151
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X-ray photoelectron spectroscopy characterization of gold nanoparticles functionalized with amine-terminated alkanethiols. Biointerphases 2012; 6:98. [PMID: 21974680 DOI: 10.1116/1.3622481] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Gold nanoparticles (AuNPs) functionalized with a short chain amine-terminated alkanethiol (HS-(CH(2))(2)NH(2) or C2 NH(2)-thiol) are prepared via a direct synthesis method and then ligand-exchanged with a long chain amine-terminated alkanethiol (HS-(CH(2))(11)NH(2) or C11 NH(2)-thiol). Transmission electron microscopy analysis showed the AuNPs were relatively spherical with a median diameter of 24.2 ± 4.3 nm. X-ray photoelectron spectroscopy was used to determine surface chemistry of the functionalized and purified AuNPs. The ligand-exchange process was monitored within the time range from 30 min to 61 days. By the fourth day of exchange all the C2 NH(2)-thiol molecules had been replaced by C11 NH(2)-thiol molecules. C11 NH(2)-thiol molecules continued to be incorporated into the C11 NH(2) self-assembled monolayer between days 4 and 14 of ligand-exchange. As the length of the exchange time increased, the functionalized AuNPs became more stable against aggregation. The samples were purified by a centrifugation and resuspension method. The C2 NH(2) covered AuNPs aggregated immediately when purification was attempted. The C11 NH(2) covered AuNPs could be purified with minimal or no aggregation. Small amounts of unbound thiol (∼15%) and oxidized sulfur (∼20%) species were detected on the ligand-exchanged AuNPs. Some of the unbound thiol and all of the oxidized sulfur could be removed by treating the functionalized AuNPs with HCl.
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152
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Kikkawa Y, Omori K, Takahashi M, Kanesato M, Hiratani K. Effects of alkyl chain length, solvent and tandem Claisen rearrangement on two-dimensional structures of noncyclic isobutenyl compounds: scanning tunnelling microscopic study. Org Biomol Chem 2012; 10:8087-94. [DOI: 10.1039/c2ob26015h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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153
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De Cat I, Gobbo C, Van Averbeke B, Lazzaroni R, De Feyter S, van Esch J. Controlling the Position of Functional Groups at the Liquid/Solid Interface: Impact of Molecular Symmetry and Chirality. J Am Chem Soc 2011; 133:20942-50. [DOI: 10.1021/ja209018u] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Inge De Cat
- Department of Chemistry, Division of Molecular Imaging and Photonics, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Cristian Gobbo
- Department of Chemistry, Laboratory of Self-assembling Systems, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
| | - Bernard Van Averbeke
- Laboratory for Chemistry of Novel Materials, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Roberto Lazzaroni
- Laboratory for Chemistry of Novel Materials, Université de Mons, Place du Parc 20, 7000 Mons, Belgium
| | - Steven De Feyter
- Department of Chemistry, Division of Molecular Imaging and Photonics, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Jan van Esch
- Department of Chemistry, Laboratory of Self-assembling Systems, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands
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154
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Baldelli S, Bao J, Wu W, Pei SS. Sum frequency generation study on the orientation of room-temperature ionic liquid at the graphene–ionic liquid interface. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.09.084] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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155
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Srisombat L, Jamison AC, Lee TR. Stability: A key issue for self-assembled monolayers on gold as thin-film coatings and nanoparticle protectants. Colloids Surf A Physicochem Eng Asp 2011. [DOI: 10.1016/j.colsurfa.2011.09.020] [Citation(s) in RCA: 156] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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156
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Zhang Y, Chu Z, Shi L, Jin W. Effect of temperature-controlled poly(diallyldimethylammonium chloride) on morphology of self-assembled Prussian Blue electrode and its high detection sensitivity of hydrogen peroxide. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.05.134] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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157
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Gómez-Gallego M, Martín-Ortiz M, Sierra MA. Concerning the Electronic Control of Torsion Angles in Biphenyls. European J Org Chem 2011. [DOI: 10.1002/ejoc.201100874] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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158
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Moy CL, Kaliappan R, McNeil AJ. Aryl Trihydroxyborate Salts: Thermally Unstable Species with Unusual Gelation Abilities. J Org Chem 2011; 76:8501-7. [DOI: 10.1021/jo201353j] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cheryl L. Moy
- Department of Chemistry and Macromolecular Science and Engineering Program, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Raja Kaliappan
- Department of Chemistry and Macromolecular Science and Engineering Program, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Anne J. McNeil
- Department of Chemistry and Macromolecular Science and Engineering Program, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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159
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Ramin L, Jabbarzadeh A. Odd-even effects on the structure, stability, and phase transition of alkanethiol self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:9748-59. [PMID: 21749126 DOI: 10.1021/la201467b] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Molecular dynamics simulations were conducted to predict the structural properties and phase transition temperatures of n-alkanethiols CH(3)(CH(2))(n-1)SH (Cn, 4 ≤ n ≤ 22) self-assembled monolayers (SAMs) on Au (111) surfaces. We studied the effects of chain length on the structural properties, including tilt and orientation angles, and on phase transition temperature. We found clear dependence of the structural properties, on both the number of carbon atoms, n; and on n being odd or even. Alkanethiols with n ≤ 7 show liquid-like behavior and large rotational mobility, whereas those with n ≥ 12 are well-ordered and stable. For 12 ≤ n ≤ 15, odd-even effects are observed, where for n = odd, larger tilt angles, oriented in the direction of their next next nearest neighbor (NNNN), and for n = even, lower tilt angles, mostly tilted toward next nearest neighbor (NNN), were observed. For 15 ≤ n ≤ 19, we find tilt angle and orientation to be independent of n. For all alkanethiols, a gradual decrease of the tilt angle occurred by increasing the temperature from 300 to 420 K. Order-disorder phase transitions occurred at a certain temperature. This was signified by abrupt instabilities in the tilt orientation angle. This transition temperature showed an enhancement of ∼67-100 °C over the melting point of the corresponding n-alkane bulk system. This enhancement depended on n, and was larger for n = odd. Overall, we found that odd alkanethiols show better structural and thermal stability, and smaller gauche defects.
