Freezing the Motion in Hydroxy-Functionalized Ionic Liquids-Temperature Dependent NMR Deuteron Quadrupole Coupling Constants for Two Types of Hydrogen Bonds Far below the Glass Transition

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Freezing the Motion in Hydroxy-Functionalized Ionic Liquids-Temperature Dependent NMR Deuteron Quadrupole Coupling Constants for Two Types of Hydrogen Bonds Far below the Glass Transition. / Khudozhitkov, Alexander E.; Niemann, Thomas; Stange, Peter et al.

In: The journal of physical chemistry letters, Vol. 11, No. 15, 06.08.2020, p. 6000-6006.

Research output: Contribution to journal › Article › peer-review

BibTeX

@article{bb7666c878bc4136a38b768014c807b8,

title = "Freezing the Motion in Hydroxy-Functionalized Ionic Liquids-Temperature Dependent NMR Deuteron Quadrupole Coupling Constants for Two Types of Hydrogen Bonds Far below the Glass Transition",

abstract = "We measured the deuteron quadrupole coupling constants (DQCCs) for hydroxy-functionalized ionic liquids (ILs) with varying alkyl chain length over the temperature range between 60 and 200 K by means of solid-state NMR spectroscopy. For all temperatures, the 2H spectra show two DQCCs representing different types of hydrogen bonds. Higher values, ranging from 220 to 250 kHz, indicate weaker hydrogen bonds between cation and anion (c-a), and lower values varying from 165 to 210 kHz result from stronger hydrogen bonds between the OD groups of cations (c-c), in agreement with recent observations in infrared, neutron diffraction, and NMR studies. We observed different temperature dependencies for (c-a) and (c-c) hydrogen bonding. From the static pattern of the 2H spectra at the lowest temperatures, we derived the true DQCCs being up to 20 kHz larger than recently reported values measured at the glass transition temperature. We were able to freeze the librational motions of the hydrogen bonds in the ILs. The temperature dependence of the (c-a) and (c-c) cluster populations in the glassy state is opposite to that observed in the liquid state, partly anticipating the behavior of ILs tending to crystallize.",

keywords = "NUCLEAR-MAGNETIC-RESONANCE, CATIONIC CLUSTERS, CHARGED IONS, PROTON, ELECTROLYTES, EXTRACTION, CRYSTALS, TIME, ICE",

author = "Khudozhitkov, {Alexander E.} and Thomas Niemann and Peter Stange and Masaki Donoshita and Stepanov, {Alexander G.} and Hiroshi Kitagawa and Kolokolov, {Daniil I.} and Ralf Ludwig",

year = "2020",

month = aug,

day = "6",

doi = "10.1021/acs.jpclett.0c01731",

language = "English",

volume = "11",

pages = "6000--6006",

journal = "Journal of Physical Chemistry Letters",

issn = "1948-7185",

publisher = "American Chemical Society",

number = "15",

}

RIS

TY - JOUR

T1 - Freezing the Motion in Hydroxy-Functionalized Ionic Liquids-Temperature Dependent NMR Deuteron Quadrupole Coupling Constants for Two Types of Hydrogen Bonds Far below the Glass Transition

AU - Khudozhitkov, Alexander E.

AU - Niemann, Thomas

AU - Stange, Peter

AU - Donoshita, Masaki

AU - Stepanov, Alexander G.

AU - Kitagawa, Hiroshi

AU - Kolokolov, Daniil I.

AU - Ludwig, Ralf

PY - 2020/8/6

Y1 - 2020/8/6

N2 - We measured the deuteron quadrupole coupling constants (DQCCs) for hydroxy-functionalized ionic liquids (ILs) with varying alkyl chain length over the temperature range between 60 and 200 K by means of solid-state NMR spectroscopy. For all temperatures, the 2H spectra show two DQCCs representing different types of hydrogen bonds. Higher values, ranging from 220 to 250 kHz, indicate weaker hydrogen bonds between cation and anion (c-a), and lower values varying from 165 to 210 kHz result from stronger hydrogen bonds between the OD groups of cations (c-c), in agreement with recent observations in infrared, neutron diffraction, and NMR studies. We observed different temperature dependencies for (c-a) and (c-c) hydrogen bonding. From the static pattern of the 2H spectra at the lowest temperatures, we derived the true DQCCs being up to 20 kHz larger than recently reported values measured at the glass transition temperature. We were able to freeze the librational motions of the hydrogen bonds in the ILs. The temperature dependence of the (c-a) and (c-c) cluster populations in the glassy state is opposite to that observed in the liquid state, partly anticipating the behavior of ILs tending to crystallize.

AB - We measured the deuteron quadrupole coupling constants (DQCCs) for hydroxy-functionalized ionic liquids (ILs) with varying alkyl chain length over the temperature range between 60 and 200 K by means of solid-state NMR spectroscopy. For all temperatures, the 2H spectra show two DQCCs representing different types of hydrogen bonds. Higher values, ranging from 220 to 250 kHz, indicate weaker hydrogen bonds between cation and anion (c-a), and lower values varying from 165 to 210 kHz result from stronger hydrogen bonds between the OD groups of cations (c-c), in agreement with recent observations in infrared, neutron diffraction, and NMR studies. We observed different temperature dependencies for (c-a) and (c-c) hydrogen bonding. From the static pattern of the 2H spectra at the lowest temperatures, we derived the true DQCCs being up to 20 kHz larger than recently reported values measured at the glass transition temperature. We were able to freeze the librational motions of the hydrogen bonds in the ILs. The temperature dependence of the (c-a) and (c-c) cluster populations in the glassy state is opposite to that observed in the liquid state, partly anticipating the behavior of ILs tending to crystallize.

KW - NUCLEAR-MAGNETIC-RESONANCE

KW - CATIONIC CLUSTERS

KW - CHARGED IONS

KW - PROTON

KW - ELECTROLYTES

KW - EXTRACTION

KW - CRYSTALS

KW - TIME

KW - ICE

UR - http://www.scopus.com/inward/record.url?scp=85089613886&partnerID=8YFLogxK

U2 - 10.1021/acs.jpclett.0c01731

DO - 10.1021/acs.jpclett.0c01731

M3 - Article

C2 - 32640795

AN - SCOPUS:85089613886

VL - 11

SP - 6000

EP - 6006

JO - Journal of Physical Chemistry Letters

JF - Journal of Physical Chemistry Letters

SN - 1948-7185

IS - 15

ER -

ID: 24985502