1
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Smith RJ, Gorman C, Menegatti S. Synthesis, structure, and function of internally functionalized dendrimers. JOURNAL OF POLYMER SCIENCE 2020. [DOI: 10.1002/pol.20200721] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Ryan J. Smith
- Department of Chemistry North Carolina State University Raleigh North Carolina USA
| | - Christopher Gorman
- Department of Chemistry North Carolina State University Raleigh North Carolina USA
| | - Stefano Menegatti
- Department of Chemical and Biomolecular Engineering North Carolina State University Raleigh North Carolina USA
- Biomanufacturing Training and Education Center Raleigh North Carolina USA
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2
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Ohta S, Ohki Y. Impact of ligands and media on the structure and properties of biological and biomimetic iron-sulfur clusters. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.02.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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3
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Liu G, Li Z, Wu D, Xue W, Li T, Liu SH, Yin J. Dendritic [2]Rotaxanes: Synthesis, Characterization, and Properties. J Org Chem 2014; 79:643-52. [DOI: 10.1021/jo402428y] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Guoxing Liu
- Key
Laboratory of Pesticide and Chemical Biology, Ministry of Education,
College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Ziyong Li
- Key
Laboratory of Pesticide and Chemical Biology, Ministry of Education,
College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Di Wu
- Key
Laboratory of Pesticide and Chemical Biology, Ministry of Education,
College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Wen Xue
- Key
Laboratory of Pesticide and Chemical Biology, Ministry of Education,
College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Tingting Li
- Institute
of Hydrobiology, Chinese Academy of Sciences, Wuhan 430079, P.R. China
| | - Sheng Hua Liu
- Key
Laboratory of Pesticide and Chemical Biology, Ministry of Education,
College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
| | - Jun Yin
- Key
Laboratory of Pesticide and Chemical Biology, Ministry of Education,
College of Chemistry, Central China Normal University, Wuhan 430079, P.R. China
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4
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Xu L, Chen LJ, Yang HB. Recent progress in the construction of cavity-cored supramolecular metallodendrimers via coordination-driven self-assembly. Chem Commun (Camb) 2014; 50:5156-70. [DOI: 10.1039/c3cc47484d] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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5
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Xu XD, Ou-Yang JK, Zhang J, Zhang YY, Gong HY, Yu Y, Yang HB. Self-assembly of supramolecular tris(crown ether) hexagons with dendritic dibenzylammonium cations. Tetrahedron 2013. [DOI: 10.1016/j.tet.2012.11.065] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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6
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Han Q, Li QJ, He J, Hu B, Tan H, Abliz Z, Wang CH, Yu Y, Yang HB. Design and Synthesis of 60° Dendritic Donor Ligands and Their Coordination-Driven Self-Assembly into Supramolecular Rhomboidal Metallodendrimers. J Org Chem 2011; 76:9660-9. [DOI: 10.1021/jo201594u] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Qing Han
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes,
Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, P. R. China
| | - Quan-Jie Li
- Department of Chemistry, Beijing Normal University, Beijing 100050, P. R. China
| | - Jiuming He
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R.
China
| | - Bingjie Hu
- Shanghai Key Laboratory
of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Hongwei Tan
- Department of Chemistry, Beijing Normal University, Beijing 100050, P. R. China
| | - Zeper Abliz
- Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, P. R.