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Affiliation(s)
- Leyla Ramin
- School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006, Australia
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160
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Zhu P, Ma P, Wang Y, Wang Q, Zhao X, Zhang X. Organic Nanostructures with Controllable Morphology Fabricated from Ferrocene-Porphyrin Derivatives: Effect of Metal-Ligand Coordination on the Morphology, Dimensions, and Semiconductor Properties of Self-Assembled Nanostructures. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201100421] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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161
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Techane S, Baer DR, Castner DG. Simulation and modeling of self-assembled monolayers of carboxylic acid thiols on flat and nanoparticle gold surfaces. Anal Chem 2011; 83:6704-12. [PMID: 21744862 DOI: 10.1021/ac201175a] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Quantitative analysis of the 16-mercaptohexadecanoic acid self-assembled monolayer (C16 COOH-SAM) layer thickness on gold nanoparticles (AuNPs) was performed using simulation of electron spectra for surface analysis (SESSA) software and X-ray photoelectron spectroscopy (XPS) experimental measurements. XPS measurements of C16 COOH-SAMs on flat gold surfaces were made at nine different photoelectron emission angles (5-85° in 10° increments), corrected using geometric weighting factors and then summed together to approximate spherical AuNPs. The SAM thickness and relative surface roughness (RSA) in SESSA were optimized to determine the best agreement between simulated and experimental surface composition. On the basis of the glancing-angle results, it was found that inclusion of a hydrocarbon-contamination layer on top the C16 COOH-SAM was necessary to improve the agreement between the SESSA and XPS results. For the 16 COOH-SAMs on flat Au surfaces, using a SAM thickness of 1.1 Å/CH(2) group, an RSA of 1.05, and a 1.5 Å CH(2)-contamination overlayer (total film thickness = 21.5 Å) for the SESSA calculations provided the best agreement with the experimental XPS data. After applying the appropriate geometric corrections and summing the SESSA flat-surface compositions, the best fit results for the 16 COOH-SAM thickness and surface roughness on the AuNPs indicated a slightly thinner overlayer with parameters of 0.9 Å/CH(2) group in the SAM, an RSA of 1.06 RSA, and a 1.5 Å CH(2)-contamination overlayer (total film thickness = 18.5 Å). The 3 Å difference in SAM thickness between the flat Au and AuNP surfaces suggests that the alkyl chains of the SAM are slightly more tilted or disordered on the AuNP surfaces.
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Affiliation(s)
- Sirnegeda Techane
- National ESCA and Surface Analysis Center for Biomedical Problems, Department of Chemical Engineering, P.O. Box 351750, University of Washington, Seattle, Washington 98195, USA
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162
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Khan MK, Sundararajan PR. Effects of Carbon Atom Parity and Alkyl Side Chain Length on the Crystallization and Morphology of Biscarbamates, A Set of Model Compounds for Polyurethanes. J Phys Chem B 2011; 115:8696-706. [DOI: 10.1021/jp203790f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Mostofa Kamal Khan
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
| | - Pudupadi R. Sundararajan
- Department of Chemistry, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6, Canada
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163
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Braga D, d'Agostino S, Dichiarante E, Maini L, Grepioni F. Dealing with Crystal Forms (The Kingdom of Serendip?). Chem Asian J 2011; 6:2214-23. [DOI: 10.1002/asia.201100084] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2011] [Indexed: 11/10/2022]
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164
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Dai K, Nomoto K, Ueno S, Tomono K, Miyamura K. Odd–Even Effect and Unusual Behavior of Dodecyl-Substituted Analogue Observed in the Crystal Structure of Alkyltrimethylammonium–[Ni(dmit)2]−Salts. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2011. [DOI: 10.1246/bcsj.20100306] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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165
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Thuo MM, Reus WF, Nijhuis CA, Barber JR, Kim C, Schulz MD, Whitesides GM. Odd−Even Effects in Charge Transport across Self-Assembled Monolayers. J Am Chem Soc 2011; 133:2962-75. [DOI: 10.1021/ja1090436] [Citation(s) in RCA: 164] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Martin M. Thuo
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - William F. Reus
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Christian A. Nijhuis
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543
| | - Jabulani R. Barber
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Choongik Kim
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - Michael D. Schulz
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
| | - George M. Whitesides
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138, United States
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166
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Abstract
We put forward an impedometric protein-based biosensor platform suitable for point-of-care diagnostics. A hand-held scale impedance reader system is described for the detection of corresponding physiochemical changes as the immobilized proteins bind to the analyte molecules in the proximity of the microfabricated electrodes. Specifically, we study the viability of this approach for glucose biosensing purposes using genetically engineered glucokinase as receptor proteins. The proposed reagent-less biosensor offers a high sensitivity of 0.5 mM glucose concentration level in the physiologically relevant range of 0.5 mM to 7.5 mM with less than 10 s response time.
