Conformational study of a single molecule of poly <i>para</i> phenylene ethynylenes in dilute solutions

Maskey, Sabina; Pierce, Flint; Perahia, Dvora; Grest, Gary S.

doi:10.1063/1.3604820

Cited by 19 publications

(32 citation statements)

References 18 publications

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“…The parameters were taken from Refs. [32,33] in which PCFF (polymer consistent force field) force field parameters were converted to OPLS form. Modification for torsional potential parameters of the phenylene rings as evaluated in Ref.…”

Section: Methodsmentioning

confidence: 99%

“…P θ > 0 describes a co-planar alignment of aromatic rings, while P θ < 0 indicates perpendicular alignments. P θ = 0 and P θ = 1 refer to completely random and fully co-planar alignment of the rings, respectively [32,33]. Figure 3 shows the order parameter versus Δn for 10-PPE with nonyl side chains in toluene and water after 7.7 ns MD simulations in the NpT ensemble.…”

Section: Structural Properties Of Solvated 25-dinonyl-10-ppementioning

confidence: 99%

“…Water is a poor solvent for both the backbone and the side chains while toluene is a good solvent for the backbone and a poor solvent for the side chains [32,33]. Figure 2 shows the structure of 10-PPE (a) in toluene and (b) in water at 7.7 ns in the NpT ensemble.…”

Section: Structural Properties Of Solvated 25-dinonyl-10-ppementioning

confidence: 99%

“…The European Physical Journal Special Topics Structural studies using small angle neutron scattering (SANS) have shown that dialkyl PPE forms a molecular solution with an extended backbone at high temperature and low concentrations [32,69]. In water (Fig.…”

Section: Structural Properties Of Solvated 25-dinonyl-10-ppementioning

confidence: 99%

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Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on many-body Green's functions theory

Bagheri

Karttunen

Baumeier

2016

Eur. Phys. J. Spec. Top.

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Abstract. Electronic excitations in dilute solutions of poly para phenylene ethynylene (poly-PPE) are studied using a QM/MM approach combining many-body Green's functions theory within the GW approximation and the Bethe-Salpeter equation with polarizable force field models. Oligomers up to a length of 7.5 nm (10 repeat units) functionalized with nonyl side chains are solvated in toluene and water, respectively. After equilibration using atomistic molecular dynamics (MD), the system is partitioned into a quantum region (backbone) embedded into a classical (side chains and solvent) environment. Optical absorption properties are calculated solving the coupled QM/MM system self-consistently and special attention is paid to the effects of solvents. The model allows to differentiate the influence of oligomer conformation induced by the solvation from electronic effects related to local electric fields and polarization. It is found that the electronic environment contributions are negligible compared to the conformational dynamics of the conjugated PPE. An analysis of the electron-hole wave function reveals a sensitivity of energy and localization characteristics of the excited states to bends in the global conformation of the oligomer rather than to the relative of phenyl rings along the backbone.

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Section: Methodsmentioning

confidence: 99%

Section: Structural Properties Of Solvated 25-dinonyl-10-ppementioning

confidence: 99%

Section: Structural Properties Of Solvated 25-dinonyl-10-ppementioning

confidence: 99%

Section: Structural Properties Of Solvated 25-dinonyl-10-ppementioning

confidence: 99%

See 2 more Smart Citations

Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on many-body Green's functions theory

Bagheri

Karttunen

Baumeier

2016

Eur. Phys. J. Spec. Top.

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“…Perahia et al have shown that dinonyl PPE in toluene, at high temperatures and low concentrations form a molecular solution with relatively extended chains while at lower temperatures and higher concentrations, they assemble into aggregates that eventually form a gel. The effect of molecular parameters such as polymer molecular weight and the length of the side chains on PPE conformation in different solvents were studied by Maskey et al They reported that PPE molecules assume extended configuration independent of solvent quality or the nature of the side chains. The relationship between the conjugated polymer conformation and their optical properties such as absorption and emission has been studied by numerous research works, both in solution and in thin films and shown that the chemical structure determines the configuration.…”

Section: Introductionmentioning

confidence: 99%

Conformation of ionizable poly Para phenylene ethynylene in dilute solutions

Wijesinghe

Maskey

Perahia

et al. 2015

J. Polym. Sci. Part B: Polym. Phys.

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The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality have been studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro-optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro-optical properties which are critical in current and potential uses. This study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonyl PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent, whereas in water and implicit poor solvent, the nonyl side chains are collapsed toward the PPE backbone. Rotation around the aromatic ring is fast and no long range correlations are seen within the backbone.

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Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level

Zhao¹,

Liu

Ran³

et al. 2017

J Mol Model

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Comb-like polycarboxylate ether (PCE) molecules with different content of methyl groups substituted on backbone and different location of methyl groups substituted on the side chains, respectively, were designed and were studied in explicit salt solutions by all-atom molecular dynamics simulations. Methyl groups substituted on the backbone of PCE have a great effect on the conformation of PCE. Stiffness of charged backbone was not only affected by the rotational freedom but also the electrostatic repulsion between the charged COO groups. The interaction of counterions (Na) with COO groups for PCE3 (with part of AA substituted by MAA on the backbone) was stronger and the screen effect was great, which decided the smaller size of PCE3. The interaction between water and COO groups was strong regardless of the content of AA substituted by MAA on the backbone. The effect of methyl groups substituted on the different location of side chains on the conformation of PCE was less than that of methyl groups substituted on the backbone. The equilibrium sizes of the four PCE molecules with methyl groups substituted on the side chains were similar. Graphical Abstract Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level.

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Conformational study of a single molecule of poly para phenylene ethynylenes in dilute solutions

Cited by 19 publications

References 18 publications

Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on many-body Green's functions theory

Solvent effects on optical excitations of poly para phenylene ethynylene studied by QM/MM simulations based on many-body Green's functions theory

Conformation of ionizable poly Para phenylene ethynylene in dilute solutions

Effect of methyl groups on conformational properties of small ionized comb-like polyelectrolytes at the atomic level

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