China
| | - Cui-Hong Wang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes,
Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, P. R. China
| | - Yihua Yu
- Shanghai Key Laboratory
of Magnetic Resonance, Department of Physics, East China Normal University, Shanghai 200062, P. R. China
| | - Hai-Bo Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes,
Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai 200062, P. R. China
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7
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Synthesis, characterization, and properties of binuclear ruthenium complexes with dendritic side chains on their bridges. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.01.075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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8
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Zhao GZ, Chen LJ, Wang CH, Yang HB, Ghosh K, Zheng YR, Lyndon MM, Muddiman DC, Stang PJ. Facile Self-Assembly of Dendritic Multiferrocenyl Hexagons and Their Electrochemistry. Organometallics 2010. [DOI: 10.1021/om1008605] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Guang-Zhen Zhao
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai, People's Republic of China, 200062
| | - Li-Jun Chen
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai, People's Republic of China, 200062
| | - Cui-Hong Wang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai, People's Republic of China, 200062
| | - Hai-Bo Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 N. Zhongshan Road, Shanghai, People's Republic of China, 200062
| | - Koushik Ghosh
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Yao-Rong Zheng
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
| | - Matthew M. Lyndon
- W. M. Keck FT-ICR Mass Spectrometry Laboratory and Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - David C. Muddiman
- W. M. Keck FT-ICR Mass Spectrometry Laboratory and Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Peter J. Stang
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, United States
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9
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Sharma AK, Kim N, Cameron CS, Lyndon M, Gorman CB. Dendritically encapsulated, water-soluble fe(4)s(4): synthesis and electrochemical properties. Inorg Chem 2010; 49:5072-8. [PMID: 20450203 DOI: 10.1021/ic1002447] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Amphiphilic, Fe(4)S(4) cluster core dendrimers can be prepared via ligand exchange with dendrons containing carboxylic acid peripheral groups and a thiol focal group. These amphiphilic dendrons are more susceptible to oxidative disulfide formation than their non-amphiphilic analogues reported previously. Thus, an in situ deprotection of an aromatic thioacetate was necessary to prepare the dendrimers. These molecules showed the expected decrease in rate with increasing generation. A slower rate of heterogeneous electron transfer was found when these molecules were compared with non-amphiphilic analogues. This behavior correlated with their larger size and thus a larger effective distance of electron transfer. Voltammetry in DMSO with added water makes the dendrimers easier to reduce, but the change in redox potential is much smaller for all dendrimers when compared to a non-dendritic analogue. This behavior is consistent with the idea that the dendrimers encapsulate the cluster to some degree, creating a hydrophobic microenvironment around the cluster.
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Affiliation(s)
- Anil K Sharma
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 28795-8204, USA
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10
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Yang HB, Northrop BH, Zheng YR, Ghosh K, Lyndon MM, Muddiman DC, Stang PJ. Synthesis of six-component metallodendrimers via [3 + 3] coordination-driven self-assembly. J Org Chem 2009; 74:3524-7. [PMID: 19344131 DOI: 10.1021/jo900067v] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new class of 120 degrees dendritic di-Pt(II) acceptor subunits has been designed and synthesized, from which six-component hexagonal metallodendrimers were easily formed with 120 degrees dendritic dipyridine donors via [3 + 3] coordination-driven self-assembly. The structures of all metallodendrimers are confirmed by multinuclear NMR, ESI-TOF-MS/ESI-FTMS, and elemental analysis. MMFF force-field simulations indicates that all metallodendrimers have a hexagonal ring with an internal radius of approximately 1.4 nm.
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Affiliation(s)
- Hai-Bo Yang
- Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University, 3663 North Zhongshan Road, Shanghai, China 200062.
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11
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Zhang W, Lalwani S, Chouai A, Simanek EE. Synthesis and Characterization of Anionic Triazine Dendrimers with a Labile Disulfide Core. Isr J Chem 2009; 49:23-30. [PMID: 19936277 PMCID: PMC2780346 DOI: 10.1560/ijc.49.1.23] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Anionic dendrimers based on melamine with disulfide bonds at the core were prepared to investigate the solubility of these architectures, the ability of these molecules to solubilize pyrene as a model drug, and the ability of these architectures to undergo thiol-disulfide exchange. The ability to solubilize pyrene is directly correlated with molecular weight of the dendrimer-aggregation of dendrons does not occur. Thiol-disulfide exchange occurs rapidly using dithiothreitol as the reductant to yield dendrimers with thiol cores that can undergo oxidation in air to yield the original dendrimer.
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Affiliation(s)
- Wen Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Sanjiv Lalwani
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Abdellatif Chouai
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - Eric E. Simanek
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
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12
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Gingras M, Placide V, Raimundo JM, Bergamini G, Ceroni P, Balzani V. Polysulfurated Pyrene-Cored Dendrimers: Luminescent and Electrochromic Properties. Chemistry 2008; 14:10357-63. [DOI: 10.1002/chem.200801198] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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13
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Yang HB, Das N, Huang F, Hawkridge AM, Muddiman DC, Stang PJ. Molecular architecture via coordination: self-assembly of nanoscale hexagonal metallodendrimers with designed building blocks. J Am Chem Soc 2007; 128:10014-5. [PMID: 16881621 DOI: 10.1021/ja063377z] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The first self-assembly of nanoscale metallodendrimers that have a hexagonal cavity as a core via the directional-bonding approach is reported. All metallodendrimers were characterized by multinuclear NMR (1H and 31P), mass spectrometry (ESI-MS and ESI-FT-ICR), and elemental analysis.
