Unraveling the role of microenvironment and hydrodynamic forces on the vibrational relaxation rates of pyridine–water complexes

Kalampounias, Angelos G.; Tsilomelekis, George; Boghosian, Soghomon

doi:10.1016/j.molliq.2014.07.020

“…However, Bakó et al have observed that an accurate estimation of both interaction distances and coordination number for the N

\dots

O contacts is very difficult as a consequence of the concomitant presence of the inter‐molecular H‐bond (1.8–1.9 Å) between solvent molecules. Lower values for the number of hydrogen bonds between the heterocyclic nitrogen atom and the hydrogen atom of solvent (in the range 1–2) are obtained by both experiments and models to interpret experimental findings, with a preponderance of 1:1 complexes …”

Section: Resultsmentioning

confidence: 90%

“…Pyridine in aqueous solution interacts with water essentially by forming hydrogen bonds, which involve the lone pair on the nitrogen atom of the heterocyclic compound with solvent . To validate the proposed model, in which the lone pair on nitrogen atom is explicitly described through the VS, the H‐bond interactions have been compared with a model without VS (hereafter NO_VS) and previous experimental and computational results. The first information on the hydrogen bond structure has been obtained by determining the radial pair distribution function, g(r), for the N

\dots

H and N

\dots

O contacts, reported in Figure .…”

Section: Resultsmentioning

confidence: 99%

Electronic absorption spectra of pyridine and nicotine in aqueous solution with a combined molecular dynamics and polarizable QM/MM approach

Pagliai

¹

,

Mancini

²

,

Carnimeo

³

et al. 2016

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The electronic absorption spectra of pyridine and nicotine in aqueous solution have been computed using a multistep approach. The computational protocol consists in studying the solute solvation with accurate molecular dynamics simulations, characterizing the hydrogen bond interactions, and calculating electronic transitions for a series of configurations extracted from the molecular dynamics trajectories with a polarizable QM/MM scheme based on the fluctuating charge model. Molecular dynamics simulations and electronic transition calculations have been performed on both pyridine and nicotine. Furthermore, the contributions of solute vibrational effect on electronic absorption spectra have been taken into account in the so called vertical gradient approximation.

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“…It is worth mentioning here that contrary to the well defined, Gaussian-type predicted peaks by the model, in our ATR-FTIR spectra the first harmonic appears to be a convolution of more than one contributions in the overall spectral envelope. To address this, all the spectra were deconvoluted using Gauss functions based on the Levenberg-Marquardt algorithm as shown elsewhere 24,25,26,27 . The deconvoluted spectra show two or three major peaks separated by approximately 800 cm -1 .…”

Section: Resultsmentioning

confidence: 99%

Rational Design of Gold Nanostars with Tailorable Plasmonic Properties

Tsoulos

¹

,

Atta²,

Lagos³

et al. 2018

Preprint

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<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

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“…To address this issue, all the spectra were deconvoluted using Gauss functions based on the Levenberg-Marquardt algorithm as shown elsewhere. [21][22][23][24] The deconvoluted spectra show two or three major peaks separated by approximately 800 cm -1 . To further investigate the latter, in Figure 4b and 4c we report the comparison between the deconvoluted ATR-FTIR spectrum and the calculated absorption cross section for 90 nm-spike nanostars.…”

Section: Resultsmentioning

confidence: 99%

Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

Tsoulos¹,

Atta²,

Lagos³

et al. 2019

Preprint

1

0

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<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

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Unraveling the role of microenvironment and hydrodynamic forces on the vibrational relaxation rates of pyridine–water complexes

Cited by 16 publications

References 32 publications

Electronic absorption spectra of pyridine and nicotine in aqueous solution with a combined molecular dynamics and polarizable QM/MM approach

Electronic absorption spectra of pyridine and nicotine in aqueous solution with a combined molecular dynamics and polarizable QM/MM approach

Rational Design of Gold Nanostars with Tailorable Plasmonic Properties

Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

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