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167
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Jeon S, Jo Y, Kim KJ, Jun Y, Han CH. High performance dye-sensitized solar cells with alkylpyridinium iodide salts in electrolytes. ACS APPLIED MATERIALS & INTERFACES 2011; 3:512-516. [PMID: 21268664 DOI: 10.1021/am101093b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Pyridinium iodide salts, which are competitive to the conventional imidazolium iodide salts, have been used for dye-sensitized solar cells as iodide sources and ionic conductivities. Pyridinium iodide series are easy to prepare and less expensive than the imidazolium series salts. In this research, quite comparable efficiencies were obtained from electrolytes with pyridinium iodide salts. For the experiments, pyridinium salts with a few different alkyl chains are applied. When a pyridinium head is modified to picolinium, which has a methyl group on the pyridinium head, a noticeable V(oc) drop has been observed. However, the length of the alkyl chains on the pyridinium head does not affect V(oc) effectively. The odd-numbered alkyl chains showed slightly lower V(oc) compared to that of the even-numbered alkyl chains. Finally, the performances of the cells with pyridinium salts are compared to those of the conventional cells with imidazolium salts.
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Affiliation(s)
- Semina Jeon
- Photovoltaic Research Center, Korea Institute of Energy Research, 71-2, Jangdong, Yuseong, Daejeon 305-343, Republic of Korea
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168
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Vervaecke F, Wyczawska S, Cyganik P, Bastiaansen J, Postawa Z, Silverans RE, Vandeweert E, Lievens P. Odd-Even Effects in Ion-Beam-Induced Desorption of Biphenyl-Substituted Alkanethiol Self-Assembled Monolayers. Chemphyschem 2010; 12:140-4. [DOI: 10.1002/cphc.201000610] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Indexed: 11/06/2022]
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169
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Das A, Ghosh S. Contrasting Self-Assembly and Gelation Properties among Bis-urea- and Bis-amide-Functionalised Dialkoxynaphthalene (DAN) π Systems. Chemistry 2010; 16:13622-8. [DOI: 10.1002/chem.201002208] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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170
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Mali KS, Lava K, Binnemans K, De Feyter S. Hydrogen Bonding Versus van der Waals Interactions: Competitive Influence of Noncovalent Interactions on 2D Self-Assembly at the Liquid-Solid Interface. Chemistry 2010; 16:14447-58. [DOI: 10.1002/chem.201001653] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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171
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Phollookin C, Wacharasindhu S, Ajavakom A, Tumcharern G, Ampornpun S, Eaidkong T, Sukwattanasinitt M. Tuning Down of Color Transition Temperature of Thermochromically Reversible Bisdiynamide Polydiacetylenes. Macromolecules 2010. [DOI: 10.1021/ma101264k] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chaiwat Phollookin
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University Bangkok, 10330, Thailand
| | - Sumrit Wacharasindhu
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University Bangkok, 10330, Thailand
| | - Anawat Ajavakom
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University Bangkok, 10330, Thailand
| | - Gamolwan Tumcharern
- Thailand National Nanotechnology Center, National Science and Technology Development Agency Patumthanee, 12120, Thailand
| | - Sasikarn Ampornpun
- Program of Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Thichamporn Eaidkong
- Program of Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Mongkol Sukwattanasinitt
- Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University Bangkok, 10330, Thailand
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172
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Kikkawa Y, Koyama E, Aoyagi M, Schneider N, Takahashi M, Fujiwara K, Kanesato M. Metallation of bipyridine derivatives substituted at meta position by alkyl chains: effects on the 2D structures. Supramol Chem 2010. [DOI: 10.1080/10610278.2010.500734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Yoshihiro Kikkawa
- a Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 4, 1-1-1 Higashi , Tsukuba, Ibaraki, 305-8562, Japan
| | - Emiko Koyama
- a Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 4, 1-1-1 Higashi , Tsukuba, Ibaraki, 305-8562, Japan
| | - Masaru Aoyagi
- b Nanotube Research Center, National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki, 305-8565, Japan
| | - Nathanaëlle Schneider
- a Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 4, 1-1-1 Higashi , Tsukuba, Ibaraki, 305-8562, Japan
| | - Mayuko Takahashi
- a Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 4, 1-1-1 Higashi , Tsukuba, Ibaraki, 305-8562, Japan
| | - Kyoko Fujiwara
- a Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 4, 1-1-1 Higashi , Tsukuba, Ibaraki, 305-8562, Japan
| | - Masatoshi Kanesato
- a Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 4, 1-1-1 Higashi , Tsukuba, Ibaraki, 305-8562, Japan
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173
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Eckermann AL, Feld DJ, Shaw JA, Meade TJ. Electrochemistry of redox-active self-assembled monolayers. Coord Chem Rev 2010; 254:1769-1802. [PMID: 20563297 PMCID: PMC2885823 DOI: 10.1016/j.ccr.2009.12.023] [Citation(s) in RCA: 359] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Redox-active self-assembled monolayers (SAMs) provide an excellent platform for investigating electron transfer kinetics. Using a well-defined bridge, a redox center can be positioned at a fixed distance from the electrode and electron transfer kinetics probed using a variety of electrochemical techniques. Cyclic voltammetry, AC voltammetry, electrochemical impedance spectroscopy, and chronoamperometry are most commonly used to determine the rate of electron transfer of redox-activated SAMs. A variety of redox species have been attached to SAMs, and include transition metal complexes (e.g., ferrocene, ruthenium pentaammine, osmium bisbipyridine, metal clusters) and organic molecules (e.g., galvinol, C(60)). SAMs offer an ideal environment to study the outer-sphere interactions of redox species. The composition and integrity of the monolayer and the electrode material influence the electron transfer kinetics and can be investigated using electrochemical methods. Theoretical models have been developed for investigating SAM structure. This review discusses methods and monolayer compositions for electrochemical measurements of redox-active SAMs.
