Unraveling the Anomalous Solvatochromic Response of the Formate Ion Vibrational Spectrum: An Infrared, Ar-Tagging Study of the HCO2¯, DCO2¯, and HCO2¯·H2O Ions

Gerardi, Helen K.; DeBlase, Andrew F.; Su, Xiaoge; Jordan, Kenneth D.; McCoy, Anne B.; Johnson, Mark A.

doi:10.1021/jz200937v

Cited by 52 publications

(72 citation statements)

References 25 publications

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“…23 HCO − 2 ·H 2 O exhibits the same Franck-Condon-like progression as the other clusters in addition to a broad background (see supplementary material of Ref. 26 and Fig. 8(c)), the latter of which, however, being less pronounced as compared to complexes with either CH 3 NO − 2 or CH 3 CO − 2 .…”

Section: Introductionmentioning

confidence: 61%

“…8(c)). 26 It corresponds to a coherent wave-packet motion along Q 1 after excitation of the OH-stretch state. Above 3350 cm −1 , which roughly coincides with the curve crossing between the two OH-stretch PESs (Fig.…”

Section: Absorption Spectrummentioning

confidence: 99%

“…Johnson et al 18,[23][24][25][26] did not measure the absorption spectrum [Eq. (17)] directly, but an Ar-"tag" spectrum.…”

Section: Ar-tag Spectrummentioning

confidence: 99%

“…18,[23][24][25][26] In addition in related work, Neumark and coworkers have studied the complex with NO − 3 . 27 Despite the fact that these complexes show all the nontrivial features of the IR spectroscopy of hydrogen bonds, their spectral signatures are particularly simple.…”

Section: Introductionmentioning

confidence: 99%

“…26 We chose that particular complex because of its smallness and its high C 2v symmetry. NO − 2 ·H 2 O, which would be even smaller, has been discarded since its C 2v structure is not the lowest energy structure.…”

Section: Introductionmentioning

confidence: 99%

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Nonadiabatic vibrational dynamics in the HCO2−⋅H2O complex

Hamm

Stock

2015

The Journal of Chemical Physics

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Based on extensive ab initio calculations and the time-propagation of the nuclear Schrödinger equation, we study the vibrational relaxation dynamics and resulting spectral signatures of the OH stretch vibration of a hydrogen-bonded complex, HCO − 2 H 2 O. Despite their smallness, it has been shown experimentally by Johnson and coworkers that the gas-phase infrared spectra of these types of complexes exhibit much of the complexity commonly observed for hydrogen-bonded systems. That is, the OH stretch band exhibits a significant red shift together with an extreme broadening and a pronounced substructure, which reflects its very strong anharmonicity. Employing an adiabatic separation of time scales between the three intramolecular high-frequency modes of the water molecule and the three most important intermolecular low-frequency modes of the complex, we calculate potential energy surfaces (PESs) of the ground and the first excited states of the high-frequency modes and identify a vibrational conical intersection between the PESs of the OH stretch fundamental and the HOH bend overtone. By performing a time-dependent propagation of the resulting system, we show that the conical intersection affects a coherent population transfer between the two states, the first step of which being ultrafast (60 fs) and irreversible. The subsequent relaxation of vibrational energy into the HOH bend and ground state occurs incoherently but also quite fast (1 ps), although the corresponding PESs are well separated in energy. Owing to the smaller effective mass difference between light and heavy degrees of freedom, the adiabatic ansatz is consequently less significant for vibrations than in the electronic case. Based on the model, we consider several approximations to calculate the measured Ar-tag action spectrum of HCO − 2 H 2 O and achieve semiquantitative agreement with the experiment. Based on extensive ab initio calculations and the time-propagation of the nuclear Schrödinger equation, we study the vibrational relaxation dynamics and resulting spectral signatures of the OH stretch vibration of a hydrogen-bonded complex, HCO − 2 · H 2 O. Despite their smallness, it has been shown experimentally by Johnson and coworkers that the gas-phase infrared spectra of these types of complexes exhibit much of the complexity commonly observed for hydrogen-bonded systems. That is, the OH stretch band exhibits a significant red shift together with an extreme broadening and a pronounced substructure, which reflects its very strong anharmonicity. Employing an adiabatic separation of time scales between the three intramolecular high-frequency modes of the water molecule and the three most important intermolecular low-frequency modes of the complex, we calculate potential energy surfaces (PESs) of the ground and the first excited states of the high-frequency modes and identify a vibrational conical intersection between the PESs of the OH stretch fundamental and the HOH bend overtone. By performing a time-dependent propagation of the resulti...

