoka 812-858, Japan.
| | | | | | | |
Collapse
|
2232
|
Beckers EHA, Schenning APHJ, van Hal PA, el-ghayoury A, Sánchez L, Hummelen JC, Meijer EW, Janssen RAJ. Preferential hetero-dimer formation and equilibrium dynamics of self-complementary bifunctional oligo(p-phenylenevinylene) and C60 ureido-pyrimidinone derivatives in solution. Chem Commun (Camb) 2002:2888-9. [PMID: 12478797 DOI: 10.1039/b208074e] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The formation of hetero-dimers of bifunctional oligo(p-phenylenevinylene) and C60 ureido-pyrimidinone derivatives has been observed by 1H-NMR and fluorescence techniques.
Collapse
Affiliation(s)
- Edwin H A Beckers
- Laboratory of Macromolecular and Organic Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
2233
|
Ishida Y, Aida T. Homochiral supramolecular polymerization of an "S"-shaped chiral monomer: translation of optical purity into molecular weight distribution. J Am Chem Soc 2002; 124:14017-9. [PMID: 12440899 DOI: 10.1021/ja028403h] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An "S"-shaped chiral motif of a p-xylylene-bridged bis(cyclic dipeptide) (1), having four hydrogen-bonding amide functionalities, formed a homochiral supramolecular polymer in solution. X-ray crystallography of a slightly modified version of 1 for an enhanced crystallinity showed one-dimensional columnar assemblies via four double hydrogen-bonding interactions. Model studies with half-protected analogues of 1 indicated a nearly perfect enantioselectivity in hydrogen-bonding dimerization. When 1 was not racemic but enriched in either of the enantiomers, a supramolecular polymer with a bimodal molecular weight distribution resulted, due to the formation of two homochiral polymers with different molecular weights. By taking advantage of this, separation of optically pure 1 from an enantiomerically unbalanced mixture was possible by means of size-exclusion chromatography.
Collapse
Affiliation(s)
- Yasuhiro Ishida
- Department of Chemistry and Biotechnology, Graduate School of Engineering,The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | | |
Collapse
|
2234
|
Yamauchi K, Lizotte JR, Long TE. Synthesis and Characterization of Novel Complementary Multiple-Hydrogen Bonded (CMHB) Macromolecules via a Michael Addition. Macromolecules 2002. [DOI: 10.1021/ma020961t] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Koji Yamauchi
- Department of Chemistry, Polymeric Materials and Interfaces Laboratories and the Center for Adhesive and Sealant Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212
| | - Jeremy R. Lizotte
- Department of Chemistry, Polymeric Materials and Interfaces Laboratories and the Center for Adhesive and Sealant Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212
| | - Timothy E. Long
- Department of Chemistry, Polymeric Materials and Interfaces Laboratories and the Center for Adhesive and Sealant Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212
| |
Collapse
|
2235
|
El-Ghayoury A, Schenning APHJ, Meijer EW. Synthesis of ?-conjugated oligomer that can form metallo polymers. ACTA ACUST UNITED AC 2002. [DOI: 10.1002/pola.10477] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
2236
|
Fenniri H, Deng BL, Ribbe AE. Helical rosette nanotubes with tunable chiroptical properties. J Am Chem Soc 2002; 124:11064-72. [PMID: 12224954 DOI: 10.1021/ja026164s] [Citation(s) in RCA: 250] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
On the basis of transmission electron microscopy (TEM), dynamic light scattering (DLS), small-angle X-ray scattering (SAXS), and circular dichroism (CD) studies, compound 1 was shown to exist mainly in two states: (a) At high concentration (> or =1 mM, in methanol), 1 undergoes hierarchical self-assembly to generate rosette nanotubes with approximately 4 nm diameter and a concentration-dependent hydrodynamic radius in the range 10-100 nm. Under these conditions, addition of a chiral amino acid promoter (L-Ala), that binds to the crown ether moiety of 1 via electrostatic interactions, promotes a rapid transition (k(0) approximately equal 0.48 s(-1), for [1] = 0.046 mM, [L-Ala] = 2.8 mM) from racemic to chiral rosette nanotubes with predefined helicities as indicated by the resulting induced circular dichroism (ICD). (b) At low concentration (< or =0.04 mM, in methanol), 1 exists mainly in a nonassembled state as shown by TEM and DLS. Addition of L-Ala in this case triggers a relatively slow (k(0) approximately equal 0.07 s(-1) for [1] = 0.04 mM, [L-Ala] = 2.4 mM) sequence of supramolecular reactions leading to the hierarchical self-assembly of rosette nanotubes with predefined helicities. Under both conditions a and b, the kinetic data unveiled the intrinsic ability of the rosette nanotubes to promote their own formation (autocatalysis). The degree of chiral induction was found to depend dramatically upon the chemical structure of the promoter. This process appears also to follow an all-or-none response, as the vast majority of the crown ether sites must be occupied with a promoter for a complete transition to chiral nanotubes to take place. Finally, both supramolecular pathways a and b offer an efficient approach for the preparation of helical rosette nanotubes with tunable chiroptical properties and may also be viewed as a process by which a predefined set of physical and chemical properties that characterizes a molecular promoter is expressed at the macromolecular level.