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174
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Franz AW, Stoycheva S, Himmelhaus M, Müller TJJ. Synthesis, electronic properties and self-assembly on Au{111} of thiolated (oligo)phenothiazines. Beilstein J Org Chem 2010; 6. [PMID: 20703376 PMCID: PMC2919263 DOI: 10.3762/bjoc.6.72] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2010] [Accepted: 06/02/2010] [Indexed: 11/23/2022] Open
Abstract
(Oligo)phenothiazinyl thioacetates, synthesized by a one-pot sequence, are electrochemically oxidizable and highly fluorescent. SAMs can be readily formed from thiols prepared by in situ deprotection of the thioacetates in the presence of a gold-coated silicon wafer. Monolayer formation is confirmed by ellipsometry and the results compared to those obtained by force field and DFT calculations.
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Affiliation(s)
- Adam W Franz
- Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstr. 1, D-40225 Düsseldorf, Germany
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175
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Sunday D, Curras-Medina S, Green DL. Impact of Initiator Spacer Length on Grafting Polystyrene from Silica Nanoparticles. Macromolecules 2010. [DOI: 10.1021/ma1004259] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Daniel Sunday
- Department of Chemical Engineering, University of Virginia, 102 Engineers Way, Charlottesville, Virginia 22904
| | - Sara Curras-Medina
- Department of Chemical Engineering, University of Virginia, 102 Engineers Way, Charlottesville, Virginia 22904
| | - David L. Green
- Department of Chemical Engineering, University of Virginia, 102 Engineers Way, Charlottesville, Virginia 22904
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176
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Barriet D, Chinwangso P, Lee TR. Can cyclopropyl-terminated self-assembled monolayers on gold be used to mimic the surface of polyethylene? ACS APPLIED MATERIALS & INTERFACES 2010; 2:1254-1265. [PMID: 20423144 DOI: 10.1021/am1001585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
This paper describes the formation of a new series of monolayer films generated by the self-assembly of omega-cyclopropylalkanethiols, CyPr(CH(2))(n)SH (n = 9-13), onto the surface of gold. Procedures used to prepare the omega-cyclopropylalkanethiol adsorbates are also reported. Methyl-, vinyl-, and isopropyl-terminated self-assembled monolayers (SAMs) were also prepared and used as reference films to evaluate the structure and properties of the new cyclopropyl-terminated films. Ellipsometry and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS) were used to examine the structure of the SAMs. A small but systematically lower thickness of the new films compared to that of analogous methyl-terminated SAMs was observed. Also, the orientation of the ring with respect to the surface normal was observed to vary systematically with the number of methylene groups in the adsorbate backbone (i.e., odd vs even chain lengths). Measurements of wettability by contact angle goniometry also revealed a small but reproducible "odd-even" effect for all contacting liquids used, except hexadecane, which almost completely wet the surfaces (theta(a) = 10-13 degrees ). When compared to the wettability data obtained from methyl- and isopropyl-terminated SAMs, the wettability data obtained from the cyclopropyl-terminated SAMs suggest that these films offer an increased density of atomic contacts per unit area across the surface, and thus enhanced attractive interactions with contacting liquids. Comparison of the wettabilities of vinyl-terminated and cyclopropyl-terminated films is complicated by dipole-induced dipole interactions and/or pi-pi interactions between the surfaces and the probe liquids. Furthermore, the significantly similar wettabilities of the cyclopropyl-terminated SAMs and the surface of polyethylene suggests that these SAMs (and perhaps other SAMs with judiciously designed tailgroups) can be used to mimic the interfacial properties of polymeric materials without complications arising from surface reconstruction.
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Affiliation(s)
- David Barriet
- Department of Chemistry, University of Houston, Houston, TX 77204-5003, USA
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177
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Smulders MMJ, Stals PJM, Mes T, Paffen TFE, Schenning APHJ, Palmans ARA, Meijer EW. Probing the limits of the majority-rules principle in a dynamic supramolecular polymer. J Am Chem Soc 2010; 132:620-6. [PMID: 20014837 DOI: 10.1021/ja9080875] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
By systematic variation of the chemical structure of benzene-1,3,5-tricarboxamide (BTA) derivatives, the effect of chemical structure on the amplification of chirality was studied and quantified. In combination with temperature-dependent amplification experiments, the limits of the majority-rules principle were also investigated. For all BTA derivatives a high, constant helix reversal penalty was determined, which is related to the intermolecular hydrogen bonds that are present in all studied derivatives. For asymmetrically substituted BTA derivatives an odd-even effect was found in the degree of chiral amplification when changing the position of the stereogenic center with respect to the amide functionality. It was found that the mismatch penalty could be directly related to the number of stereocenters present in the molecules. Increasing this number from one to three resulted in an increase in this energy penalty while leaving the helix reversal penalty unaffected. For the majority-rules principle this implies that a single stereocenter present in the molecule contains sufficient chiral information at the molecular level to result in a chirally amplified state at the supramolecular level. Further evidence that the mismatch penalty is directly related to the number of stereocenters was obtained from mixed majority-rules experiments where two BTA derivatives with different numbers of stereocenters with opposite stereoconfiguration were studied in a majority-rules experiment. Finally, the ultimate limits of chiral amplification for the majority-rules principle were investigated, revealing that, given a certain helix reversal penalty, there is an optimum to which the mismatch penalty can be reduced while also enhancing the degree of chiral amplification. Temperature-dependent majority-rules experiments could indeed confirm these simulations. These findings show the relevance of both energy penalties when trying to enhance the degree of chiral amplification for the majority-rules principle in a one-dimensional helical supramolecular polymer.
