| 1. |
- Kärnbratt, Joakim, 1982, et al.
(författare)
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Photochromic Supramolecular Memory With Nondestructive Readout
- 2010
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Ingår i: Angewandte Chemie - International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 49:10, s. 1854-1857
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Tidskriftsartikel (refereegranskat)abstract
- Looking without touching: The light-controlled isomerization of a complex containing a pyridine-appended dithienylethene (DTE; green) and a porphyrin dimer induces dramatic structural and spectral changes (see picture). These changes are monitored in a region outside the photochromically active absorption bands of DTE, therefore allowing a nondestructive readout so that the process functions as a molecular optically controlled memory.
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| 2. |
- Andreasson, Joakim, 1973, et al.
(författare)
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A dihydroindolizine-porphyrin dyad as molecule-based all-photonic AND and NAND gates
- 2011
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Ingår i: Dyes and Pigments. - : Elsevier BV. - 0143-7208 .- 1873-3743. ; 89:3, s. 284-289
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Tidskriftsartikel (refereegranskat)abstract
- A molecular dyad consisting of a photochromic dihydroindolizine unit covalently linked to a porphyrin performs, when illuminated through a third-harmonic-generating crystal, the functions of both an AND and a NAND Boolean logic gate with shared all-optical inputs. The NAND gate is of particular interest as it is a so-called universal gate, and hence all other digital systems can be implemented by combinations of NAND gates. The functions of the AND and the NAND gates rely on changes in absorption and emission of the dyad in the visible spectral region upon isomerization of the photochromic unit. The change in absorption which forms the basis for the AND gate function is ascribed to the colorization/decolorization of the photochrome itself in response to the optical inputs. The variation in emission intensity which constitutes the NAND gate function is a result of the changes in redox properties of the photochrome that follow upon isomerization, such that only one of the two isomers is competent to quench the porphyrin emission by electron transfer.
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| 3. |
- Andreasson, Joakim, 1973, et al.
(författare)
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A simplicity-guided approach toward molecular set-reset memories
- 2010
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Ingår i: New Journal of Chemistry. - : Royal Society of Chemistry (RSC). - 1369-9261 .- 1144-0546. ; 34:12, s. 2701-2703
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Tidskriftsartikel (refereegranskat)abstract
- Photochromic switches fulfill the general molecular design criteria for the surprisingly straightforward small-scale integration of seemingly complex set-reset latches. The implications of this re-interpretation are discussed with the example of a dithienylethene photochrome. The concept is shown to be valid for a multitude of well-introduced bistable switches with clearly differentiated output signals, e.g., optical signals for the presented example.
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| 4. |
- Andreasson, Joakim, 1973, et al.
(författare)
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All-Photonic Multifunctional Molecular Logic Device
- 2011
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 133:30, s. 11641-11648
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Tidskriftsartikel (refereegranskat)abstract
- Photochromes are photoswitchable, bistable chromophores which, like transistors, can implement binary logic operations. When several photochromes are combined in one molecule, interactions between them such as energy and electron transfer allow design of simple Boolean logic gates and more complex logic devices with all-photonic inputs and outputs. Selective isomerization of individual photochromes can be achieved using light of different wavelengths, and logic outputs can employ absorption and emission properties at different wavelengths, thus allowing a single molecular species to perform several different functions, even simultaneously. Here, we report a molecule consisting of three linked photochromes that can be configured as AND, XOR, INH, half-adder, half-subtractor, multiplexer, demultiplexer, encoder, decoder, keypad lock, and logically reversible transfer gate logic devices, all with a common initial state. The system demonstrates the advantages of light-responsive molecules as multifunctional, reconfigurable nanoscale logic devices that represent an approach to true molecular information processing units.
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| 5. |
- Andreasson, Joakim, 1973, et al.
