scholarly journals Optical gating with organic building blocks. A quantitative model for the fluorescence modulation of photochromic perylene bisimide dithienylcyclopentene triads

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Martti Pärs ◽  
Michael Gradmann ◽  
Katja Gräf ◽  
Peter Bauer ◽  
Mukundan Thelakkat ◽  
...  
Keyword(s):  
Building Blocks ◽  
Quantitative Model ◽  
Optical Gating ◽  
Perylene Bisimide ◽  
Fluorescence Modulation

scholarly journals Correction: Reversible fluorescence modulation through the photoisomerization of an azobenzene-bridged perylene bisimide cyclophane

2021 ◽  
Author(s):  
Guanghui Ouyang ◽  
David Bialas ◽  
Frank Würthner
Keyword(s):  
Perylene Bisimide ◽  
Fluorescence Modulation

Correction for ‘Reversible fluorescence modulation through the photoisomerization of an azobenzene-bridged perylene bisimide cyclophane’ by Guanghui Ouyang et al., Org. Chem. Front., 2021, DOI: 10.1039/D0QO01635G.

scholarly journals Fluorescence modulation by fast photochromism of a [2.2]paracyclophane-bridged imidazole dimer possessing a perylene bisimide moiety

2018 ◽  
Vol 6 (35) ◽  
pp. 9523-9531 ◽  
Author(s):  
Katsuya Mutoh ◽  
Michel Sliwa ◽  
Eduard Fron ◽  
Johan Hofkens ◽  
Jiro Abe
Keyword(s):  
Perylene Bisimide ◽  
Red Color ◽  
Fluorescence Switching ◽  
Fluorescence Modulation

We demonstrated the red-color fluorescence switching of a perylene bisimide (PBI) derivative by using a fast photochromic [2.2]paracyclophane-bridged imidazole dimer.

Optical gating of perylene bisimide fluorescence using dithienylcyclopentene photochromic switches

2013 ◽  
Vol 103 (22) ◽  
pp. 221115 ◽  
Author(s):  
Martti Pärs ◽  
Katja Gräf ◽  
Peter Bauer ◽  
Mukundan Thelakkat ◽  
Jürgen Köhler
Keyword(s):  
Optical Gating ◽  
Perylene Bisimide

scholarly journals Towards an Analysis of Efficiency in Research, The Case of Colombian Universities

2019 ◽  
Vol 21 (2) ◽  
pp. 1-10
Author(s):  
Victor Bucheli
Keyword(s):  
Economies Of Scale ◽  
Returns To Scale ◽  
Building Blocks ◽  
Quantitative Model ◽  
Growth Patterns ◽  
Knowledge Generation ◽  
Scaling Exponents ◽  
Increasing Returns To Scale ◽  
Research Activities ◽  
Living Organisms

The aim of this paper is to study the empirical evidence of common growth patterns in total publications by year and the scaling exponents (β) associated with this growth behavior. Furthermore, research activities seem to show increasing returns to scale, and the research networks related to these knowledge generation activities appear to show economies of scale. This paper discusses whether the behavior of efficiency Colombian university institutions resemble the behavior of living organisms. Thus, the efficiency name as total publications by sizes institution, is associated to the scaling coefficients. In addition, this work provides the building blocks for a quantitative model, in which, the observed scalability emerge from the capacity to attract Ph.D. students or create new links to carried out research activities in networks.

scholarly journals Switching or blinking? – The switching behaviour of single photochromic triads

2018 ◽  
Vol 190 ◽  
pp. 04014
Author(s):  
Johannes Maier ◽  
Martti Pärs ◽  
Tina Weller ◽  
Mukundan Thelakkat ◽  
Jürgen Köhler
Keyword(s):  
Super Resolution ◽  
Building Blocks ◽  
Perylene Bisimide ◽  
Switching Behaviour ◽  
Fluorescence Characteristics ◽  
Photochromic Molecules ◽  
Covalently Linked ◽  
Switching Characteristics ◽  
Super Resolution Microscopy

Photochromic molecules can be interconverted between two bistable conformations by light [1–3]. Irie and coworkers described a strategy to achieve superior fluorescence characteristics and outstanding switching characteristics of a photochromic unit by linking strong fluorophores covalently to photochromic building blocks [3,4]. Accordingly, we synthesised molecular triads that consist of two perylene bisimide (PBI) fluorophores covalently linked to a dithienylcyclopentene (DCP) photochromic switch, see fig. 1. Such kinds of triads are promising candidates for super-resolution microscopy like RESOLFT and PALM [5,6], or can be used as optical transistors or memories [4,7].