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Affiliation(s)
- Maarten M J Smulders
- Laboratory of Macromolecular and Organic Chemistry and Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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178
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Kikkawa Y, Koyama E, Tsuzuki S, Fujiwara K, Kanesato M. Bipyridine derivatives at a solid/liquid interface: effects of the number and length of peripheral alkyl chains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:3376-3381. [PMID: 20175574 DOI: 10.1021/la903156m] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Bipyridine derivatives (bpys) with various number and length of peripheral alkyl chains (with carbon numbers of n = 11-17) were synthesized, and their self-assembled monolayers were observed by scanning tunneling microscopy (STM) at a 1-phenyloctane/highly oriented pyrolytic graphite (HOPG) interface. The effects of the number, the substitution position, and the length of alkyl chains on the two-dimensional structures were systematically studied. Bpys substituted by a single alkyl chain in the p-position on each side adopted an almost linear form with zigzag-type alignment of the pi-conjugated unit, whereas, in the case of m-substitution, the bpys showed Z-shaped morphology with interdigitated alkyl chains. In both cases, no odd-even alkyl chain length effects were observed. The bpys with double alkyl chains at m- and p-positions displayed odd-even alkyl chain effects, suggesting that the formation of two-dimensional structure is dominated by the interactions between alkyl chains. Bpys with triple alkyl chains at o-, m-, and p-positions also showed odd-even alkyl chain effects, but only for the higher number of carbon atoms in the alkyl chain unit (n = 14-17). These results indicate that concerted intermolecular interactions of the alkyl chain unit introduce the odd-even chain length effect on the self-assembled two-dimensional structure. After coordination of PdCl(2), odd-even effects were quenched, and bpys were converged into the same lamellar structure, in which the molecules are almost linear. All the structural differences due to the odd-even alkyl chain length effect were explained in terms of intermolecular and molecule-substrate interactions.
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Affiliation(s)
- Yoshihiro Kikkawa
- National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8562, Japan.
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179
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Katash I, Luo X, Sukenik CN. Sulfonation of alkyl phenyl ether self-assembled monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:1765-1775. [PMID: 20047305 DOI: 10.1021/la902093x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The sulfonation of phenyl ether decorated self-assembled monolayers (SAMs) was studied with an eye toward creating surfaces with a particularly high negative charge density based on a close-packed array of phenyl rings with more than one sulfonic acid group per molecule. The product distribution and kinetics of this process were studied by ultraviolet, infrared, and photoelectron spectroscopies and by monitoring changes in the thickness and wetting properties of the SAM. The sulfonation chemistry could be effected without undermining monolayer integrity and the isomer distribution of ortho- and para-monosulfonated material, along with the percentages of mono- and disulfonated molecules could be established throughout the process. As doubly sulfonated molecules appeared, the reaction slowed drastically. Ultimately, sulfonation stops completely with approximately 60% of the molecules disulfonated and 20% each of the two monosulfonated isomers. This striking constraint on monolayer reactivity and the relationship between the surface chemistry and variations in SAM structure are discussed.
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Affiliation(s)
- Irit Katash
- Department of Chemistry and Institute of Nanotechnology and Advanced Materials, Bar Ilan University, Ramat Gan 52900, Israel
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180
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Cecchet F, Lis D, Guthmuller J, Champagne B, Caudano Y, Silien C, Addin Mani A, Thiry PA, Peremans A. Orientational Analysis of Dodecanethiol and p-Nitrothiophenol SAMs on Metals with Polarisation-Dependent SFG Spectroscopy. Chemphyschem 2010; 11:607-15. [DOI: 10.1002/cphc.200900733] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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181
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Zhang X, Wang Q, Wu L, Lv W, Lu J, Bian Y, Jiang J. Organic Nanostructures with Controllable Morphology Fabricated from Mixed (Phthalocyaninato)(porphyrinato) Europium Double-Decker Complexes. J Phys Chem B 2010; 114:1233-40. [DOI: 10.1021/jp9067608] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiaomei Zhang
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Quanbo Wang
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Lizhen Wu
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Wei Lv
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jitao Lu
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Yongzhong Bian
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
| | - Jianzhuang Jiang
- Department of Chemistry, Shandong University, Jinan 250100, China, and Department of Chemistry, University of Science and Technology Beijing, Beijing 100083, China
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182
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Braga D, Dichiarante E, Palladino G, Grepioni F, Chierotti MR, Gobetto R, Pellegrino L. Remarkable reversal of melting point alternation by co-crystallization. CrystEngComm 2010. [DOI: 10.1039/c0ce00253d] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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183
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Omori K, Kikkawa Y, Kanesato M, Hiratani K. Fabrication and transformation of novel two-dimensional tripod structures: structural modulation by alkyl chain length and tandem Claisen rearrangement. Chem Commun (Camb) 2010; 46:8008-10. [DOI: 10.1039/c0cc02963g] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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184
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185
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Chesneau F, Schüpbach B, Szelągowska-Kunstman K, Ballav N, Cyganik P, Terfort A, Zharnikov M. Self-assembled monolayers of perfluoroterphenyl-substituted alkanethiols: specific characteristics and odd–even effects. Phys Chem Chem Phys 2010; 12:12123-37. [DOI: 10.1039/c0cp00317d] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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186
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Lee HH, Ruzele Z, Malysheva L, Onipko A, Gutés A, Björefors F, Valiokas R, Liedberg B. Long-chain alkylthiol assemblies containing buried in-plane stabilizing architectures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:13959-13971. [PMID: 19791763 DOI: 10.1021/la901668u] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A series of alkylthiol compounds were synthesized to study the formation and structure of complex self-assembled monolayers (SAMs) consisting of interchanging structural modules stabilized by intermolecular hydrogen bonds. The chemical structure of the synthesized compounds, HS(CH(2))(15)CONH(CH(2)CH(2)O)(6)CH(2)CONH-X, where X refers to the extended chains of either -(CH(2))(n)CH(3) or -(CD(2))(n)CD(3), with n = 0, 1, 7, 8, 15, was confirmed by NMR and elemental analysis. The formation of highly ordered, methyl-terminated SAMs on gold from diluted ethanolic solutions of these compounds was revealed using contact angle goniometry, null ellipsometry, cyclic voltammetry, and infrared reflection absorption spectroscopy. The experimental work was complemented with extensive DFT modeling of infrared spectra and molecular orientation. New assignments were introduced for both nondeuterated and deuterated compounds. The latter set of compounds also served as a convenient tool to resolve the packing, conformation, and orientation of the buried and extended modules within the SAM. Thus, it was shown that the lower alkyl portion together with the hexa(ethylene glycol) portion is stabilized by the two layers of lateral hydrogen bonding networks between the amide groups, and they provide a structurally robust support for the extended alkyls. The presented system can be considered to be an extension of the well-known alkyl SAM platform, enabling precise engineering of nanoscopic architectures on the length scale from a few to approximately 60 A for applications such as cell membrane mimetics, molecular nanolithography, and so forth.