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Affiliation(s)
- Hai-Bo Yang
- Department of Chemistry, University of Utah, 315 South 1400 East, RM 2020, Salt Lake City, Utah 84112, USA
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14
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Design, Syntheses, and Characterization of a Sterically Encumbered Dioxo Molybdenum (VI) Core. Inorganica Chim Acta 2007; 360:2092-2099. [PMID: 18425212 DOI: 10.1016/j.ica.2006.10.041] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dioxo-Mo(VI) complexes of general formula Tp*MoO(2)(p-SC(6)H(4)Dn) (6a-6c) (where Tp* = hydrotris(3,5-dimethyl-pyrazol-1-yl)borate and Dn= dendritic unit) have been synthesized and characterized by spectroscopy and mass spectrometry. (1)H NMR spectra of the metal complexes indicate that the C(s) local symmetry about the metal core does not change by the incorporation of dendritic functionality at the thiophenolato ring. Electrochemical data show ∼20 mV change in the redox potential in the complexes with dendritic ligands suggesting a very small perturbation in the redox orbital, which is also supported by small changes in the electronic spectra. The peak-to peak separation (ΔE(p)) increases from 125 mV in 6(a) to 240 mV in 6(c), suggesting sluggish electron transfer in molecules with larger dendritic ligands.
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15
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Yang HB, Hawkridge AM, Huang SD, Das N, Bunge SD, Muddiman DC, Stang PJ. Coordination-driven self-assembly of metallodendrimers possessing well-defined and controllable cavities as cores. J Am Chem Soc 2007; 129:2120-9. [PMID: 17256935 DOI: 10.1021/ja066804h] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The design and self-assembly of novel cavity-cored metallodendrimers via noncovalent interactions are described. By employing [G0]-[G3] 120 degrees ditopic donor linkers substituted with Fréchet-type dendrons and appropriate rigid di-Pt(II) acceptor subunits, [G0]-[G3]-rhomboidal metallodendrimers and [G0]-[G3]-hexagonal, "snowflake-shaped" metallodendrimers with well-defined shape and size were prepared under mild conditions in high yields. The assemblies were characterized with multinuclear NMR ((1)H and (31)P), mass spectrometry (ESI-MS and ESI-FT-ICR-MS), and elemental analysis. Isotopically resolved mass spectrometry data support the existence of the metallodendrimers with rhomboidal and hexagonal cavities, and NMR data are consistent with the formation of all ensembles. The structures of [G0]- and [G1]-rhomboidal metallodendrimers were unambiguously confirmed via single-crystal X-ray crystallography. The shape and size of two [G3]-hexagonal metallodendrimers were investigated with MM2 force-field modeling.
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Affiliation(s)
- Hai-Bo Yang
- Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, USA.