Energy transfer within self-assembled cyclic multichromophoric arrays based on orthogonally arranged donor–acceptor building blocks

2015 ◽  
Vol 185 ◽  
pp. 433-454 ◽  
Author(s):  
Nikolaos Karakostas ◽  
Antonia Kaloudi-Chantzea ◽  
Elisabeth Martinou ◽  
Kostas Seintis ◽  
Florian Pitterl ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Excitation Energy ◽  
Building Blocks ◽  
Electronic Excitation Energy ◽  
Efficient Energy Transfer ◽  
Time Resolved ◽  
Perylene Bisimide ◽  
Polygonal Chain ◽  
Structural Deformations ◽  
Donor Acceptor

We herein present the coordination-driven supramolecular synthesis and photophysics of a [4+4] and a [2+2] assembly, built up by alternately collocated donor–acceptor chromophoric building blocks based, respectively, on the boron dipyrromethane (Bodipy) and perylene bisimide dye (PBI). In these multichromophoric scaffolds, the intensely absorbing/emitting dipoles of the Bodipy subunit are, by construction, cyclically arranged at the corners and aligned perpendicular to the plane formed by the closed polygonal chain comprising the PBI units. Steady-state and fs time-resolved spectroscopy reveal the presence of efficient energy transfer from the vertices (Bodipys) to the edges (PBIs) of the polygons. Fast excitation energy hopping – leading to a rapid excited state equilibrium among the low energy perylene-bisimide chromophores – is revealed by fluorescence anisotropy decays. The dynamics of electronic excitation energy hopping between the PBI subunits was approximated on the basis of a theoretical model within the framework of Förster energy transfer theory. All energy-transfer processes are quantitatively describable with Förster theory. The influence of structural deformations and orientational fluctuations of the dipoles in certain kinetic schemes is discussed.

scholarly journals Fertility versus productivity: a model of growth with evolutionary equilibria

2020 ◽  
Author(s):  
James Foreman-Peck ◽  
Peng Zhou
Keyword(s):  
Industrial Revolution ◽  
Fertility Transition ◽  
Building Blocks ◽  
Quantitative Model ◽  
Elasticity Of Substitution ◽  
Growth Theory ◽  
Investment In Children ◽  
Economic Stagnation ◽  
Target Family ◽  
Malthusian Trap

AbstractWe develop a quantitative model that is consistent with three principal building blocks of Unified Growth Theory: the break-out from economic stagnation, the build-up to the Industrial Revolution, and the onset of the fertility transition. Our analysis suggests that England’s escape from the Malthusian trap was triggered by the demographic catastrophes in the aftermath of the Black Death; household investment in children ultimately raised wages despite an increasing population; and rising human capital, combined with the increasing elasticity of substitution between child quantity and quality, reduced target family size and contributed to the fertility transition.

scholarly journals Design, synthesis and structure of novel G-2 melamine-based dendrimers incorporating 4-(n-octyloxy)aniline as a peripheral unit

2018 ◽  
Vol 14 ◽  
pp. 1704-1722 ◽  
Author(s):  
Cristina Morar ◽  
Pedro Lameiras ◽  
Attila Bende ◽  
Gabriel Katona ◽  
Emese Gál ◽  
...  
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Tem Analysis ◽  
Design Synthesis ◽  
Perylene Bisimide ◽  
Self Assembling ◽  
Chemoselective Synthesis ◽  
Azobenzene Mesogens ◽  
Vt Nmr ◽  
Peripheral Unit

Background: 4-(n-Octyloxy)aniline is a known component in the elaboration of organic materials with mesogenic properties such as N-substituted Schiff bases, perylene bisimide assemblies with a number of 2-amino-4,6-bis[4-(n-octyloxy)phenylamino]-s-triazines, amphiphilic azobenzene-containing linear-dendritic block copolymers and G-0 monomeric or dimeric dendritic liquid crystals with photochromic azobenzene mesogens. The present ab initio study explores a previously unknown use of 4-(n-octyloxy)aniline in the synthesis, structure and supramolecular behaviour of new dendritic melamines. Results: Starting from 4-(n-octyloxy)aniline, seven G-2 melamine-based dendrimers were obtained in 29–79% overall yields. Their iterative convergent- and chemoselective synthesis consisted of SN2-Ar aminations of cyanuric chloride and final triple N-acylations and Williamson etherifications (→ G-2 covalent trimers) or stoichiometric carboxyl/amino 1:3 neutralisations (→ G-2 ionic trimers). These transformations connected G-1 chloro- and amino-termini dendrons to m-trivalent cores (triazin-2,4,6-triyl and benzene-1,3,5-triyl units) or tripodands (central building blocks), such as N-substituted melamines with 4-hydroxyphenyl or phenyl-4-oxyalkanoic motifs. Owing to the diversity of cores and central building blocks, the structural assortment of the dendritic series was disclosed by solvation effects (affecting reactivity), rotational stereodynamism and self-organisation phenomena (determining a vaulted and/or propeller macromolecular shape in solution). DFT calculations (in solution), (VT) NMR and IR (KBr) spectroscopy supported these assignments. TEM analysis revealed the ability of the title compounds towards self-assembling into homogeneously packed spherical nano-aggregates. Conclusions: The (non)covalent synthesis and step-by-step structural elucidation of novel G-2 melamine dendrimers based on 4-(n-octyloxy)aniline are reported. Our study demonstrates the crucial influence of the nature (covalent vs ionic) of the dendritic construction in tandem with that of its central building blocks on the aptitude of dendrimers to self-organise in solution and to self-assembly in the solid state.

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