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Section: Introductionmentioning

confidence: 61%

Section: Absorption Spectrummentioning

confidence: 99%

“…Johnson et al 18,[23][24][25][26] did not measure the absorption spectrum [Eq. (17)] directly, but an Ar-"tag" spectrum.…”

Section: Ar-tag Spectrummentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Nonadiabatic vibrational dynamics in the HCO2−⋅H2O complex

Hamm

Stock

2015

The Journal of Chemical Physics

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Ground‐State Structure of the Proton‐Bound Formate Dimer by Cold‐Ion Infrared Action Spectroscopy

et al. 2018

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The proton‐bound dicarboxylate motif, RCOO−⋅H+⋅−OOCR, is a prevalent chemical configuration found in many condensed‐phase systems. The proton‐bound formate dimer HCOO−⋅H+⋅−OOCH was studied utilizing cold‐ion IR action spectroscopy in the range 400–1800 cm−1. The spectrum obtained at ca. 0.4 K of ions captured in He nanodroplets was compared to that measured at ca. 10 K by photodissociation of Ar‐ion complexes. Similar band patterns are obtained by the two techniques that are consistent with calculations for a C2 symmetry structure with a proton shared equally between the two formate moieties. Isotopic substitution experiments point to the nominal parallel stretch of the bridging proton appearing as a sharp, dominant feature near 600 cm−1. Multidimensional anharmonic calculations reveal that the bridging proton motion is strongly coupled to the flanking −COO− framework, an effect that is in line with the expected change in −C=O bond rehybridization upon protonation.

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Ground‐State Structure of the Proton‐Bound Formate Dimer by Cold‐Ion Infrared Action Spectroscopy

et al. 2018

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The proton-bound dicarboxylate motif, RCOO ⋅H ⋅ OOCR, is a prevalent chemical configuration found in many condensed-phase systems. The proton-bound formate dimer HCOO ⋅H ⋅ OOCH was studied utilizing cold-ion IR action spectroscopy in the range 400-1800 cm . The spectrum obtained at ca. 0.4 K of ions captured in He nanodroplets was compared to that measured at ca. 10 K by photodissociation of Ar-ion complexes. Similar band patterns are obtained by the two techniques that are consistent with calculations for a C symmetry structure with a proton shared equally between the two formate moieties. Isotopic substitution experiments point to the nominal parallel stretch of the bridging proton appearing as a sharp, dominant feature near 600 cm . Multidimensional anharmonic calculations reveal that the bridging proton motion is strongly coupled to the flanking -COO framework, an effect that is in line with the expected change in -C=O bond rehybridization upon protonation.

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Unraveling the Anomalous Solvatochromic Response of the Formate Ion Vibrational Spectrum: An Infrared, Ar-Tagging Study of the HCO₂^¯, DCO₂^¯, and HCO₂^¯·H₂O Ions

Cited by 52 publications

References 25 publications

Nonadiabatic vibrational dynamics in the HCO2−⋅H2O complex

Nonadiabatic vibrational dynamics in the HCO2−⋅H2O complex

Ground‐State Structure of the Proton‐Bound Formate Dimer by Cold‐Ion Infrared Action Spectroscopy

Ground‐State Structure of the Proton‐Bound Formate Dimer by Cold‐Ion Infrared Action Spectroscopy

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