Laser-Raman-Spektren der Ionen MoS42−, WS42−, MoOS32− und WOS32− in wässriger Lösung sowie der entsprechenden kristallinen Alkalisalze

Müller, Achim; Weinstock, N.; Schulze, Holger

doi:10.1016/0584-8539(72)80079-5

Cited by 37 publications

(12 citation statements)

References 14 publications

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“…Specifically, the spectrum comprises three lines at 452, 464, 478 cm –1 , which can be assigned to the v (Mo–S) vibration of the MoS 4 2– anion in K 2 MoS 4 . These results are found to be in agreement with the data collected by other authors. − These detailed XRD, Raman, structural, and compositional characterizations firmly confirm the successful preparation of solid precursor K 2 MoS 4 with good crystallinity and high purity.…”

Section: Results and Discussionsupporting

confidence: 90%

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS₂ from Crystalline K₂MoS₄ by in Situ Transmission Electron Microscopy

Zhang

Liu

et al. 2020

Crystal Growth & Design

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Understanding the chemical reaction kinetics and nucleation process in materials synthesis is significant for accurately regulating the size, morphology, and crystal structure of materials. In this article, we studied the chemical reaction and materials transformation from solid crystalline precursor K 2 MoS 4 to polycrystalline MoS 2 in a high-resolution transmission electron microscope at the atomic level. Through real time investigations, the nucleation dynamics and growth mechanism of layered MoS 2 from precursor K 2 MoS 4 were captured, identified, and revealed. It was found that MoS 2 nanocrystals can nucleate and grow not only along the well-expected low-index planes, but also along the high-index planes of the original precursor K 2 MoS 4 . These MoS 2 nanocrystals with different crystal orientations contact and coalesce to form a larger nanocrystal through the oriented attachment mode. Afterward, the growth and coalescence of these nanocrystals lead to the formation of a densely packed layered MoS 2 polycrystalline film. This study provides new insights into the nucleation and growth dynamics of materials and provides a promising way to investigate reaction dynamics on an atomic scale.

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Section: Results and Discussionsupporting

confidence: 90%

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS₂ from Crystalline K₂MoS₄ by in Situ Transmission Electron Microscopy

Zhang

Liu

et al. 2020

Crystal Growth & Design

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“…The corresponding bands for the tungsten analogue, 6 , were observed at 437 and 466 cm -1 . The MoS stretching bands for 11 are clearly shifted to lower energies relative to the corresponding IR bands for 8 (485 cm -1 ) and [Mo(S) 4 ] 2- (458 and 472 cm -1 ) …”

Section: Resultsmentioning

confidence: 94%

A New Entry into Molybdenum/Tungsten Sulfur Chemistry: Synthesis and Reactions of Mononuclear Sulfido Complexes of Pentamethylcyclopentadienyl−Molybdenum(VI) and −Tungsten(VI)

et al. 1997

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A series of mononuclear thio complexes of pentamethylcyclopentadienyl−molybdenum(VI) and −tungsten(VI) have been synthesized via C−S bond-cleaving reactions of thiolates. Use of Li2S2 for sulfurization of Cp*MoCl4 resulted in the known dinuclear complex, anti-Cp*2Mo2(S)2(μ-S)2 (1), while the analogous reaction of Cp*WCl4 gave rise to anti-Cp*2W2(S)2(μ-S)2 (2) and (PPh4)[Cp*W(S)3] (3), the latter of which was isolated after the subsequent cation exchange reaction with PPh4Br. In contrast, the reaction of Cp*WCl4 with Li2edt (edt = SCH2CH2S) followed by treatment with PPh4Br generated 3 as the sole isolable product in high yield. A similar reaction between Cp*WCl4 and LiStBu afforded Cp*W(S)2(StBu) (6), which turned out to be thermally unstable in solution and gradually degraded to 2. In these reactions of Cp*WCl4 with lithium thiolates, a facile C−S bond cleavage took place and the tungsten atom was oxidized from W(V) to W(VI). On the other hand, the Mo(IV) thiolate complexes, Cp*Mo(StBu)3 (4) and (PPh4)[Cp*Mo(edt)2] (5), were formed from the Cp*MoCl4/LiStBu and Cp*MoCl4/Li2edt/PPh4Br reaction systems. The complex 4 was readily oxidized by dry O2 producing Cp*Mo(O)2(StBu) (7) exclusively, while the reactions of 4 with NH2NMe2 and NH2NHPh occurred slowly to yield Cp*Mo(S)2(StBu) (8). The hydrazines acted as oxidants, presumably by cleaving the N−N bond, and promoted the C−S bond rupture of tert-butyl thiolate and concomitant oxidation of molybdenum from Mo(IV) to Mo(VI). Elemental sulfur S8 and grey selenium also acted as oxidants in the reactions with 4, leading to a complex mixture of products. From the 4 + S8 reaction, the complexes 1, 8, and Cp*Mo(O)(S)(StBu) (9) were produced, and the 4 + Se reaction lead to 8 and anti-Cp*2Mo2(E)2(μ-E)2 (10; E = S, Se). Finally treatment of 8 with Li2S2 and PPh4Br afforded (PPh4)[Cp*Mo(S)3] (11). We found that 11 was synthesized more easily by a one-pot reaction of 4, 1/4 equiv of S8, and Li2S2 in THF. The trithio complexes, 3 and 11, reacted very cleanly with PhC⋮CPh generating (PPh4)[Cp*M(S)(S2C2Ph2)] (M = W (12), Mo (13)), respectively. A kinetic study of these reactions showed that they were first order in PhC⋮CPh and first order in 3 or 11 with appreciable negative entropies of activation and that the activation barrier was higher for the molybdenum reaction. The crystal structures of 3−8 and 11−13 were determined by the X-ray analysis.

