Raman spectra and non-empirical calculations of dimethylformamide molecular clusters structure

Hushvaktov, H.; Jumabaev, А.; Doroshenko, I.; Absanov, А.

doi:10.1016/j.vibspec.2021.103315

Cited by 15 publications

(8 citation statements)

References 24 publications

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“…Accordingly, Raman spectra exhibit signals from only three components: DMF, FSI – , and minor contributions were from PVDF-HFP. DMF and FSI – spectra agree with literature data , and our DFT modeling as shown below, while PVDF-HFP related peaks are found in the region 780–820 cm –1 , corresponding to C–F side-chain stretching modes …”

Section: Resultssupporting

confidence: 89%

“…35 Accordingly, Raman spectra exhibit signals from only three components: DMF, FSI − , and minor contributions were from PVDF-HFP. DMF and FSI − spectra agree with literature data 36,37 and our DFT modeling as shown below, while PVDF-HFP related peaks are found in the region 780−820 cm −1 , corresponding to C−F side-chain stretching modes. 38 The first step was to use Raman spectroscopy to determine the actual molar ratio of FSI − to DMF in the membrane after it had dried, as reported in Figure 3b.…”

Section: Quantitative Investigation Of Polymer−solvent− Salt Interact...supporting

confidence: 89%

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Host–Guest Interactions and Transport Mechanism in Poly(vinylidene fluoride)-Based Quasi-Solid Electrolytes for Lithium Metal Batteries

Vallana,

Carena,

Ceribelli

et al. 2024

ACS Appl. Energy Mater.

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All-solid-state lithium metal batteries (SS-LMBs) are expected to meet the strong requirements of the automotive sector in terms of performance and safety. Among the different solid electrolytes, poly(vinylidene fluoride) (PVDF)-based systems offer good performance in terms of ionic conductivity and stability at the anodic interface. However, despite the high polymer permittivity (ε′ ≈ 10−11) which should allow efficient salt dissociation, there is growing evidence that the ionic transport requires the presence of a non-negligible amount of residual, or permanent, solvent in the membrane. In this paper, we study the Li + transport mechanism in a model system consisting of poly(vinylidene fluoride-cohexafluoropropylene) (PFDF-HFP), lithium bis(fluorosulfonyl)imide (LiFSI) salt, and dimethylformamide (DMF) as permanent solvent, combining a large set of experimental techniques (thermal analysis, NMR, IR and Raman spectroscopy, impedance spectroscopy) and accurate density functional theory (DFT) modeling. We show that Li + −DMF interactions are predominant in these quasi-solid electrolytes (QSEs) and are the basis of the effective ion transport mechanism. Permanent solvent amounts on the order of [DMF]/[Li + ] ∼ 2−3 are required to make QSEs able to practically work in a real environment.

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Section: Resultssupporting

confidence: 89%

Section: Quantitative Investigation Of Polymer−solvent− Salt Interact...supporting

confidence: 89%

Host–Guest Interactions and Transport Mechanism in Poly(vinylidene fluoride)-Based Quasi-Solid Electrolytes for Lithium Metal Batteries

Vallana,

Carena,

Ceribelli

et al. 2024

ACS Appl. Energy Mater.

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“…This reaction behavior should be indicated in the changes of OH stretches in the 3300–4000 cm −1 range [ 17 ] (Figure 1f). Based on two previous investigations of Raman [ 18 ] and density functional theory (DFT) simulation [ 19 ] for N , N ‐dimethylformamide (DMF), no peaks corresponding to DMF are expected in this range. In ALHP‐C, a small quantity of water was present, as indicated by the peaks υ 1 and υ 2 at 3540 and 3476 cm −1 , respectively, with an absorbance of ≈4.0 × 10 −2 (Figure S4c, Supporting Information), based on the OH stretches for pure water (υ 1 at 3570 cm −1 (bonding length ( d ): 0.30 nm), the υ 2 at ≈3440 cm −1 ( d : 0.29 nm), υ 3 at 3322 cm −1 ( d : 0.28 nm), and OH vibrations of tetrahedral H 2 O at 3250 cm −1[ 17,20 ] ).…”

