51
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Xu CH, Sun W, Zheng YR, Fang CJ, Zhou C, Jin JY, Yan CH. Logic circuits constructed with an ion-sensitive fluorescent molecule 1,2-di[5-methoxy-2-(2-pyridyl)thiazoyl]ethyne. NEW J CHEM 2009. [DOI: 10.1039/b817098c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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52
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de Silva AP, Dobbin CM, Vance TP, Wannalerse B. Multiply reconfigurable ‘plug and play’ molecular logic via self-assembly. Chem Commun (Camb) 2009:1386-8. [DOI: 10.1039/b822181b] [Citation(s) in RCA: 46] [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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53
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Kumar S, Luxami V, Saini R, Kaur D. Superimposed molecular keypad lock and half-subtractor implications in a single fluorophore. Chem Commun (Camb) 2009:3044-6. [DOI: 10.1039/b900131j] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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54
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Qian J, Xu Y, Qian X, Zhang S. Molecular Logic Operations Based on Surfactant Nanoaggregates. Chemphyschem 2008; 9:1891-8. [DOI: 10.1002/cphc.200800009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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55
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Zhang D, Su J, Ma X, Tian H. An efficient multiple-mode molecular logic system for pH, solvent polarity, and Hg2+ ions. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.05.048] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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56
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Affiliation(s)
- Konrad Szaciłowski
- Uniwersytet Jagielloński, Wydział Chemii, ul. Romana Ingardena 3, 30-060 Kraków, Poland
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57
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Pischel U, Heller B. Molecular logic devices (half-subtractor, comparator, complementary output circuit) by controlling photoinduced charge transfer processes. NEW J CHEM 2008. [DOI: 10.1039/b710216j] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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58
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Qian J, Qian X, Xu Y, Zhang S. Multiple molecular logic functions and molecular calculations facilitated by surfactant’s versatility. Chem Commun (Camb) 2008:4141-3. [DOI: 10.1039/b805876h] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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59
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Suresh M, Ghosh A, Das A. A simple chemosensor for Hg2+ and Cu2+ that works as a molecular keypad lock. Chem Commun (Camb) 2008:3906-8. [DOI: 10.1039/b807290f] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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60
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Luxami V, Kumar S. Molecular half-subtractor based on 3,3′-bis(1H-benzimidazolyl-2-yl)[1,1′]binaphthalenyl-2,2′-diol. NEW J CHEM 2008. [DOI: 10.1039/b805558k] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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61
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Rurack K, Trieflinger C, Koval'chuck A, Daub J. An Ionically Driven Molecular IMPLICATION Gate Operating in Fluorescence Mode. Chemistry 2007; 13:8998-9003. [PMID: 17705328 DOI: 10.1002/chem.200700858] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
An asymmetrically core-extended boron-dipyrromethene (BDP) dye was equipped with two electron-donating macrocyclic binding units with different metal ion preferences to operate as an ionically driven molecular IMPLICATION gate. A Na(+)-responsive tetraoxa-aza crown ether (R(2)) was integrated into the extended pi system of the BDP chromophore to trigger strong intramolecular charge transfer (ICT(2)) fluorescence and guarantee cation-induced spectral shifts in absorption. A dithia-oxa-aza crown (R(1)) that responds to Ag(+) was attached to the meso position of BDP in an electronically decoupled fashion to independently control a second ICT(1) process of a quenching nature. The bifunctional molecule is designed in such a way that in the absence of both inputs, ICT(1) does not compete with ICT(2) and a high fluorescence output is obtained (In(A)=In(B)=0-->Out=1). Accordingly, binding of only Ag(+) at R(1) (In(A)=1, In(B)=0) as well as complexation of both receptors (In(A)=In(B)=1) also yields Out=1. Only for the case in which Na(+) is bound at R(2) and R(1) is in its free state does quenching occur, which is the distinguishing characteristic for the In(A)=0 and In(B)=1-->Out=0 state that is required for a logic IMPLICATION gate and Boolean operations such as IF-THEN or NOT.
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Affiliation(s)
- Knut Rurack
- Div. I.5 Bioanalytik, Bundesanstalt für Materialforschung und -prüfung (BAM), Richard Willstätter Strasse 11, 12489 Berlin, Germany.