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“…18 In the crystalline structure of the salt, 9 the degeneracies are lifted and the internal modes appear as vibrational bands in the vicinity of these energies. Müller et al 19,20 have shown that the F 2 and the (EϩF 2 ) modes 17 The external modes of Cs 2 MoS 4 were observed in those experiments.…”

Section: B Raman Measurementsmentioning

confidence: 75%

High-pressure x-ray diffraction, absorption, luminescence, and Raman-scattering studyofCs2MoS4
Lorenz
¹
,
Orgzall
²
,
Dorhout
³

et al. 1997
Phys. Rev. B
7
0
4
0
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Cesium thiomolybdate, Cs 2 MoS 4 , has been investigated at pressures up to 12 GPa. Two phase transitions have been detected by absorption measurements, Raman spectroscopy, and energy dispersive x-ray diffraction. The first phase transition to a monoclinic phase II ͓aϭ14.061(9) Å, bϭ11.552(7) Å, cϭ9.852(6) Å, ␤ϭ97.14͑6͒°͔ has been observed at 8.0 GPa. The second transition at 9.7 GPa has been observed from the monoclinic phase II to an orthorhombic phase III ͓aϭ12.085(4) Å, bϭ15.707(6) Å, cϭ11.828(5) Å͔. Absorption and luminescence measurements have indicated an increase in the absorption edge energy with pressure up to ϳ3 GPa. At pressures greater than 3.5 GPa, the absorption energy decreases. Raman spectroscopy has revealed a low-frequency phonon mode with a negative pressure shift in the low-pressure phase I. The pressure-temperature phase diagram has been determined up to 250°C. The transition pressures decrease linearly with slopes of ϳϪ0.013 GPa/°C. Models for the pressure-induced structural and electronic transitions are proposed.

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Laser-Raman-Spektren der Ionen MoS42−, WS42−, MoOS32− und WOS32− in wässriger Lösung sowie der entsprechenden kristallinen Alkalisalze

Cited by 37 publications

References 14 publications

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS₂ from Crystalline K₂MoS₄ by in Situ Transmission Electron Microscopy

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS₂ from Crystalline K₂MoS₄ by in Situ Transmission Electron Microscopy

A New Entry into Molybdenum/Tungsten Sulfur Chemistry: Synthesis and Reactions of Mononuclear Sulfido Complexes of Pentamethylcyclopentadienyl−Molybdenum(VI) and −Tungsten(VI)

High-pressure x-ray diffraction, absorption, luminescence, and Raman-scattering studyofCs2MoS4
Lorenz
¹
,
Orgzall
²
,
Dorhout
³

et al. 1997
Phys. Rev. B
7
0
4
0
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Laser-Raman-Spektren der Ionen MoS42−, WS42−, MoOS32− und WOS32− in wässriger Lösung sowie der entsprechenden kristallinen Alkalisalze

Cited by 37 publications

References 14 publications

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS2 from Crystalline K2MoS4 by in Situ Transmission Electron Microscopy

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS2 from Crystalline K2MoS4 by in Situ Transmission Electron Microscopy

A New Entry into Molybdenum/Tungsten Sulfur Chemistry: Synthesis and Reactions of Mononuclear Sulfido Complexes of Pentamethylcyclopentadienyl−Molybdenum(VI) and −Tungsten(VI)

High-pressure x-ray diffraction, absorption, luminescence, and Raman-scattering studyofCs2MoS4Lorenz1, Orgzall2, Dorhout3 et al. 1997Phys. Rev. B7040View full textAdd to dashboardCite

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Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS₂ from Crystalline K₂MoS₄ by in Situ Transmission Electron Microscopy

Unveiling the Nucleation Dynamics and Growth Mechanism of Layered MoS₂ from Crystalline K₂MoS₄ by in Situ Transmission Electron Microscopy

High-pressure x-ray diffraction, absorption, luminescence, and Raman-scattering studyofCs2MoS4
Lorenz
¹
,
Orgzall
²
,
Dorhout
³

et al. 1997
Phys. Rev. B
7
0
4
0
View full text Add to dashboard Cite