Chapter 10. Interlocked Artificial Photosynthetic Model Systems Composed of Electron-Donor and [60]Fullerene Units

2011 ◽  
pp. 354-385 ◽  
Author(s):  
Jackson D. Megiatto, Jr. ◽  
David I. Schuster
Keyword(s):  
Electron Donor ◽  
Model Systems ◽  
Artificial Photosynthetic

scholarly journals A Brief History of Photoactive Interlocked Systems Assembled by Transition Metal Template Synthesis

Photochem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 411-433
Author(s):  
Vitor H. Rigolin ◽  
Liniquer A. Fontana ◽  
Jackson D. Megiatto
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Electron Donor ◽  
Metal Ion ◽  
Energy And Electron Transfer ◽  
Donor Acceptor ◽  
History Of ◽  
Artificial Photosynthetic ◽  
Covalently Linked ◽  
Electron Transfer Processes

More than three decades of research efforts have yielded powerful methodologies based on transition metal template-directed syntheses for the assembly of a huge number of interlocked systems, molecular knots, machines and synthesizers. Such template techniques have been applied in the preparation of mechanically linked electron donor–acceptor artificial photosynthetic models. Consequently, synthetic challenging photoactive rotaxanes and catenanes have been reported, in which the chromophores are not covalently linked but are still associated with undergoing sequential energy (EnT) and electron transfer (ET) processes upon photoexcitation. Many interlocked photosynthetic models produce highly energetic, but still long-living charge separated states (CSS). The present work describes in a historical perspective some key advances in the field of photoactive interlocked systems assembled by transition metal template techniques, which illustrate the usefulness of rotaxanes and catenanes as molecular scaffolds to organize electron donor–acceptor groups. The effects of molecular dynamics, molecular topology, as well as the role of the transition metal ion used as template species, on the thermodynamic and kinetic parameters of the photoinduced energy and electron transfer processes in the interlocked systems are also discussed.

Synthesis and Emission Properties of meso-Substituted Porphyrins

2014 ◽  
Vol 71 (1) ◽  
Author(s):  
Tan Ke Xin ◽  
Hendrik O. Lintang ◽  
Abdul Rahman Tamuri ◽  
Salasiah Endud ◽  
Mohd Bakri Bakar
Keyword(s):  
Electron Transfer ◽  
Organic Dyes ◽  
Red Light ◽  
Emission Spectra ◽  
Model Systems ◽  
Fluorescent Properties ◽  
Light Emitting ◽  
Absorption Energy ◽  
Energy And Electron Transfer ◽  
Artificial Photosynthetic

Discovering of various organic dyes including porphyrins have attracted considerable attention to mimic the energy and electron transfer process for the artificial photosynthetic model systems which can be applied in developing optoelectronic devices. The accessibility on tailoring porphyrin properties makes them a good candidate to, be developed as the red light emitting materials for these applications. Thus, symmetrical and unsymmetrical molecular models of porphyrins with appended fluorenyl components and extended π electrons conjugated system were synthesized towards increasing the efficiency of energy and electron transfer. In the photophysical studies, the emission spectra proposed the evidence of energy transfer of appended fluorenyl arms into the porphyrin macrocyclic whereas the extension of conjugating system in porphyrins exhibits lower absorption energy and intensified the red fluorescent properties.

Gated Dissipative Dynamic Artificial Photosynthetic Model Systems

2021 ◽  
Author(s):  
Chen Wang ◽  
Zhixin Zhou ◽  
Yu Ouyang ◽  
Jianbang Wang ◽  
Ehud Neumann ◽  
...  
Keyword(s):  
Model Systems ◽  
Artificial Photosynthetic ◽  
Dissipative Dynamic

scholarly journals Tubular J-aggregates of cyanine dyes in the near-infrared

2021 ◽  
Author(s):  
Austin Bailey ◽  
Arundhati Deshmukh ◽  
Timothy Atallah ◽  
Ulugbek Barotov ◽  
Monica Pengshung ◽  
...  
Keyword(s):  
Self Assembly ◽  
Near Infrared ◽  
Chemical Space ◽  
Photophysical Properties ◽  
Model Systems ◽  
Cyanine Dye ◽  
Infrared Emitters ◽  
Photosynthetic Complexes ◽  
Infrared Wavelengths ◽  
Artificial Photosynthetic