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16
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Hahn U, Cardinali F, Nierengarten JF. Supramolecular chemistry for the self-assembly of fullerene-rich dendrimers. NEW J CHEM 2007. [DOI: 10.1039/b612873b] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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McNaughton RL, Mondal S, Nemykin VN, Basu P, Kirk ML. Oxomolybdenum tetrathiolates with sterically encumbering ligands: modeling the effect of a protein matrix on electronic structure and reduction potentials. Inorg Chem 2006; 44:8216-22. [PMID: 16270958 DOI: 10.1021/ic0482281] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The effect of sterically encumbering ligands on the electronic structure of oxomolybdenum tetrathiolate complexes was determined using a combination of electronic absorption and magnetic circular dichroism spectroscopies, complimented by DFT bonding calculations, to understand geometric and electronic structure contributions to reduction potentials. These complexes are rudimentary models for a redox-active metalloenzyme active site in a protein matrix and allow for detailed spectroscopic probing of specific oxomolybdenum-thiolate interactions that are directly relevant to Mo-S(cysteine) bonding in pyranopterin molybdenum enzymes. Data are presented for three para-substituted oxomolybdenum tetrathiolate complexes ([PPh4][MoO(p-SPhCONHCH3)4], [PPh4][MoO(p-SPhCONHC(CH2O(CH2)2CN)3)4], and [PPh4][MoO(p-SPhCONHC(CH2O(CH2)2COOCH2CH3)3)4]). The Mo(V/IV) reduction potentials of the complexes in DMF are -1213, -1251, and -1247 mV, respectively. The remarkably similar electronic absorption and magnetic circular dichroism spectra of these complexes establish that the observed reduction potential differences are not a result of significant changes in the electronic structure of the [MoOS4]- cores as a function of the larger ligand size. We provide evidence that these reduction potential differences result from the driving force for a substantial reorganization of the O-Mo-S-C dihedral angle upon reduction, which decreases electron donation from the thiolate sulfurs to the reduced molybdenum center. The energy barrier to favorable O-Mo-S-C geometries results in a reorganizational energy increase, relative to [MoO(SPh)4](-/2-), that correlates with ligand size. The inherent flexible nature of oxomolybdenum-thiolate bonds indicate that thiolate ligand geometry, which controls Mo-S covalency, could affect the redox processes of monooxomolybdenum centers in pyranopterin molybdenum enzymes.
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Affiliation(s)
- Rebecca L McNaughton
- Department of Chemistry, The University of New Mexico, MSC03 2060, 1 University of New Mexico, Albuquerque, New Mexico 87131-0001, USA
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18
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Shon YS, Choi D. A Route to Redox-active Nanoparticle-cored Dendrimers: Post-encapsulation of Ferrocene. CHEM LETT 2006. [DOI: 10.1246/cl.2006.644] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Yamamoto K, Imaoka T. Dendrimer Complexes Based on Fine-Controlled Metal Assembling. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2006. [DOI: 10.1246/bcsj.79.511] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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20
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Chen J, Chen J, Li S, Zhang L, Yang G, Li Y. Conversion of Intramolecular Singlet Electron Transfer at Room Temperature into Triplet Energy Transfer at 77 K: Photoisomerization in Norbornadiene- and Carbazole-Labeled Poly(aryl ether) Dendrimers. J Phys Chem B 2006; 110:4663-70. [PMID: 16526699 DOI: 10.1021/jp057002w] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of Fréchet-type poly(aryl ether) dendrimers (CZ-Gn-NBD, n = 1-3) with carbazole (CZ) chromophores and a norbornadiene (NBD) group attached to the periphery and the core, respectively, were synthesized, and their photophysical and photochemical properties were investigated. Selective excitation of the carbazole units in CZ-Gn-NBD resulted in a singlet electron transfer from CZ to NBD at room temperature, and an intersystem crossing followed a triplet-triplet energy transfer from CZ to NBD in glassy 2-methyltetrahydrofuran at 77 K. Both singlet electron transfer and triplet energy transfer processes lead to the isomerization of the norbornadiene group into the quadricyclane (CZ-Gn-QC). The efficiencies and the rate constants for singlet electron transfer are approximately 88, 80, and 74% and 1.8 x 10(9), 6.1 x 10(8), and 4.0 x 10(8) s(-1) for generations 1-3, respectively. The quantum yields of the intramolecular photosensitized isomerization are measured to be approximately 0.013, 0.012, and 0.011, and the efficiencies of triplet norbornadiene formation via singlet electron transfer are approximately 0.070, 0.065, and 0.059 for generations 1-3, respectively. The light-harvesting ability of CZ-Gn-NBD increases with the generation due to an increase of the number of peripheral chromophores. In glassy 2-methyltetrahydrofuran at 77 K, the triplet-triplet energy transfer proceeds with efficiencies of approximately 0.86, 0.64, and 0.36 and rate constants of 0.96, 0.25, and 0.08 s(-1) for generations 1-3, respectively. The intramolecular singlet electron transfer and triplet energy transfer in CZ-Gn-NBD proceed mainly via a through-space mechanism involving the proximate donor (folding back conformation) and acceptor groups.