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Affiliation(s)
- Hung-Hsun Lee
- Division of Molecular Physics, Department of Physics, Chemistry and Biology, Linköping University, 58183 Linköping, Sweden
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187
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Pokroy B, Chernow VF, Aizenberg J. Crystallization of malonic and succinic acids on SAMs: toward the general mechanism of oriented nucleation on organic monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:14002-6. [PMID: 19769350 DOI: 10.1021/la902739q] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Self-assembled monolayers (SAMs) were shown to induce very specific oriented growth of simple organic and inorganic crystals. Here we present a detailed study of the mechanism by which SAMs control the oriented nucleation by examining a more complex case of crystallization of bifunctional organic molecules. Malonic and succinic acids were grown on the SAMs of HS(CH(2))(10)CO(2)H and HS(CH(2))(11)CO(2)H supported on gold films. Each SAM induced a very controlled, specific orientation of the crystals. The preferred nucleating planes always exhibited an alignment of one of the carboxylic acid groups in the molecules of the growing crystal with the carboxylic acid groups on the surface of the SAMs. These results suggest that the translation of the structural information through the interface occurs by stereochemical registry such that the functional groups in the SAM play the role of an oriented surrogate layer for the nucleating crystal. These findings are very important to the understanding of the underlying principles by which various organic surfaces-and most probably also biological templates-control the crystallization process.
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Affiliation(s)
- Boaz Pokroy
- School of Engineering and Applied Sciences, Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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188
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Wei Q, Tajima K, Tong Y, Ye S, Hashimoto K. Surface-Segregated Monolayers: A New Type of Ordered Monolayer for Surface Modification of Organic Semiconductors. J Am Chem Soc 2009; 131:17597-604. [DOI: 10.1021/ja9057053] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qingshuo Wei
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan, PRESTO, Japan Science and Technology Agency (JST), and HASHIMOTO Light Energy Conversion Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Japan
| | - Keisuke Tajima
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan, PRESTO, Japan Science and Technology Agency (JST), and HASHIMOTO Light Energy Conversion Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Japan
| | - Yujin Tong
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan, PRESTO, Japan Science and Technology Agency (JST), and HASHIMOTO Light Energy Conversion Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Japan
| | - Shen Ye
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan, PRESTO, Japan Science and Technology Agency (JST), and HASHIMOTO Light Energy Conversion Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Japan
| | - Kazuhito Hashimoto
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan, Catalysis Research Center, Hokkaido University, Sapporo 001-0021, Japan, PRESTO, Japan Science and Technology Agency (JST), and HASHIMOTO Light Energy Conversion Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), Japan
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189
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Tao F, Bernasek SL, Xu GQ. Electronic and structural factors in modification and functionalization of clean and passivated semiconductor surfaces with aromatic systems. Chem Rev 2009; 109:3991-4024. [PMID: 19637925 DOI: 10.1021/cr8003532] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Feng Tao
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA
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190
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Wang Y, Neyman A, Arkhangelsky E, Gitis V, Meshi L, Weinstock IA. Self-Assembly and Structure of Directly Imaged Inorganic-Anion Monolayers on a Gold Nanoparticle. J Am Chem Soc 2009; 131:17412-22. [DOI: 10.1021/ja907815d] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yifeng Wang
- Department of Chemistry, Unit of Environmental Engineering, and Ilse Katz Institute for Nanoscale Science and Technology and Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Alevtina Neyman
- Department of Chemistry, Unit of Environmental Engineering, and Ilse Katz Institute for Nanoscale Science and Technology and Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Elizabeth Arkhangelsky
- Department of Chemistry, Unit of Environmental Engineering, and Ilse Katz Institute for Nanoscale Science and Technology and Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Vitaly Gitis
- Department of Chemistry, Unit of Environmental Engineering, and Ilse Katz Institute for Nanoscale Science and Technology and Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Louisa Meshi
- Department of Chemistry, Unit of Environmental Engineering, and Ilse Katz Institute for Nanoscale Science and Technology and Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
| | - Ira A. Weinstock
- Department of Chemistry, Unit of Environmental Engineering, and Ilse Katz Institute for Nanoscale Science and Technology and Department of Materials Engineering, Ben Gurion University of the Negev, Beer Sheva, 84105, Israel
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191
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Fox JD, Rowan SJ. Supramolecular Polymerizations and Main-Chain Supramolecular Polymers. Macromolecules 2009. [DOI: 10.1021/ma901144t] [Citation(s) in RCA: 293] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Justin D. Fox
- Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Road, Cleveland, Ohio 44106-7202
| | - Stuart J. Rowan
- Department of Macromolecular Science and Engineering, Case Western Reserve University, 2100 Adelbert Road, Cleveland, Ohio 44106-7202
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192