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62
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Suresh M, Ghosh A, Das A. Half-subtractor operation in pH responsive N-heterocyclic amines. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.09.085] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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63
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64
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Zong G, Xian L, Lu G. l-Arginine bearing an anthrylmethyl group: fluorescent molecular NAND logic gate with H+ and ATP as inputs. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.03.139] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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65
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Magri DC, Vance TP, de Silva AP. From complexation to computation: Recent progress in molecular logic. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2006.07.076] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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66
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Abstract
[structure/diagram: see text] Spectral responses at two different wavelengths revealed that BP(OH)2 ([2,2'-bipyridyl]-3,3'-diol) can function as a combinatorial logic circuit for a molecular half-subtractor with acid and base as input variables.
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Affiliation(s)
- Moorthy Suresh
- Central Salt and Marine Chemicals Research Institute (CSIR), Bhavnagar 364002, Gujarat, India
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67
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Najmabadi P, La Clair JJ, Burkart MD. A systems perspective to digital structures in molecular analysis. Org Biomol Chem 2007; 5:214-22. [PMID: 17205161 DOI: 10.1039/b614507h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Within the last decade, the advance of miniaturization has opened the window to new systems that permit digital and molecular science to intersect, suggesting a new role for organic chemistry. Currently, fusion of molecules and electronic digits, as well as molecular-based digital structures, have expanded the conventional interpretation of the digit. This emergence has already generated new technological platforms with unique applications for molecular analysis and computation. We provide a brief overview of the conventional understanding of digital devices, examine the concept of molecular-based digits, and suggest new architectures by examining studies conducted on the compact discs. This analysis presents a perspective for the unique interaction of molecules and digits and the development of digital-based platforms for molecular analysis.
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Affiliation(s)
- Peyman Najmabadi
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0358, USA
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68
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Margulies D, Felder CE, Melman G, Shanzer A. A Molecular Keypad Lock: A Photochemical Device Capable of Authorizing Password Entries. J Am Chem Soc 2006; 129:347-54. [PMID: 17212414 DOI: 10.1021/ja065317z] [Citation(s) in RCA: 273] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper describes a new concept in the way information can be protected at the molecular scale. By harnessing the principles of molecular Boolean logic, we have designed a molecular device that mimics the operation of an electronic keypad lock, e.g., a common security circuit used for numerous applications, in which access to an object or data is to be restricted to a limited number of persons. What distinguishes this lock from a simple molecular logic gate is the fact that its output signals are dependent not only on the proper combination of the inputs but also on the correct order by which these inputs are introduced. In other words, one needs to know the exact passwords that open this lock. The different password entries are coded by a combination of two chemical and one optical input signals, which can activate, separately, blue or green fluorescence output channels from pyrene or fluorescein fluorophores. The information in each channel is a single-bit light output signal that can be used to authorize a user, to verify authentication of a product, or to initiate a higher process. This development not only opens the way for a new class of molecular decision-making devices but also adds a new dimension of protection to existing defense technologies, such as cryptography and steganography, previously achieved with molecules.
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Affiliation(s)
- David Margulies
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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69
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Nishimura G, Ishizumi K, Shiraishi Y, Hirai T. A Triethylenetetramine Bearing Anthracene and Benzophenone as a Fluorescent Molecular Logic Gate with Either−Or Switchable Dual Logic Functions. J Phys Chem B 2006; 110:21596-602. [PMID: 17064114 DOI: 10.1021/jp064131j] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Fluorescence behaviors of a triethylenetetramine bearing anthracene (AN) and benzophenone (BP) fragments at the respective ends, L1, have been studied in water, where effects of pH (H+) and metal cations on the emission properties have been studied in detail. L1 behaves as a fluorescent molecular logic gate driven by H+ (Input1) and metal cations (Input2) as input chemicals. The most notable feature of L1 is that this molecule expresses the "either-or" switchable dual logic functions. Operation of L1 with Cu2+ as Input2 expresses the INHIBIT logic function, where a strong AN fluorescence appears only at pH 4 (with H+) without Cu2+ [Input1(1)-Input2(0)]. In contrast, operations of L1 with all other metal cations as Input2 express the TRANSFER logic function, where the presence of H+ allows strong AN fluorescence regardless of whether the metal cation exists or not [Input1(1)-Input2(0); Input1(1)-Input2(1)]. These emission switching behaviors of L1 are driven by the difference in the coordination stability between L1 and metal cations and the photoinduced intramolecular electron and energy transfer processes: (i) a pH-induced electron transfer from unprotonated nitrogen atoms of the polyamine chain to the photoexcited AN [ELT(N-->AN*)]; (ii) a pH- and metal coordination-induced electron transfer from the photoexcited AN to the ground-state BP [ELT(AN*-->BP)]; and (iii) a Cu2+ coordination-induced energy transfer from the photoexcited AN to Cu2+ [ENT(AN*-->Cu2+)].
