Diketopyrrolopyrrole (DPP) Pigments

Wallquist, O.; Lenz, R.

doi:10.1002/9783527626915.ch11

Cited by 6 publications

(5 citation statements)

References 38 publications

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“…The diketopyrrollopyrrole (DPP) unit is one of the most popular and important chromophores for use in light absorbing and optoelectronically active materials. Since its original usage as color pigment in paint formulations, manifold applications from organic photovoltaics − to organic field-effect transistors (OFET), , sensors , or near-IR probes for biomedical purposes have been pursued, whereby the dithienyl-flanked DPP chromophore, hereafter referred to as DPPTh 2 , is mostly used. When incorporated into alternating copolymers, DPPTh 2 -based materials exhibit small bandgaps, excellent charge carrier mobility and photovoltaic performance.…”

Section: Introductionmentioning

confidence: 99%

Defect Analysis of High Electron Mobility Diketopyrrolopyrrole Copolymers Made by Direct Arylation Polycondensation

et al. 2015

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Defect structures in high-performance conjugated polymers are generally known but still challenging to characterize on a quantitative basis. Here, we present a detailed analysis of backbone topology of a series of copolymers PDPPTh 2 F 4 having alternating dithienyldiketopyrrolopyrrole (DPPTh 2 ) and tetrafluorobenzene (F 4 ) units made by direct arylation polycondensation (DAP). In contrast to early expectations of unselective C−H activation during the DAP of monomers with multiple C−H bonds, detailed structure analysis by high-temperature 1 H NMR spectroscopy reveals welldefined and alternating backbones with a quantifiable amount of 0−12% DPPTh 2 homocouplings as the only defect structure in the main chain. Homocoupled −DPPTh 2 −DPPTh 2 − structural units are additionally characterized by UV−vis spectroscopy. While −DPPTh 2 −H end groups are inert to other side reactions, −F 4 −Br end groups are weakly susceptible to both dehalogenation and reaction with toluene. However, despite the presence of DPPTh 2 homocouplings, high field-effect transistor electron mobilities up to ∼0.6 cm 2 /(V s) are achieved. This study highlights both that DPPTh 2 homocouplings pose a prevalent structural defect in DPPTh 2 -based conjugated polymers made by DAP and that a very simple four-step DAP protocol can yield materials with varying molar mass and excellent n-type transistor performance.

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Section: Introductionmentioning

confidence: 99%

Defect Analysis of High Electron Mobility Diketopyrrolopyrrole Copolymers Made by Direct Arylation Polycondensation

et al. 2015

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“…Since the first publication by Farnum in 1974, the 1,4-diketopyrrolopyrrole (DPP) unit has been intensely studied and used as a pigment or dye in a variety of applications. , Indeed, many articles , report the use of different substituents on the aromatic cycles flanking the DPP core (Ar, see Figure ), such as nitro, tert -butyl, or nitrile group, and on different positions, such as meta or para of a benzene ring or the 4- or 5-positions of a thiophene. This strategy is efficient to modulate the optical properties and the structural organization in the solid state.…”

Section: Introductionmentioning

confidence: 99%

Thiocarbonyl Substitution in 1,4-Dithioketopyrrolopyrrole and Thienopyrroledithione Derivatives: An Experimental and Theoretical Study

et al. 2014

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A series of new 1,4-dithioketopyrrolopyrrole and thienopyrrolodithione derivatives have been synthesized and characterized by spectroscopy and electrochemistry measurements. The replacement of carbonyl by thiocarbonyl has a direct effect on the optical gap and on the ionization potential and electron affinity energies. For example, the optical gaps have been lowered by 0.5 eV, a fact that has been correctly predicted by density functional theory and time-dependent density functional theory calculations. A theoretical analysis on the stability of the new molecules is also presented.

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“…[19][20][21][22] Here we use the Monte Carlo method to study strongly confined supercooled ST2 water. Our results are consistent with the possibility that a liquid-liquid phase transition occurs for similar temperatures and pressures as for the bulk.…”

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confidence: 99%

Liquid−Liquid Phase Transition in Confined Water: A Monte Carlo Study

Meyer

Stanley

1999

J. Phys. Chem. B

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We report simulations of water confined between two parallel flat (hydrophobic) walls separated by 10.95 Å. Our results are consistent with the possibility of a liquid-liquid phase transition separating two phases of different densities. The low-density liquid phase displays tetrahedral "ice-like" local ordering, while the highdensity liquid phase shows indications of a hexagonal layer structure similar to the quasi-2D ice forms recently found in simulations using the TIP4P potential.Amorphous solid water displays two distinct phases, low density amorphous ice (LDA) and high density amorphous ice (HDA) that transform into each other via a first order phase transition. 1 Recently, it has been proposed that the transition line between these known phases can be extrapolated to higher temperatures into the metastable liquid region of the phase diagram, raising the intriguing possibility of the coexistence of two liquid phases and of the existence of a second critical point in the metastable liquid. 2 This "liquid-liquid phase transition" scenario has been supported by computer simulations with various effective interaction potentials, specifically with the ST2, 2,3 TIP4P, 2,4 and the SPC/E 5 potentials. Also, it has been shown that simple lattice models of water 6 as well as simplified spherically symmetric soft core potentials 7 and mean field approaches 8 can display a liquid-liquid-phase transition. Experimental evidence for the existence of the second critical point is difficult to obtain, since the strong nucleation tendency in the region of the phase diagram, where the second critical point might be found, makes it impossible to keep water in the liquid state. 9 It is not clear whether the liquid-liquid phase transition occurs also for strongly confined water. Water in confined systems plays an important role in many biological and geological systems, 10,11 and methods have been developed to experimentally test the behavior of molecularly thin water films confined between hydrophilic 12,13 as well as hydrophobic 14 and metal 15 surfaces. In some of these systems the freezing of water seems inhibited, 14,16 thus allowing one to study the phase diagram of water in regions not accessible for bulk water.Apart from a few recent studies, 17,18 computer simulations of confined water have mostly been done at ambient temperatures. [19][20][21][22] Here we use the Monte Carlo method to study strongly confined supercooled ST2 water. Our results are consistent with the possibility that a liquid-liquid phase transition occurs for similar temperatures and pressures as for the bulk. Further, we find that the anisotropy of the confined system plays a key role in determining the phase behavior. In constant density simulations, phase transition behavior can be found only for the lateral pressure P xy (parallel to the walls), not for the transverse pressure P z (perpendicular to the walls).Our system consists of N ) 216 water molecules interacting with each other via the ST2 potential, 23 and interacting with the walls via the...

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Diketopyrrolopyrrole (DPP) Pigments

Cited by 6 publications

References 38 publications

Defect Analysis of High Electron Mobility Diketopyrrolopyrrole Copolymers Made by Direct Arylation Polycondensation

Defect Analysis of High Electron Mobility Diketopyrrolopyrrole Copolymers Made by Direct Arylation Polycondensation

Thiocarbonyl Substitution in 1,4-Dithioketopyrrolopyrrole and Thienopyrroledithione Derivatives: An Experimental and Theoretical Study

Liquid−Liquid Phase Transition in Confined Water: A Monte Carlo Study

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