Collapse
Affiliation(s)
- Hicham Fenniri
- Contribution from the 1393 H. C. Brown Chemistry Laboratory, Purdue University, West Lafayette, Indiana 47907-1393, USA.
| | | | | |
Collapse
|
2237
|
Saalwächter K, Schnell I. REDOR-based heteronuclear dipolar correlation experiments in multi-spin systems: rotor-encoding, directing, and multiple distance and angle determination. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2002; 22:154-187. [PMID: 12469809 DOI: 10.1006/snmr.2002.0079] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We review a variety of recently developed 1H-X heteronuclear recoupling techniques, which rely only on the homonuclear decoupling efficiency of very-fast magic-angle spinning. All these techniques, which are based on the simple rotational-echo, double-resonance (REDOR) approach for heteronuclear recoupling, are presented in a common context. Advantages and possibilities with respect to the complementary application of conventionally X and 1H-inversely detected variants are discussed in relation to the separability and analysis of multiple couplings. We present an improved and more sensitive approach to the determination of 1H-X dipolar couplings by spinning-sideband analysis, termed REREDOR, which is applicable to XHn groups in rigid and mobile systems and bears some similarity to more elaborate separated local-field methods. The estimation of medium-range 1H-X distances by analyzing signal intensities in two-dimensional REDOR correlation spectra in a model-free way is also discussed. More specifically, we demonstrate the possibility of combined distance and angle determination in H-X-H or X-H-X three-spin systems by asymmetric recoupling schemes and spinning-sideband analysis. Finally, an 1H-X correlation experiment is introduced which accomplishes high sensitivity by inverse (1H) detection and is therefore applicable to samples with 15N in natural abundance.
Collapse
Affiliation(s)
- Kay Saalwächter
- Institut für Makromolekulare Chemie, Universität Freiburg. Stefan-Meier-Str. 31, D-79104 Freiburg, Germany.
| | | |
Collapse
|
2238
|
Müller W, Müller U, Mieden-Gundert G, Vögtle F, Lescanne M, Heuzé K, D'Aléo A, Fages F. Salts of 4-Substituted Dipicolinic Acid Derivatives − Very Low Molecular Mass Gelators of Aqueous DMSO. European J Org Chem 2002. [DOI: 10.1002/1099-0690(200209)2002:17<2891::aid-ejoc2891>3.0.co;2-f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
2239
|
Maji SK, Banerjee A, Drew MG, Haldar D, Banerjee A. Self-assembly of a tetrapeptide in which a unique supramolecular helical structure is formed via intermolecular hydrogen bonding in the solid state. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01521-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
2240
|
Yamauchi K, Lizotte JR, Hercules DM, Vergne MJ, Long TE. Combinations of microphase separation and terminal multiple hydrogen bonding in novel macromolecules. J Am Chem Soc 2002; 124:8599-604. [PMID: 12121101 DOI: 10.1021/ja020123e] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and characterization of terminal multiple hydrogen-bonded (MHB) polymers, such as poly(styrene) (PS), poly(isoprene) (PI), and microphase separated PS-b-PI block copolymers, possessing controlled molecular weights and narrow molecular distributions are described. Hydroxyl-terminated polymeric precursors were prepared using living anionic polymerization and subsequent quantitative termination with ethylene oxide. MHB polymers were synthesized in a controlled fashion via end-group modification of these well-defined macromolecular alcohols with excess isophorone diisocyanate and subsequent derivatization of the isocyanate-terminated polymeric intermediate with methyl isocytosine. The glass transition temperatures of the terminal MHB polymers were reproducibly higher than both nonfunctionalized and hydroxyl-terminated polymers at nearly equivalent number average molecular weights. Thin-layer chromatography analysis indicated that the interaction of terminal MHB polymers with silica was stronger as compared to both nonfunctionalized and hydroxyl-terminated polymers. Rheological characterization indicated that the melt viscosity at constant shear rate for various MHB polymers was more than 100 times higher than those for nonfunctionalized and hydroxyl-terminated polymers. Interestingly, the melt viscosity of MHB polymers was higher than those of nonfunctionalized polymers with twice the number average molecular weight. In addition, DSC and rheological characterization also suggested that terminal MHB polymers formed aggregates and not simple dimers in the melt state, and the aggregates were observed to completely dissociate at 80 degrees C.