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Affiliation(s)
- Go Nishimura
- Research Center for Solar Energy Chemistry and Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531, Japan
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70
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Affiliation(s)
- Irwin K. Cheah
- a School of Chemistry, Monash University , Victoria, 3800, Australia
| | | | - Melissa J. Latter
- a School of Chemistry, Monash University , Victoria, 3800, Australia
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71
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Liu Y, Jiang W, Zhang HY, Li CJ. A Multifunctional Arithmetical Processor Model Integrated Inside a Single Molecule. J Phys Chem B 2006; 110:14231-5. [PMID: 16854125 DOI: 10.1021/jp061749k] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Improving the processing power of molecules remains the challenge for molecular logic and computation. Here we report a 2-phenylimidazo[4,5-f][1,10]phenanthroline (PIPH)-based three-state molecular switch by controlling its unique emission and absorption spectra in the acid and base condition. On one hand, PIPH can perform simultaneously the functions of an "AND" gate and an "XOR" gate, capable of operating as a half-adder, and the "off-on-off" function as well as comparison function by monitoring its fluorescent spectral changes. On the other hand, the molecule can also implement in parallel the functions of an "XOR" gate and two "INH" gates by monitoring its absorption spectral changes, which constructs two half-subtractors. The cooperative operation of comparator and half-subtractor makes general subtraction operation become possible, which is discussed conceptually in the report.
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Affiliation(s)
- Yu Liu
- Department of Chemistry, State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, P. R. China.
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72
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Margulies D, Melman G, Shanzer A. A Molecular Full-Adder and Full-Subtractor, an Additional Step toward a Moleculator. J Am Chem Soc 2006; 128:4865-71. [PMID: 16594723 DOI: 10.1021/ja058564w] [Citation(s) in RCA: 203] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Over the past decade, there has been remarkable progress in the development of molecular logic and arithmetic systems, which has brought chemists closer to the realization of a molecular scale calculator (a Moleculator). This paper describes a significant step in this direction. By integrating past and new approaches for molecular logic reconfiguration, we were able to load advanced arithmetic calculations onto a single molecular species. Exchanging chemical inputs, monitoring at several wavelengths simultaneously, as well as using negative logic for the transmittance mode significantly increase the input and output information channels of the processing molecule. Changing the initial state of the processor is an additional approach used for altering the logical output of the device. Finally, introducing degeneracy to the chemical inputs or, alternatively, controlling their interactions to form identical chemical states minimizes the complexity of realizing three-bits addition and subtraction at the molecular scale. Consequently, using a commercially available fluorescein molecule, acid and base chemical inputs, and a simple UV-vis measurement setup, integration of a full-adder and, for the first time, a full-subtractor is now possible within individual molecules.
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Affiliation(s)
- David Margulies
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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73
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de Sousa M, de Castro B, Abad S, Miranda MA, Pischel U. A molecular tool kit for the variable design of logic operations (NOR, INH, EnNOR). Chem Commun (Camb) 2006:2051-3. [PMID: 16767272 DOI: 10.1039/b600932h] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple set of five components was used to design molecular logic gates based on phthalimide-sensitised Tb(III) luminescence, including the first report of an enabled NOR (EnNOR) gate.
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Affiliation(s)
- Miguel de Sousa
- REQUIMTE/Departamento de Química, Universidade do Porto, Rua Campo Alegre, 4169-007, Porto, Portugal
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74
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Singh P, Kumar S. Photonic logic gates based on metal ion and proton induced multiple outputs in 5-chloro-8-hydroxyquinoline based tetrapod. NEW J CHEM 2006. [DOI: 10.1039/b607524j] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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75
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Okamoto H, Kohno M, Satake K, Kimura M. An Azacrowned Phthalimide as a Metal-Ion Sensitive and Solvatofluorochromic Fluorophore: Fluorescence Properties and a Mimic Integrated Logic Operation. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2005. [DOI: 10.1246/bcsj.78.2180] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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76
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Coskun A, Deniz E, Akkaya EU. Effective PET and ICT Switching of Boradiazaindacene Emission: A Unimolecular, Emission-Mode, Molecular Half-Subtractor with Reconfigurable Logic Gates. Org Lett 2005; 7:5187-9. [PMID: 16268534 DOI: 10.1021/ol052020h] [Citation(s) in RCA: 260] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction, structure: see text] We report a unimolecular system functioning as a combinatorial logic circuit for half-subtractor. The emission characteristics can be modulated by chemical inputs, and when followed at two different wavelengths, two functionally integrated logic gates XOR and INHIBIT are obtained. Both logic gates function in the emission mode, and with very large differences in the signal intensity allowing unequivocal assignment of logic-0 and logic-1.