Developing improved organic infrared emitters has wide-ranging applicability in fields such as bioimaging or energy harvesting. We synthesize redshifted analogues of C8S3, a well-known cyanine dye that self assembles into tubular aggregates which have attracted widespread attention as artificial photosynthetic complexes. Despite the elongated dye structure, the new pentamethine dyes retain their tubular self-assembly and emit at near-infrared wavelengths. Cryo-electron microscopy and detailed photophysical characterization of the new aggregates reveal similar absorption lineshapes with ~100 nm of redshift, as well as supramolecular morphologies that resemble their trimethine counterparts; the pentamethine aggregates generally show more disorder and decreased superradiance, suggesting that more ordered structures yield more robust photophysical properties. These results provide design principles of superradiant organic emitters, expand the chemical space of near-infrared aggregates, and introduce two additional wavelength-specific antennae as model systems for study.

scholarly journals Synergy of Electrostatic and π–π Interactions in the Realization of Nanoscale Artificial Photosynthetic Model Systems

2020 ◽  
Vol 59 (42) ◽  
pp. 18786-18794 ◽  
Author(s):  
Eduardo Anaya‐Plaza ◽  
Jan Joseph ◽  
Stefan Bauroth ◽  
Maximilian Wagner ◽  
Christian Dolle ◽  
...  
Keyword(s):  
Model Systems ◽  
Π Interactions ◽  
Artificial Photosynthetic

Subphthalocyanines as Light-Harvesting Electron Donor and Electron Acceptor in Artificial Photosynthetic Systems

2012 ◽  
Vol 116 (37) ◽  
pp. 19709-19717 ◽  
Author(s):  
Mohamed E. El-Khouly ◽  
Jong-Hyung Kim ◽  
Jung-Hoon Kim ◽  
Kwang-Yol Kay ◽  
Shunichi Fukuzumi
Keyword(s):  
Electron Donor ◽  
Electron Acceptor ◽  
Light Harvesting ◽  
Artificial Photosynthetic

scholarly journals Tubular J-aggregates of cyanine dyes in the near-infrared

2021 ◽  
Author(s):  
Austin Bailey ◽  
Arundhati Deshmukh ◽  
Timothy Atallah ◽  
Ulugbek Barotov ◽  
Monica Pengshung ◽  
...  
Keyword(s):  
Self Assembly ◽  
Near Infrared ◽  
Chemical Space ◽  
Photophysical Properties ◽  
Model Systems ◽  
Cyanine Dye ◽  
Infrared Emitters ◽  
Photosynthetic Complexes ◽  
Infrared Wavelengths ◽  
Artificial Photosynthetic

Developing improved organic infrared emitters has wide-ranging applicability in fields such as bioimaging or energy harvesting. We synthesize redshifted analogues of C8S3, a well-known cyanine dye that self assembles into tubular aggregates which have attracted widespread attention as artificial photosynthetic complexes. Despite the elongated dye structure, the new pentamethine dyes retain their tubular self-assembly and emit at near-infrared wavelengths. Cryo-electron microscopy and detailed photophysical characterization of the new aggregates reveal similar absorption lineshapes with ~100 nm of redshift, as well as supramolecular morphologies that resemble their trimethine counterparts; the pentamethine aggregates generally show more disorder and decreased superradiance, suggesting that more ordered structures yield more robust photophysical properties. These results provide design principles of superradiant organic emitters, expand the chemical space of near-infrared aggregates, and introduce two additional wavelength-specific antennae as model systems for study.

Nuclear coiled bodies and the nucleolus

1994 ◽  
Vol 52 ◽  
pp. 20-21
Author(s):  
K. Brasch ◽  
J. Williams ◽  
D. Gallo ◽  
T. Lee ◽  
R. L. Ochs
Keyword(s):  
Mouse Liver ◽  
Nuclear Body ◽  
Nuclear Bodies ◽  
Model Systems ◽  
Coiled Body ◽  
Rrna Processing ◽  
Malignant Cells ◽  
Sm Proteins ◽  
Coiled Bodies ◽  
Unique Protein

Though first described in 1903 by Ramon-y-Cajal as silver-staining “accessory bodies” to nucleoli, nuclear bodies were subsequently rediscovered by electron microscopy about 30 years ago. Nuclear bodies are ubiquitous, but seem most abundant in hyperactive and malignant cells. The best studied type of nuclear body is the coiled body (CB), so termed due to characteristic morphology and content of a unique protein, p80-coilin (Fig.1). While no specific functions have as yet been assigned to CBs, they contain spliceosome snRNAs and proteins, and also the nucleolar protein fibrillarin. In addition, there is mounting evidence that CBs arise from or are generated near the nucleolus and then migrate into the nucleoplasm. This suggests that as yet undefined links may exist, between nucleolar pre-rRNA processing events and the spliceosome-associated Sm proteins in CBs.We are examining CB and nucleolar changes in three diverse model systems: (1) estrogen stimulated chick liver, (2) normal and neoplastic cells, and (3) polyploid mouse liver.

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