Energetic multi-component molecular solids of tetrafluoroterephthalic acid with some aza compounds by strong hydrogen bonds and weak intermolecular interactions of C–H⋯F and C–H⋯O

Wang, Lei; Hu, Yanjing; Wang, Wenqiang; Liu, Fa‐Qian; Huang, Keke

doi:10.1039/c4ce00133h

Cited by 40 publications

(5 citation statements)

References 53 publications

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“…This is equivalent to rotation of the tensor between the two frames of reference. A straightforward way to do that is to decompose each component of the Cartesian Raman tensor, α ij ( i , j = x , y , z ), into the sum of irreducible spherical tensors, α m k , where k = 0, 1, 2 and m = − k , − k + 1, ..., 0, ..., k – 1, k . We then make use of the crystal symmetry of MoS 2 and simple transformation properties of irreducible spherical tensors to get the spherical tensors in the laboratory-fixed coordinate system (see details in the Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Polarized Raman Reveals Alignment of Few-Layer MoS₂ Films

et al. 2019

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Ongoing interest in two-dimensional (2D) layered materials has motivated extensive studies of transitional metal dichalcogenides, especially its most pronounced representative, MoS 2 . The few-layer MoS 2 exhibits distinct properties from those in bulk, which predetermine its potential usage in optoelectronics and flexible devices. Recently, it was found that the layer orientation in MoS 2 thin films is a key parameter for their utilization in specific devices. Thus far, the alignment of MoS 2 layers has been detected mostly by transmission electron microscopy (TEM). The drawback of this method is that it requires elaborate sample preparation and probes only a nanometer-scale area of the sample surface. Here we present polarized Raman spectroscopy which provides information about the MoS 2 layer orientation on the area a few orders larger than in TEM. We show that the depolarization ratio of the significant Raman peaks A 1g and E 2g show specific values for the vertical and horizontal alignment of the MoS 2 layers. We also analytically calculated the depolarization ratio for a thin MoS 2 layer, which is in good agreement with the measured values. Polarized Raman spectroscopy thus provides a simple, reliable, and general way for specifying the layer alignment in various 2D layered materials.

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Section: Resultsmentioning

confidence: 99%

Polarized Raman Reveals Alignment of Few-Layer MoS₂ Films

et al. 2019

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“…As function is always related to three-dimensional structure, the quest for supramolecular synthons in three-dimensional networks is one of the main aims of crystal engineers to understand and explore the principles involved in the formation of that particular structure. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The acquired knowledge can then be used for the deliberate design of novel crystalline materials with desired properties. [21][22][23][24][25][26] For this purpose, however, highly consistent synthons with sufficiently directional intermolecular forces are required.…”

Section: Introductionmentioning

confidence: 99%

Robustness of thioamide dimer synthon, carbon bonding and thioamide–thioamide stacking in ferrocene-based thiosemicarbazones

et al. 2015

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“…On this basis, three CSD searches for CIC, BMIC and 6-methylisocytosine (MIC), which were restricted to organic compounds with determined three-dimensional coordinates and including either the 1H-or 3H-tautomeric form, were performed and yielded only 12 unique structures of MIC. These results can be divided into three salts [CSD refcode XOWKOK (Oueslati et al, 2009), YOCZUN (Wang et al, 2014) and EXIPOR (Kaabi et al, 2011)], two entries that contain solely the 1H-tautomer [FETSEC (Lowe et al, 1987) A perspective view of (III), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level and hydrogen bonds are displayed as dashed lines.…”

Section: Figurementioning

confidence: 99%

6-Chloroisocytosine and 5-bromo-6-methylisocytosine: again, one or two tautomers present in the same crystal?