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Affiliation(s)
- Ali Coskun
- Department of Chemistry, Middle East Technical University, TR-06531 Ankara, Turkey
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77
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Zhou Y, Zhang D, Zhang Y, Tang Y, Zhu D. Tuning the CD Spectrum and Optical Rotation Value of a New Binaphthalene Molecule with Two Spiropyran Units: Mimicking the Function of a Molecular “AND” Logic Gate and a New Chiral Molecular Switch. J Org Chem 2005; 70:6164-70. [PMID: 16050673 DOI: 10.1021/jo050489k] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
With the view to developing new chiral molecular switches and logic gates, a new binaphthalene molecule with two spiropyran units (1) was synthesized and characterized. Absorption and 1H NMR spectral studies of 1 after reaction with acid/base indicate acidichromism can occur to compound 1. The synergistic actions of acid and UV light irradiation result in a remarkable change for the CD spectrum of the relatively dilute solution of 1, mimicking the behavior of a chiral "AND" gate, since the "ouput" is the CD signal. Furthermore, the optical rotation value of the relatively concentrated solution of 1 can be reversibly tuned after sequential reactions with acid and base, and thus a chiral molecular switch with nondestructive "output" signal is realized. The present results not only add a new example of chiral molecular switch with nondestructive readout but also provide a chiral "AND" gate based on the axial chiral binaphthalene to which switchable units are linked.
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Affiliation(s)
- Yucheng Zhou
- Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
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78
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Sessler JL, Jayawickramarajah J. Functionalized base-pairs: versatile scaffolds for self-assembly. Chem Commun (Camb) 2005:1939-49. [PMID: 15834467 DOI: 10.1039/b418526a] [Citation(s) in RCA: 124] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This article discusses the development of synthetic supramolecular systems derived from hydrogen bond driven base-pairing, with a focus on the self-assembly of individual nucleobase analogues.
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Affiliation(s)
- Jonathan L Sessler
- Department of Chemistry and Biochemistry and Institute for Cellular and Molecular Biology, 1 University Station, A5300, University of Texas at Austin, Austin, Texas 78712-0165, USA.
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79
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80
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Guo X, Zhang D, Tao H, Zhu D. Concatenation of Two Molecular Switches via a Fe(II)/Fe(III) Couple. Org Lett 2004; 6:2491-4. [PMID: 15255673 DOI: 10.1021/ol0494111] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text] Modulation of the fluorescein fluorescence in the presence of spiropyran and ferric ion by light was observed. Such fluorescence modulation was due to the low oxidation potential of complex MC.Fe(2+), which made the electron transfer from MC.Fe(2+) to Flu(+)()(*)() thermodynamically favorable. As a result, the communication between two molecular switches based on fluorescein and spiropyan, respectively, was realized via the reversible Fe(III)/Fe(II) redox couple. The communicating behavior corresponds well to the function of an INHIBIT logic gate.
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Affiliation(s)
- Xuefeng Guo
- Center for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
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81
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Callan JF, De Silva AP, McClenaghan ND. Switching between molecular switch types by module rearrangement: Ca2+-enabled, H+-driven ‘Off–On–Off’, H+-driven YES and PASS 0 as well as H+, Ca2+-driven AND logic operations. Chem Commun (Camb) 2004:2048-9. [PMID: 15367968 DOI: 10.1039/b405909c] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Several logic gates and switches can be accessed from two different combinations of a single set of fluorophore, receptor and spacer components.
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Affiliation(s)
- John F Callan
- School of Chemistry, Queen's University, Belfast, Northern IrelandBT9 5AG. ;
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82
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Abstract
[structure: see text] Chemical and optical stimulations control the interconversion of a three-state molecular switch trapped inside a silica monolith. The resulting absorbance changes in the visible region can be exploited to reproduce a sequential logic operator with one optical input and one optical output. This strategy to transfer operating principles for digital processing from bulk solutions to rigid materials can lead to the development of chemical logic gates based on functional solid components.