Collapse
Affiliation(s)
- Koji Yamauchi
- Department of Chemistry and Polymeric Materials and Interfaces Laboratories, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061-0212, USA
| | | | | | | | | |
Collapse
|
2241
|
Haldar D, Maji SK, Drew MG, Banerjee A, Banerjee A. Self-assembly of a short peptide monomer into a continuous hydrogen bonded supramolecular helix: the crystallographic signature. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01050-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
2242
|
van der Gucht J, Besseling NAM, Cohen Stuart MA. Surface forces, supramolecular polymers, and inversion symmetry. J Am Chem Soc 2002; 124:6202-5. [PMID: 12022855 DOI: 10.1021/ja0125422] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of supramolecular equilibrium polymers on surface forces are studied by both a phenomenological Landau type analysis and a molecular model based on a Bethe-Guggenheim approximation. We point out that surface forces brought about by equilibrium polymers may be completely different from what can be found with "ordinary" polymers. The new feature is the role of inversion (a)symmetry or "directionality" of the associating unit molecules ("monomers"). Symmetric B-B monomers (where B denotes a self-complementary binding group) give rise to nondirectional chains and lead to attractive forces between similar surfaces. Asymmetric A-D monomers (where A and D denote complementary acceptor and donor groups, respectively) produce directional chains and can cause strong repulsion. The range of the attractive force has a maximum at intermediate concentration, while the range of the repulsive force increases over the whole concentration range.
Collapse
Affiliation(s)
- Jasper van der Gucht
- Dutch Polymer Institute/Wageningen University, Laboratory of Physical Chemistry and Colloid Science, Dreijenplein 6, 6703 HB Wageningen, The Netherlands.
| | | | | |
Collapse
|
2243
|
|
2244
|
|
2245
|
Lehn JM. Toward complex matter: supramolecular chemistry and self-organization. Proc Natl Acad Sci U S A 2002; 99:4763-8. [PMID: 11929970 PMCID: PMC122664 DOI: 10.1073/pnas.072065599] [Citation(s) in RCA: 926] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Jean-Marie Lehn
- Institut de Science et d'Ingénierie Supramoléculaires, Université Louis Pasteur, 67000 Strasbourg, France.
| |
Collapse
|
2246
|
Abstract
Beyond molecular chemistry based on the covalent bond, supramolecular chemistry aims at developing highly complex chemical systems from components interacting through noncovalent intermolecular forces. Over the past quarter century, supramolecular chemistry has grown into a major field and has fueled numerous developments at the interfaces with biology and physics. Some of the conceptual advances and future challenges are profiled here.
Collapse
Affiliation(s)
- Jean-Marie Lehn
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université Louis Pasteur, 67000 Strasbourg, and Collège de France, 75005 Paris, France.
| |
Collapse
|
2247
|
Affiliation(s)
- Takashi Kato
- Department of Chemistry and Biotechnology, School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo 113-8656, Japan
| |
Collapse
|
2248
|
Dobrawa R, Würthner F. Photoluminescent supramolecular polymers: metal-ion directed polymerization of terpyridine-functionalized perylene bisimide dyes. Chem Commun (Camb) 2002:1878-9. [PMID: 12271654 DOI: 10.1039/b205478g] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Perylene bisimide dyes bearing one and two 2,2':6',2"-terpyridine receptor groups were prepared and the structural and optical properties of their Zn2+ complexes were investigated by 1H NMR and fluorescence experiments.
Collapse
Affiliation(s)
- Rainer Dobrawa
- Abteilung Organische Chemie II, Universität Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | | |
Collapse
|