Gerhardt

Bolte

2016

Acta Crystallogr C

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It is well known that pyrimidin-4-one derivatives are able to adopt either the 1H- or the 3H-tautomeric form in (co)crystals, depending on the coformer. As part of ongoing research to investigate the preferred hydrogen-bonding patterns of active pharmaceutical ingredients and their model systems, 2-amino-6-chloropyrimidin-4-one and 2-amino-5-bromo-6-methylpyrimidin-4-one have been cocrystallized with several coformers and with each other. Since Cl and Br atoms both have versatile possibilities to interact with the coformers, such as via hydrogen or halogen bonds, their behaviour within the crystal packing was also of interest. The experiments yielded five crystal structures, namely 2-aminopyridin-1-ium 2-amino-6-chloro-4-oxo-4H-pyrimidin-3-ide-2-amino-6-chloropyrimidin-4(3H)-one (1/3), C5H7N2(+)·C4H3ClN3O(-)·3C4H4ClN3O, (Ia), 2-aminopyridin-1-ium 2-amino-6-chloro-4-oxo-4H-pyrimidin-3-ide-2-amino-6-chloropyrimidin-4(3H)-one-2-aminopyridine (2/10/1), 2C5H7N2(+)·2C4H3ClN3O(-)·10C4H4ClN3O·C5H6N2, (Ib), the solvent-free cocrystal 2-amino-5-bromo-6-methylpyrimidin-4(3H)-one-2-amino-5-bromo-6-methylpyrimidin-4(1H)-one (1/1), C5H6BrN3O·C5H6BrN3O, (II), the solvate 2-amino-5-bromo-6-methylpyrimidin-4(3H)-one-2-amino-5-bromo-6-methylpyrimidin-4(1H)-one-N-methylpyrrolidin-2-one (1/1/1), C5H6BrN3O·C5H6BrN3O·C5H9NO, (III), and the partial cocrystal 2-amino-5-bromo-6-methylpyrimidin-4(3H)-one-2-amino-5-bromo-6-methylpyrimidin-4(1H)-one-2-amino-6-chloropyrimidin-4(3H)-one (0.635/1/0.365), C5H6BrN3O·C5H6BrN3O·C4H4ClN3O, (IV). All five structures show R2(2)(8) hydrogen-bond-based patterns, either by synthon 2 or by synthon 3, which are related to the Watson-Crick base pairs.

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Energetic multi-component molecular solids of tetrafluoroterephthalic acid with some aza compounds by strong hydrogen bonds and weak intermolecular interactions of C–H⋯F and C–H⋯O

Abstract: Tetrafluoroterephthalic acid forming nine new crystals with a series of N-containing heterocycles including salts/co-crystals/hydrates is discussed in context.

Cited by 40 publications

References 53 publications

Polarized Raman Reveals Alignment of Few-Layer MoS₂ Films

Polarized Raman Reveals Alignment of Few-Layer MoS₂ Films

Robustness of thioamide dimer synthon, carbon bonding and thioamide–thioamide stacking in ferrocene-based thiosemicarbazones

6-Chloroisocytosine and 5-bromo-6-methylisocytosine: again, one or two tautomers present in the same crystal?

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Energetic multi-component molecular solids of tetrafluoroterephthalic acid with some aza compounds by strong hydrogen bonds and weak intermolecular interactions of C–H⋯F and C–H⋯O

Abstract: Tetrafluoroterephthalic acid forming nine new crystals with a series of N-containing heterocycles including salts/co-crystals/hydrates is discussed in context.

Cited by 40 publications

References 53 publications

Polarized Raman Reveals Alignment of Few-Layer MoS2 Films

Polarized Raman Reveals Alignment of Few-Layer MoS2 Films

Robustness of thioamide dimer synthon, carbon bonding and thioamide–thioamide stacking in ferrocene-based thiosemicarbazones

6-Chloroisocytosine and 5-bromo-6-methylisocytosine: again, one or two tautomers present in the same crystal?

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Polarized Raman Reveals Alignment of Few-Layer MoS₂ Films

Polarized Raman Reveals Alignment of Few-Layer MoS₂ Films