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Minyaev RM, Starikov AG, Minkin VI. Novel structural motif for stabilization of polyacene systems. DOKLADY PHYSICAL CHEMISTRY 2009. [DOI: 10.1134/s0012501609040034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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193
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Wan J, Thomas MS, Guthrie S, Vullev VI. Surface-bound proteins with preserved functionality. Ann Biomed Eng 2009; 37:1190-205. [PMID: 19308733 DOI: 10.1007/s10439-009-9673-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Accepted: 03/09/2009] [Indexed: 12/28/2022]
Abstract
Biocompatibility of materials strongly depends on their surface properties. Therefore, surface derivatization in a controllable manner provides means for achieving interfaces essential for a broad range of chemical, biological, and medical applications. Bioactive interfaces, while manifesting the activity for which they are designed, should suppress all nonspecific interaction between the supporting substrates and the surrounding media. This article describes a procedure for chemical derivatization of glass and silicon surfaces with polyethylene glycol (PEG) layers covalently functionalized with proteins. While the proteins introduce the functionality to the surfaces, the PEGs provide resistance against nonspecific interactions. For formation of aldehyde-functionalized surfaces, we coated the substrates with acetals (i.e., protected aldehydes). To avoid deterioration of the surfaces, we did not use strong mineral acids for the deprotection of the aldehydes. Instead, we used a relatively weak Lewis acid for conversion of the acetals into aldehydes. Introduction of alpha,omega-bifunctional polymers into the PEG layers, bound to the aldehydes, allowed us to covalently attach green fluorescent protein and bovine carbonic anhydrase to the surfaces. Spectroscopic studies indicated that the surface-bound proteins preserve their functionalities. The surface concentrations of the proteins, however, did not manifest linear proportionality to the molar fractions of the bifunctional PEGs used for the coatings. This finding suggests that surface-loading ratios cannot be directly predicted from the compositions of the solutions of competing reagents used for chemical derivatization.
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Affiliation(s)
- Jiandi Wan
- Department of Bioengineering, University of California, Riverside, A-220 Bourns Hall, Riverside, CA 92521, USA
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194
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Tong W, Wei Y, Armbrust KW, Zimmt MB. Dipolar side chain control of monolayer morphology: symmetrically substituted 1,5-(mono- and diether) anthracenes at the solution-HOPG interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:2913-2923. [PMID: 19239193 DOI: 10.1021/la803811w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Scanning tunneling microscopy (STM) is used to determine the 2-D unit cell parameters of monolayers self-assembled by twelve symmetrical, 1,5-bis(linear aliphatic ether side chain) anthracenes at the solution-graphite interface. The standard morphology assembled by 1,5-bis(alkyloxymethyl) anthracenes consists of single-lamella domains containing columns of anthracene cores alternating with columns of interdigitated, aliphatic side chains. Adjacent side chains within the aliphatic columns adsorb in antiparallel orientations. The terminal methyl (omega-position) of each side chain lies in registration with the 2-positions of its two neighboring chains ((omega <--> 2)-packing). Anthracenes with diether side chains can generate repulsive or attractive dipole-dipole interactions between proximate ethers of adjacent aliphatic chains. Anthracenes bearing even length side chains with oxygens at the 2- and omega-1 positions or at the 3- and omega-2 positions do not assemble (omega <--> 2)-packed monolayers. Repulsive dipolar interactions between ethers in adjacent side chains raise the energy of (omega <--> 2) morphologies. These "self-repulsive" side chains drive assembly of (omega <--> l)- or (omega <--> 3)-packed morphologies, which enjoy stabilizing dipolar interactions between ethers in adjacent side chains. In stark contrast, anthracenes bearing odd length diether side chains assemble (omega <--> 2)-packed morphologies, regardless of whether adjacent chains suffer zero, one, or two sets of proximate dipole-dipole repulsions. The intrinsic energy gap from (omega <--> 2)- to non-(omega <--> 2)-packed morphologies of odd length side chain anthracenes is, apparently, larger than for even length side chain anthracenes. Overall, the twelve compounds self-assemble seven different morphologies. Distinguishing morphologies, understanding polymorphism within the monolayers, and evaluating the morphological consequences of side chain dipolar interactions is facilitated by viewing the monolayers as assemblies of 1-D, molecular tapes.
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Affiliation(s)
- Wenjun Tong
- Department of Chemistry, Brown University Providence, Rhode Island 02912, USA
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195
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Béthencourt MI, Srisombat LO, Chinwangso P, Lee TR. SAMs on gold derived from the direct adsorption of alkanethioacetates are inferior to those derived from the direct adsorption of alkanethiols. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:1265-1271. [PMID: 19123812 DOI: 10.1021/la803179q] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Self-assembled monolayers (SAMs) on gold derived from the direct adsorption of thioacetic acid S-decyl ester (C10SAc) and thioacetic acid S-octadecyl ester (C18SAc) were compared to the corresponding SAMs derived from the analogous adsorption n-decanethiol (C10SH) and n-octadecanethiol (C18SH). All SAMs were characterized using ellipsometry, contact angle goniometry, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS). The comparison revealed that the SAMs generated from the thioacetates are not as densely packed and well ordered as the SAMs generated from the thiols. Furthermore, studies of the kinetics of adsorption found that the thioacetates adsorb more slowly than the corresponding thiols.
