Publications associées à Preparation of cationic azo compounds

Synthesis of NIR-Absorbing Squaraine Dyes and their Use in Organic Upconversion Devices

Squaraines are organic dyes showing the advantages of a simple synthesis, high absorption coefficients and tunable bandgaps from the visible to the near-infrared (NIR) region. Their molecular structure is based on a polymethine chain and a donor-acceptor-d ...

EPFL2021

Carbazol-phenyl-phenothiazine-based sensitizers for dye-sensitized solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yi Ding, Wei Huang, Dan Ren, Felix Thomas Eickemeyer, Zhongjin Shen, Yunfei Jiao, Lukas Pfeifer

Heteroaromatic units are commonly used as pi-spacers for sensitizers in dye-sensitized solar cells (DSSCs). Here, we investigated the influence of the pi-spacer on the photophysical properties, electrochemical properties and photovoltaic performance of car ...

Royal Society of Chemistry2021

A 512 x 512 SPAD Image Sensor With Integrated Gating for Widefield FLIM

Claudio Bruschini, Edoardo Charbon, Ivan Michel Antolovic, Arin Can Ülkü

In this paper, we report on SwissSPAD2, an image sensor with 512 x 512 photon-counting pixels, each comprising a single-photon avalanche diode (SPAD), a 1-b memory, and a gating mechanism capable of turning the SPAD ON and OFF, with a skew of 250 and 344 p ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2019

Dyes, Radicals and Nitrous Oxide Adducts Derived from N-Heterocyclic Carbenes

Léonard Yannick Maurice Eymann

N-Heterocyclic carbenes are able to form covalent adducts with nitrous oxide (N2O) under ambient conditions. This thesis summarizes the studies of these adducts and their reactivity. A ditopic carbanionic N-heterocyclic carbene was found to react with nit ...

EPFL2018

Effect of Chaotropes on the Transfer of Ions and Dyes across the Liquid–Liquid Interface

Hubert Girault, Grégoire Clément Gschwend, Pekka Eero Peljo, Evgeny Smirnov, Lucie Josette Renée Rivier, Elena Vladimirova

Chaotropes such as urea can break the structure of water, weakening the hydrophobic effect and reducing aggregation. Here, we investigated how the addition of urea affects the transfer of ions and cationic dyes across the interface between immiscible elect ...

2018

Lateral Intermolecular Electronic Interactions of Diketopyrrolopyrrole D−π–A Solar Dye Sensitizers Adsorbed on Mesoporous Alumina

Jacques-Edouard Moser, Ulf Anders Hagfeldt, Heewon Bahng

The development of push−pull organic dyes utilizing the donor−(π-conjugated bridge)−acceptor (D−π−A) motif has induced a paradigm shift in the design of efficient nanocrystalline dye-sensitized solar cells (DSSCs), offering control over the aesthetic prope ...

2018

Photoanode/Electrolyte Interface Stability in Aqueous Dye-Sensitized Solar Cells

Michael Graetzel, Guido Viscardi

O'Regan and Gratzel conceived a dye-sensitized solar cell (DSSC), which operates as an artificial photosynthetic system converting solar light into electricity. Nevertheless, it is only recently that the scientific community is focusing on truly aqueous DS ...

Wiley-V C H Verlag Gmbh2017

Significance of pi-bridge contribution in pyrido[3,4-b]pyrazine featured D-A-pi-A organic dyes for dye-sensitized solar cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Yelin Hu, Fabrizio Giordano, Xiaoyu Zhang, Zhongjin Shen

The 3,4-ethylenedioxythiophene (EDOT) pi-bridge is one of the most commonly used building blocks for sensitizers in dye-sensitized solar cells (DSSCs). We investigated its influence on the molecular structure, the photophysical and electrochemical properti ...

Chinese Chemical Soc2017

Pyridyl- and Picolinic Acid Substituted Zinc(II) Phthalocyanines for Dye-Sensitized Solar Cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Jun Ho Yum, Aravind Kumar Chandiran

A series of tri-tert-butyl zinc(II) phthalocyanines (Pcs) substituted with pyridyl, carboxyl, or picolinic acid anchoring groups on the periphery were prepared. Photovoltaic (PV) studies on these dyes were carried out revealing some interesting features. I ...

Wiley-VCH Verlag2017

Rationalizing Fluorescence Quenching in meso-BODIPY Dyes

Anne-Clémence Corminboeuf, Alberto Fabrizio, Antonio Prlj

meso-Substituted boron-dipyrromethene (BODIPY) dyes are a puzzling class of molecules, which feature contrasting emissive behaviors. The full mechanistic picture for these distinctive properties is still missing. Using static and dynamic excited state comp ...