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Affiliation(s)
- Jie Chen
- Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100101, China
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21
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Smith DK, Hirst AR, Love CS, Hardy JG, Brignell SV, Huang B. Self-assembly using dendritic building blocks—towards controllable nanomaterials. Prog Polym Sci 2005. [DOI: 10.1016/j.progpolymsci.2005.01.006] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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Chasse TL, Gorman CB. Effect of structure on the reduction potentials of films of constitutional isomers of iron-sulfur cluster core dendrimers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:8792-8795. [PMID: 15379508 DOI: 10.1021/la048733a] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The thermodynamic redox potentials of films of constitutional isomers of iron-sulfur cluster core dendrimers were measured and compared. It was determined that the primary structure of the dendrimer influences its reduction potential. Dendrimers containing so-called backfolded linkages were more difficult to reduce than their extended analogues. This behavior is rationalized by suggesting that the backfolded isomers pack more tightly around the iron-sulfur cluster, creating a more hydrophobic local microenvironment. Also, all of these molecules are easier to reduce in the film than in dimethyl formamide solution. The variation in redox potential between film and solution environment was compared to that of dendrimers of differing generations and correlated with the amount of hydrophobic dendron surrounding the cluster.
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Affiliation(s)
- Tyson L Chasse
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh 27695-8204, USA
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23
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Chasse TL, Smith JC, Carroll RL, Gorman CB. Effect of the counterion on the rate of electron transfer in dendrimer films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:3501-3. [PMID: 15875372 DOI: 10.1021/la049818e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The electrochemical behavior of a film composed of a redox-active dendrimer was studied as a function of the type of counterion available during its reduction and reoxidation. The rate of permeation/migration of counterions into the film appeared to be the bottleneck to electron transfer through the film. Because the dendrimer is rather hydrophobic, increasing the hydrophobicity of the counterion increased the rate and extent of electron hopping within the films.
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Affiliation(s)
- Tyson L Chasse
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, USA
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24
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Gillies ER, Fréchet JMJ. Synthesis and Self-Assembly of Supramolecular Dendritic “Bow-Ties”: Effect of Peripheral Functionality on Association Constants. J Org Chem 2003; 69:46-53. [PMID: 14703377 DOI: 10.1021/jo035329s] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Self-assembled polyester dendritic bow-ties with various peripheral groups were prepared, and their association constants were measured by (1)H NMR in CDCl(3). The two complementary dendrons were prepared by attachment of either a bis(adamantylurea) or a glycinylurea to the focal point of the dendron. The parent self-assembled system with benzylidene acetals on one periphery and isopropylidene acetals on the other had an association constant of 520 M(-)(1). Upon deprotection of one dendron, the association constant is increased by more than an order of magnitude as the solubility of the hydroxyl-terminated dendron in CDCl(3) is decreased. In contrast, attachment of tri(ethylene oxide) units to the periphery of one dendron lowers the association constant by almost an order of magnitude. The causes of these relatively large changes in complex strength are discussed in terms of solubility, steric effects, competitive hydrogen bonding, and the structure of the dendritic scaffold.
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Affiliation(s)
- Elizabeth R Gillies
- Center for New Directions in Organic Synthesis, Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
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25
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Hong YR, Gorman CB. Synthetic Approaches to an Isostructural Series of Redox-Active, Metal Tris(bipyridine) Core Dendrimers. J Org Chem 2003; 68:9019-25. [PMID: 14604376 DOI: 10.1021/jo0351116] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Several types of six-armed, metal tris(bipyridine) core dendrimers were synthesized. Bis-4,4'-alkoxy bipyridine dendrons were prepared and employed to make tris(bipyridine) dendrimers. Although the ruthenium-centered and iron-centered dendrimers displayed quasi-reversible cyclic voltammetry, the analogous cobalt-centered complex did not. The synthesis of 4,4'-disubstituted bipyridines containing -CH(2)OR groups proceeded in low yield. The reactions of the dicarbanion of 4,4'-dimethyl bipyridine prepared with LDA and mesylate, triflate, and bromide groups were found to result in no or poor yields of carbon-carbon bond formation. Use of KDA in place of LDA resulted in much higher yields of dendritic bipyridines.