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Affiliation(s)
- Silvia Giordani
- Center for Supramolecular Science, Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, USA
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83
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Raymo FM, Giordani S, White AJP, Williams DJ. Digital processing with a three-state molecular switch. J Org Chem 2003; 68:4158-69. [PMID: 12762714 DOI: 10.1021/jo0340455] [Citation(s) in RCA: 144] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Certain molecular switches respond to input stimulations producing detectable outputs. The interplay of these signals can be exploited to reproduce basic logic operations at the molecular level. The transition from simple logic gates to complex digital circuits requires the design of chemical systems able to process multiple inputs and outputs. We have identified a three-state molecular switch that responds to one chemical and two optical inputs producing two optical outputs. We have encoded binary digits in its inputs and outputs applying positive logic conventions and demonstrated that this chemical system converts three-digit input strings into two-digit output strings. The logic function executed by the three-state molecular switch is equivalent to that of a combinational logic circuit integrating two AND, two NOT, and one OR gate. The three states of the molecular switch are a colorless spiropyran, a purple trans-merocyanine, and its yellow-green protonated form. We have elucidated their structures by X-ray crystallography, (1)H NMR spectroscopy, COSY and NOE experiments, as well as density functional calculations. The three input stimulations controlling the interconversion of the three states of the molecular switch are ultraviolet light, visible light, and H(+). The two outputs are the absorption bands in the visible region of the two colored states of the molecular switch. We have monitored the switching processes and quantified the associated thermodynamic and kinetic parameters with the aid of (1)H NMR and visible absorption spectroscopies.
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Affiliation(s)
- Françisco M Raymo
- Center for Supramolecular Science, Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, USA.
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84
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Raymo FM, Alvarado RJ, Giordani S, Cejas MA. Memory effects based on intermolecular photoinduced proton transfer. J Am Chem Soc 2003; 125:2361-4. [PMID: 12590566 DOI: 10.1021/ja027977j] [Citation(s) in RCA: 176] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have identified a strategy to communicate a chemical signal between two independent molecular components. One of them is a photoactive merocyanine that switches to a spiropyran, releasing a proton, when stimulated with visible light. The other is a 4,4'-pyridylpyridinium monocation that captures the released proton, producing an electroactive 4,4'-bipyridinium dication. Under the irradiation conditions employed, the photoinduced transformation requires ca. 15 min to reach a photostationary state. In the dark, the ensemble of communicating molecules reequilibrates to the original state in ca. 5 days. These processes can be monitored following the photoinduced enhancement and thermal decay, respectively, of the current for the monolectronic reduction of the 4,4'-bipyridinium dication. The pronounced difference in time scale for the current enhancement and decay steps can be exploited to implement a memory element with a bit retention time of 11 h. A bit of information can be written optically in the chemical system and it can be read electrically and nondestructively. The memory can be reset, extending its permanence in the dark beyond the bit retention time. A binary logic analysis of the signal transduction operated by the communicating molecules reveals the characteristic behavior of sequential logic operators, which are the basic components of digital memories.
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Affiliation(s)
- Françisco M Raymo
- Center for Supramolecular Science, Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146-0431, USA.
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85
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de Silva AP, McCaughan B, McKinney BOF, Querol M. Newer optical-based molecular devices from older coordination chemistry. Dalton Trans 2003. [DOI: 10.1039/b212447p] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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86
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Abstract
[reaction: see text] Bright green boradiazaindacene fluorescence is quenched by an oxidative photoinduced electron transfer (PET) from the excited state fluorophore to the bipyridyl unit complexed to metal cations. The closed shell diamagnetic cation Zn(II) is one of the most effective quenchers of fluorescence in this system, demonstrating that the quenching is not simply related to the facilitated intersystem crossing. The molecule also acts as a NOR logic gate with two chemical inputs, TFA and Zn(II).
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Affiliation(s)
- Bilge Turfan
- Department of Chemistry, Middle East Technical University, Ankara TR-06531, Turkey
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Baki CN, Akkaya EU. Boradiazaindacene-appended calix[4]arene: fluorescence sensing of pH near neutrality. J Org Chem 2001; 66:1512-3. [PMID: 11312992 DOI: 10.1021/jo005706q] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- C N Baki
- Middle East Technical University, Department of Chemistry, TR-06531, Ankara, Turkey
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