(författare)
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Photonically Switched Molecular Logic Devices
- 2013
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Ingår i: Molecular and Supramolecular Information Processing: From Molecular Switches to Logic Systems (ed E. Katz). - : Wiley. - 9783527331956 ; , s. 53-78
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Photochromic molecules are bistable chromophores wherein the interconversions between the two states are triggered by exposure to light of different wavelengths. Hence, they are considered as potential candidates to be used as all-photonic molecular logic devices. This chapter describes our proof-of-principle realizations of photochromically controlled logic functions, from basic on-off switches via Boolean logic gates to the implementation of small logic circuits such as the half-adder/half-subtractor, multiplexer/demultiplexer, and encoder/decoder.
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| 6. |
- Andreasson, Joakim, 1973, et al.
(författare)
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Smart molecules at work-mimicking advanced logic operations
- 2010
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Ingår i: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 1460-4744 .- 0306-0012. ; 39:1, s. 174-188
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Tidskriftsartikel (refereegranskat)abstract
- Molecular logic is an interdisciplinary research field, which has captured worldwide interest. This tutorial review gives a brief introduction into molecular logic and Boolean algebra. This serves as the basis for a discussion of the state-of-the-art and future challenges in the field. Representative examples from the most recent literature including adders/subtractors, multiplexers/demultiplexers, encoders/decoders, and sequential logic devices (keypad locks) are highlighted. Other horizons, such as the utility of molecular logic in bio-related applications, are discussed as well.
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| 7. |
- Andreasson, Joakim, 1973, et al.
(författare)
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Storage and Processing of Information Using Molecules: The All-Photonic Approach with Simple and Multi-Photochromic Switches
- 2013
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Ingår i: Israel Journal of Chemistry. - : Wiley. - 0021-2148. ; 53:5, s. 236-246
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Forskningsöversikt (refereegranskat)abstract
- The use of photochromes for the implementation of molecular logic operations is a very promising approach toward molecular computing. This statement is based on a) the possibility of operating such molecular devices exclusively with photonic signals and b) spatiotemporally and remotely controlled switching, which is characteristic for photochromes. Herein, a brief overview of the application of simple photochromes and multi-photochromic conjugates for the small-scale functional integration of complicated logic circuits is given. This complements and extends efforts to design molecular photochromic memories for data storage described by many research groups worldwide.
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| 8. |
- Bälter, Magnus, 1986, et al.
(författare)
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An All-Photonic Molecule-Based Parity Generator/Checker for Error Detection in Data Transmission
- 2013
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 135:28, s. 10230-10233
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Tidskriftsartikel (refereegranskat)abstract
- The function of a parity generator/checker, which is an essential operation for detecting errors in data transmission, has been realized with multiphotochromic switches by taking advantage of a neuron-like fluorescence response and reversible light-induced transformations between the implicated isomers.
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| 9. |
- Ding, Yubin, et al.
(författare)
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Acid/Base Switching of the Tautomerism and Conformation of a Dioxoporphyrin for Integrated Binary Subtraction
- 2014
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 20:40, s. 12910-12916
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Tidskriftsartikel (refereegranskat)abstract
- Compared with most of the reported logic devices based on the supramolecular approach, systems based on individual molecules can avoid challenging construction requirements. Herein, a novel dioxoporphyrin DPH22 was synthesized and two of its tautomers were characterized by single-crystal X-ray diffraction studies. Compound DPH22 exhibits multichannel controllable stepwise tautomerization, protonation, and deprotonation processes through interactions with H and F- ions. By using the addition of H+ and F- ions as inputs and UVNis absorption values at.1=412, 510, 562, and 603 nm as outputs, the controlled tautomerism of DPH22 has been successfully used for the construction of an integrated molecular level half-subtractor and comparator. In addition, this acid/base-switched tautomerism is reversible, thus endowing the system with ease of reset and recycling; consequently, there is no need to modulate complicated intermolecular interactions and electron-/chargetransfer processes.
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| 10. |
- Ferreira, Raphael, 1990, et al.
(författare)
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Photoswitch kinase inhibitors
- 2014
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Ingår i: Purinergic Signalling. - 1573-9538 .- 1573-9546. ; 10:4, s. 767-768
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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