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Affiliation(s)
- Young-Rae Hong
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, NC 27695-8204, USA
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Chasse TL, Sachdeva R, Li Q, Li Z, Petrie RJ, Gorman CB. Structural effects on encapsulation as probed in redox-active core dendrimer isomers. J Am Chem Soc 2003; 125:8250-4. [PMID: 12837096 DOI: 10.1021/ja035515f] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Three pairs of isomeric, iron-sulfur core dendrimers were prepared. Each isomer pair was distinguished by a 3,5-aromatic substitution pattern (extended) versus 2,6-aromatic substitution pattern (backfolded). Several observations were made that supported the hypothesis that the iron-sulfur cluster cores were encapsulated more effectively in the backfolded isomers as compared to their extended isomeric counterparts. The backfolded isomers were more difficult to reduce electrochemically, consistent with encapsulation in a more hydrophobic microenvironment. Furthermore, heterogeneous electron-transfer rates for the backfolded molecules were attenuated compared to the extended molecules. From diffusion measurements obtained by pulsed field gradient spin-echo NMR and chronoamperometry, the backfolded dendrimers were found to be smaller than the extended dendrimers. Comparison of longitudinal proton relaxation (T(1)) values also indicated a smaller, more compact dendrimer conformation for the backfolded architectures. These findings indicated that the dendrimer size was not the major factor in determining electron-transfer rate attenuation. Instead, the effective electron-transfer distance, as determined by the relative core position and mobility in a dendrimer, is most relevant for encapsulation.
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Affiliation(s)
- Tyson L Chasse
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, NC 27695-8204, USA
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Leashed ferrocenes at clay surfaces: potential applications for environmental catalysis. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s1381-1169(03)00031-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Chasse TL, Yohannan JC, Kim N, Li Q, Li Z, Gorman CB. Dendritic encapsulation-roles of cores and branches. Tetrahedron 2003. [DOI: 10.1016/s0040-4020(03)00435-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Stone DL, Smith DK, McGrail PT. Ferrocene encapsulated within symmetric dendrimers: a deeper understanding of dendritic effects on redox potential. J Am Chem Soc 2002; 124:856-64. [PMID: 11817961 DOI: 10.1021/ja0117478] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ferrocene has been encapsulated within a symmetric ether-amide dendritic shell and its redox potential monitored in a variety of solvents. The dendritic effect generated by the branched shell is different in different solvents. In less polar, non hydrogen bond donor solvents, attachment of the branched shell to ferrocene increases its E(1/2), indicating that oxidation to ferrocenium (charge buildup) becomes thermodynamically hindered by the dendrimer, a result explained by the dendrimer providing a less polar medium than that of the surrounding electrolyte solution. The effect of electrolyte concentration on redox potential was also investigated, and it was shown that the concentration of "innocent" electrolyte has a significant effect on the redox potential by increasing the overall polarity of the surrounding medium. Dendritic destabilization of charge buildup is in agreement with the majority of reported dendritic effects. A notable exception to this is provided by the asymmetric ferrocene dendrimers previously reported by Kaifer and co-workers, in which the branching facilitated oxidation, and it is proposed that in this case the dendritic effect is generated by a different mechanism. Interestingly, in methanol, the new symmetric ferrocene dendrimer exhibited almost no dendritic effect, a result explained by the ability of methanol to interact extensively with the branched shell, generating a more open superstructure. By comparison of all the new data with other reports, this study provides a key insight into the structure-activity relationships which control redox processes in dendrimers and also an insight into the electrochemical process itself.
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Affiliation(s)
- Diane L Stone
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
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Grayson SM, Fréchet JM. Convergent dendrons and dendrimers: from synthesis to applications. Chem Rev 2001; 101:3819-68. [PMID: 11740922 DOI: 10.1021/cr990116h] [Citation(s) in RCA: 1173] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S M Grayson
- Department of Chemistry, University of California, Berkeley, California 94720-1460, USA
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Liwporncharoenvong T, Luck RL. Quadruply bonded dimolybdenum atoms surrounded by dendrons: preparation, characterization, and electrochemistry. J Am Chem Soc 2001; 123:3615-6. [PMID: 11472142 DOI: 10.1021/ja0155130] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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