Section: Resultsmentioning

confidence: 99%

Stabilization of the Alkylammonium Cations in Halide Perovskite Thin Films by Water‐Mediated Proton Transfer

et al. 2023

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has attracted much research attention, more fundamental studies are required to achieve viable and stable ALHPs.The deprotonation of alkylammonium can cause the instability of ALHP crystal growth according to several studies of proton defects in the alkylammonium of ALHP. Zhang et al. reported that the thermodynamic instability of ALHP arises due to hydrogen vacancies in the crystal, as found by density functional theory calculations. [4] Cardenas-Daw et al. [5] have reported crystal phase destabilization by the undesired formation of methylamine (MA) from methylammonium (MA + ) in MAPbI 3 crystals. Doherty et al. [6] solved the destabilization issue by adding ethylenediaminetetraacetic acid into the perovskite precursor, which protonated the alkylammonium (A-site) molecule, resulting in stabilizing ALHP crystal growth. However, the specific mechanisms and relations between the protonation of the alkylammonium molecule and the stabilization of the ALHP crystal structure were not discussed.Meanwhile, halide-induced protonation can be considered to obtain the stable perovskite phase, according to a report from Bajaj et al. [7] They highlighted the important role of I −mediated hydrogen (H) bonding rearrangement of H 2 O in the iodide-dihydrate complex. In a similar principle, halideinduced protonation can occur with the H 2 O in the perovskite The development of alkylammonium lead trihalide perovskite (ALHP) photovoltaics has grown rapidly over the past decade. However, there are remaining critical challenges, such as proton defects, which can lead to the material instability of ALHPs. Although specific strategies, including the use of halide additives, have significantly reduced the defects, a fundamental understanding of the defect passivation mechanism remains elusive. Herein, an approach and mechanism for minimizing proton defects in ALHP crystals by adding ionized halides to the perovskite precursor solution are reported. This work clarifies that the ionized halides induced proton transfer from H 2 O to the alkylammonium cation in the precursor solution, stabilizing the ALHP crystals. The fundamental characteristics of ALHP and its precursors are examined by X-ray diffraction, transmittance electron microscopy, in situ extended X-ray absorption fine structure, Fourier transform NMR spectroscopy, and Fourier transform infrared spectroscopy. The findings from this work will guide the development of highly stable ALHP crystals, enabling efficient and stable optoelectronic ALHP devices.

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“…Now, it has been established that noncovalent interactions, in particular hydrogen bonding, play an important role in atmospheric chemistry, astrophysics, as well as many biochemical and catalytic processes [1][2][3]. 1,2-butadione or biacetyl are other names for diacetyl (DA) [4][5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

Study of diacetyl-water clusters using Raman scattering and theoretical calculations

Jumabaev¹,

Hushvaktov²,

Absanov³

et al. 2022

УФЖ

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In this work, the intermolecular interactions of diacetyl and water molecules were studied using the vibration spectrum. The Raman scattering spectra obtained in the range of 500– 2000 cm−1 were analyzed and compared with the results of calculations. For the first time аlso, the charge density distribution and 3D potential energy graphs are examined using simulations for diacetyl molecules. With the increase in the number of molecules at the formation of molecular clusters with the water molecule, the saturation of the intermolecular interaction energy corresponding to a single Н-bond is observed. This corresponds to DA+(Н2O)3 molecular clusters and allows one to conclude that this cluster is stable relative to the others.

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Raman spectra and non-empirical calculations of dimethylformamide molecular clusters structure

Cited by 15 publications

References 24 publications

Host–Guest Interactions and Transport Mechanism in Poly(vinylidene fluoride)-Based Quasi-Solid Electrolytes for Lithium Metal Batteries

Host–Guest Interactions and Transport Mechanism in Poly(vinylidene fluoride)-Based Quasi-Solid Electrolytes for Lithium Metal Batteries

Stabilization of the Alkylammonium Cations in Halide Perovskite Thin Films by Water‐Mediated Proton Transfer

Study of diacetyl-water clusters using Raman scattering and theoretical calculations

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