Vibrational dynamics and solvatochromism of the label SCN in various solvents and hemoglobin by time dependent IR and 2D-IR spectroscopy

Wilderen, Luuk J. G. W. van; Kern-Michler, Daniela; Müller‐Werkmeister, Henrike M.; Bredenbeck, Jens

doi:10.1039/c4cp01498g

Cited by 100 publications

(127 citation statements)

References 70 publications

(105 reference statements)

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“…A recent study by van Wilderen et al also showed that MeSCN exhibits a solvent-independent anharmonicity, 61 though the connection with bond polarization was not made. While the anharmonicity may be constant for carbonyls in solvents such as hexanes, DMSO, and D 2 O, there is always some contribution from nonlinear and higher-order Stark effects to vibrational frequency shifts, though their contribution may be small.…”

Section: Discussionmentioning

confidence: 99%

Solvent-Independent Anharmonicity for Carbonyl Oscillators

et al. 2017

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The physical origins of vibrational frequency shifts have been extensively studied in order to understand noncovalent intermolecular interactions in the condensed phase. In the case of carbonyls, vibrational solvatochromism, MD simulations, and vibrational Stark spectroscopy suggest that the frequency shifts observed in simple solvents arise predominately from the environment’s electric field due to the vibrational Stark effect. This is contrary to many previously invoked descriptions of vibrational frequency shifts, such as bond polarization, whereby the bond’s force constant and/or partial nuclear charges are altered due to the environment, often illustrated in terms of favored resonance structures. Here we test these hypotheses using vibrational solvatochromism as measured using 2D IR to assess the solvent dependence of the bond anharmonicity. These results indicate that the carbonyl bond’s anharmonicity is independent of solvent as tested using hexanes, DMSO, and D2O and is supported by simulated 2D spectra. In support of the linear vibrational Stark effect, these 2D IR measurements are consistent with the assertion that the Stark tuning rate is unperturbed by the electric field generated by both hydrogen and non-hydrogen bonding environments and further extends the general applicability of carbonyl probes for studying intermolecular interactions.

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Section: Discussionmentioning

confidence: 99%

Solvent-Independent Anharmonicity for Carbonyl Oscillators

et al. 2017

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“…64,65 Such probes will extend the observation time window. Independent of that, the azide group is attractive also because of the simple routes it enables to chemically modify the resulting MLs by using straightforward "click"-chemistry.…”

Section: Resultsmentioning

confidence: 99%

2D attenuated total reflectance infrared spectroscopy reveals ultrafast vibrational dynamics of organic monolayers at metal-liquid interfaces

Kraack

Lotti

Hamm

2015

The Journal of Chemical Physics

101

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We present two-dimensional infrared (2D IR) spectra of organic monolayers immobilized on thin metallic films at the solid liquid interface. The experiments are acquired under Attenuated Total Reflectance (ATR) conditions which allow a surface-sensitive measurement of spectral diffusion, sample inhomogeneity, and vibrational relaxation of the monolayers. Terminal azide functional groups are used as local probes of the environment and structural dynamics of the samples. Specifically, we investigate the influence of different alkyl chain-lengths on the ultrafast dynamics of the monolayer, revealing a smaller initial inhomogeneity and faster spectral diffusion with increasing chain-length. Furthermore, by varying the environment (i.e., in different solvents or as bare sample), we conclude that the most significant contribution to spectral diffusion stems from intra-and intermolecular dynamics within the monolayer. The obtained results demonstrate that 2D ATR IR spectroscopy is a versatile tool for measuring interfacial dynamics of adsorbed molecules. We present two-dimensional infrared (2D IR) spectra of organic monolayers immobilized on thin metallic films at the solid liquid interface. The experiments are acquired under Attenuated Total Reflectance (ATR) conditions which allow a surface-sensitive measurement of spectral diffusion, sample inhomogeneity, and vibrational relaxation of the monolayers. Terminal azide functional groups are used as local probes of the environment and structural dynamics of the samples. Specifically, we investigate the influence of different alkyl chain-lengths on the ultrafast dynamics of the monolayer, revealing a smaller initial inhomogeneity and faster spectral diffusion with increasing chain-length. Furthermore, by varying the environment (i.e., in different solvents or as bare sample), we conclude that the most significant contribution to spectral diffusion stems from intra-and intermolecular dynamics within the monolayer. The obtained results demonstrate that 2D ATR IR spectroscopy is a versatile tool for measuring interfacial dynamics of adsorbed molecules. C 2015 AIP Publishing LLC. [http://dx

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“…In principle, 2D IR spectroscopy can be applied to characterize any site in any protein by selective labeling of side chains via incorporation of unnatural amino acids functionalized with spectrally resolved vibrational probes, such as cyano (CN), 50, 94–96 thiocyanate (SCN), 97 and azido (Az) 93, 98 functional groups. A variety of routes exist for their site-selective incorporation into proteins.…”

Section: Peptide and Protein Structure And Dynamicsmentioning

confidence: 99%