Royal Soc Chemistry2016

A study of oligothiophene-acceptor dyes in p-type dye-sensitized solar cells

Ulf Anders Hagfeldt, Peng Liu, Lei Zhang

Two new dyes, E1 and E2, equipped with triphenylamine as the electron donor, oligothiophene as the linker and different electron acceptor groups, have been designed and synthesized as photosensitizers for p-type dye-sensitized solar cells (p-DSCs). A syste ...

Royal Soc Chemistry2016

Array-based sensing of purine derivatives with fluorescent dyes

Kay Severin, Ziya Köstereli

Natural and synthetic purine derivatives such as caffeine, theophylline, 6-mercaptopurine and 8-chlorotheophylline are important drugs. Due to the structural similarity of these compounds, it is intrinsically difficult to prepare chemosensors for their sel ...

Royal Soc Chemistry2015

Influence of DNA Binding Dyes on Bare DNA Structure Studied with Atomic Force Microscopy

Giovanni Dietler, Aleksandre Japaridze, Sylvain Renevey, Aleksandr Benke

Fluorescent dyes are widely used for staining and visualization of DNA in optical microscopy based methods. Even though for some dyes the mechanism of binding is known, how this binding affects DNA remains poorly understood. Here we present a novel experim ...

American Chemical Society2015

Selective detection of Al3+ and citric acid with a fluorescent amphiphile

Kay Severin, Ziya Köstereli

An amphiphilic fluorescent dye with a disulfonated BODIPY head group and a heptadecyl side chain is described. In buffered aqueous solution, the amphiphile can form aggregates with a critical micelle concentration of similar to 20 mu M. The aggregation of ...

Royal Society of Chemistry2015

Design of Ru(II) sensitizers endowed by three anchoring units for adsorption mode and light harvesting optimization

Mohammad Khaja Nazeeruddin, Filippo de Angelis

We report the design, synthesis and computational investigation of a class of Ru(II)-dyes based on mixed bipyridine ligands for use in dye-sensitized solar cells. These dyes are designed to preserve the optimal anchoring mode of the prototypical N719 sensi ...

Elsevier2014

Photocatalytic degradation of Remazol Brilliant Blue (R) by sol-gel derived carbon-doped TiO2

Ravindranathan Thampi, Michael Jon Mattle

A simple, cheap and reproducible method to produce a C-doped TiO2 photocatalyst is presented, which can harvest visible light. This doped catalyst is able to degrade a stable organic dye molecule, Remazol Brilliant Blue (R) (RBB), under sunlight and visibl ...

Elsevier Science Bv2013

Molecular Engineering of Organic Dyes for Improved Recombination Lifetime in Solid-State Dye-Sensitized Solar Cells

Michael Graetzel, Thomas Moehl, Julian Burschka

A major limitation of solid-state dye-sensitized solar cells is a short electron diffusion length, which is due to fast recombination between electrons in the TiO2 electron-transporting layer and holes in the 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine) ...

American Chemical Society2013

UV-patternable polymers with selective spectral response

Jürgen Brugger, Victor Javier Cadarso Busto

We present the characterization of dyed doped/modified Epocore resist (Microresist Technology, Germany) with three commercially-available dyes (Proquimac Color, Spain). After being doped with lilac, red and yellow dyes in a 1:2500 ratio (dye:Epocore, w:w), ...

Elsevier2012

Measured binding coefficients for iodine and ruthenium dyes; implications for recombination in dye sensitised solar cells

Shaik Mohammed Zakeeruddin, Robin Humphry-Baker, Xiong Li, Filippo de Angelis

We have measured the binding coefficients of iodine to three dyes used in Dye Sensitised Solar Cells (DSSCs). Binding coefficients are quantified via the effect of iodine binding on the UV-vis spectrum of the dye. From iodine titration curves of dye sensit ...

Royal Society of Chemistry2012

A ratiometric fluorescence sensor for caffeine

Kay Severin, Anne-Clémence Corminboeuf, Nicolas Luisier, Nicolas David Gaeng, Laurane Favre, Albert Ruggi

The dye disodium 3,4:3’,4’-bibenzo[b]thiophene-2,2’-disulfonate can be used as molecular probe for the fluorimetric detection of caffeine in aqueous solution. The fluorescence response is attributed to non-covalent interactions of caffeine with the dye in ...

Royal Society of Chemistry2012