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Affiliation(s)
- Mathilde I Béthencourt
- Department of Chemistry, University of Houston, 4800 Calhoun Rd, Houston, Texas 77204-5003, USA
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196
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Kumar AMS, Fox JD, Buerkle LE, Marchant RE, Rowan SJ. Effect of monomer structure and solvent on the growth of supramolecular nanoassemblies on a graphite surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:653-6. [PMID: 19086887 PMCID: PMC2635022 DOI: 10.1021/la803369j] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The self-assembly of high aspect ratio hierarchical surface assemblies, as observed by fluid tapping mode AFM, can be achieved through careful design of the supramolecular interactions between low-molecular-weight adsorbates. Needlelike assemblies of monotopic guanine end-capped alkanes grow on a graphite surface when deposited from a water/DMSO solution. The growth of these assemblies can be monitored by AFM in real time, and the growth rate along the two different axes can be understood (through molecular modeling) in terms of the specific adsorbate-adsorbate interactions along those axes. Additionally, through judicious solvent selection (e.g., use of non-H-bonding solvents such as o-dichlorobenzene), which allows the formation of hydrogen-bonding aggregates in solution and influences the surface-adsorbate interactions, dramatically different surface assemblies of these guanine derivatives are obtained.
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Affiliation(s)
- Aryavarta M. S. Kumar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Justin D. Fox
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Lauren E. Buerkle
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Roger E. Marchant
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Stuart J. Rowan
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH 44106
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106
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197
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Dai J, Li Z, Jin J, Shi Y, Cheng J, Kong J, Bi S. Some thoughts on the existence of ion and water channels in highly dense and well-ordered CH3-terminated alkanethiol self-assembled monolayers on gold. Biosens Bioelectron 2009; 24:1074-82. [DOI: 10.1016/j.bios.2008.08.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 07/30/2008] [Accepted: 08/15/2008] [Indexed: 11/27/2022]
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198
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Katash I, Luo X, Sukenik CN. In situ sulfonation of alkyl benzene self-assembled monolayers: product distribution and kinetic analysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:10910-10919. [PMID: 18785720 DOI: 10.1021/la800746k] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The sulfonation of aromatic rings held at the surface of a covalently anchored self-assembled monolayer has been analyzed in terms of the rates and isomer distribution of the sulfonation process. The observed product distributions are similar to those observed in solution, though the data obtained suggest that the reaction rate and the ortho/para product ratio depend on the length of the tether anchoring the aryl ring to the monolayer interface. It was also found that the interface becomes progressively more disordered and the observed reaction rates decrease as the reaction progresses. There is no evidence for a bias in favor of reaction at the more exposed para-position nor is there evidence for an enhanced reaction rate due to the increased disorder and/or improved wetting as the reaction proceeds. This is the first detailed study of electrophilic aromatic substitution at a monolayer interface. It introduces new approaches to the spectroscopic analysis of reactions on self-assembled monolayers and provides a new general approach to the analysis of isomeric product distribution in such a setting.
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Affiliation(s)
- Irit Katash
- Department of Chemistry, Bar Ilan University, Ramat Gan, Israel
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199
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Yuan M, Zhan S, Zhou X, Liu Y, Feng L, Lin Y, Zhang Z, Hu J. A method for removing self-assembled monolayers on gold. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:8707-10. [PMID: 18582131 DOI: 10.1021/la800287e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Self-assembled monolayers (SAMs) have been widely used in studying interfacial phenomena, biological processes, electrochemistry, photoelectrochemistry, photoactivity and molecular interaction. Much research has been carried out in fabricating and removing SAMs on different substrates. In this work, we report for the first time, to our knowledge, that SAMs of thiolates on gold can be removed by immersing SAMs in 0.5 M NaBH 4 solution for 10 min. The procedure of removing thiolates was very convenient. Cyclic voltammetry, surface-enhanced Raman spectroscopy, and X-ray photoelectron spectroscopy were used to characterize this process. The results indicated that the SAMs of thiolates on gold can be removed efficiently by NaBH 4.
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Affiliation(s)
- Mingquan Yuan
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, People's Republic of China
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200
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Tao F, Tang D, Salmeron M, Somorjai GA. A new scanning tunneling microscope reactor used for high-pressure and high-temperature catalysis studies. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:084101. [PMID: 19044362 DOI: 10.1063/1.2960569] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present the design and performance of a homebuilt high-pressure and high-temperature reactor equipped with a high-resolution scanning tunneling microscope (STM) for catalytic studies. In this design, the STM body, sample, and tip are placed in a small high pressure reactor ( approximately 19 cm(3)) located within an ultrahigh vacuum (UHV) chamber. A sealable port on the wall of the reactor separates the high pressure environment in the reactor from the vacuum environment of the STM chamber and permits sample transfer and tip change in UHV. A combination of a sample transfer arm, wobble stick, and sample load-lock system allows fast transfer of samples and tips between the preparation chamber, high pressure reactor, and ambient environment. This STM reactor can work as a batch or flowing reactor at a pressure range of 10(-13) to several bars and a temperature range of 300-700 K. Experiments performed on two samples both in vacuum and in high pressure conditions demonstrate the capability of in situ investigations of heterogeneous catalysis and surface chemistry at atomic resolution at a wide pressure range from UHV to a pressure higher than 1 atm.
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Affiliation(s)
- Feng Tao
- Materials Science and Chemistry Divisions, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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