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Search for "vibrational analysis" in Full Text gives 8 result(s) in Beilstein Journal of Organic Chemistry.

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

  • Shigeyuki Yamada,
  • Takuya Higashida,
  • Yizhou Wang,
  • Masato Morita,
  • Takuya Hosokai,
  • Kaveendra Maduwantha,
  • Kaveenga Rasika Koswattage and
  • Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

Graphical Abstract
  • geometries of 1a and 1c were optimized at the CAM-B3LYP/6-31+G(d) level of theory. The absence of any imaginary frequency in the vibrational analysis proved that the calculated structures are the minima. Figure 3 shows the calculated Mulliken charge distributions of fluorinated 1a and nonfluorinated 1c. The
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Published 29 May 2020

p-Pyridinyl oxime carbamates: synthesis, DNA binding, DNA photocleaving activity and theoretical photodegradation studies

  • Panagiotis S. Gritzapis,
  • Panayiotis C. Varras,
  • Nikolaos-Panagiotis Andreou,
  • Katerina R. Katsani,
  • Konstantinos Dafnopoulos,
  • George Psomas,
  • Zisis V. Peitsinis,
  • Alexandros E. Koumbis and
  • Konstantina C. Fylaktakidou

Beilstein J. Org. Chem. 2020, 16, 337–350, doi:10.3762/bjoc.16.33

Graphical Abstract
  • . From there, dissociation of the N–O bond starts to take place and proceeds uphill through a transition state, T1(TS), the structure of which was optimized fully. Vibrational analysis gives a single imaginary frequency (−550.12 cm−1) which corresponds to the N–O bond stretching confirming that the
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Published 09 Mar 2020

Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

  • Eric Detmar,
  • Valentin Müller,
  • Daniel Zell,
  • Lutz Ackermann and
  • Martin Breugst

Beilstein J. Org. Chem. 2018, 14, 1537–1545, doi:10.3762/bjoc.14.130

Graphical Abstract
  • approach was used to accelerate the calculations [56][57]. For the analysis of the substituent effect, the B3LYP functional with Grimme’s dispersion correction D3 (Becke–Johnson damping) was employed together with the def2-SVP basis set for all non-metals and the def2-TZVP basis set for Co. Vibrational
  • analysis verified that each structure was a minimum or transition state (iω < 30 cm−1 were tolerated). Thermal corrections were calculated from unscaled harmonic vibrational frequencies at the same levels of theory and refer to a standard state of 298.15 K and 1 mol L−1. Entropic contributions to the
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Published 25 Jun 2018

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

  • Martina Tireli,
  • Silvija Maračić,
  • Stipe Lukin,
  • Marina Juribašić Kulcsár,
  • Dijana Žilić,
  • Mario Cetina,
  • Ivan Halasz,
  • Silvana Raić-Malić and
  • Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

Graphical Abstract
  • alkyne and triazole products are marked with red and blue asterisks, respectively. For detailed vibrational analysis of these compounds please refer to Table S1, Supporting Information File 1. In situ Raman monitoring of a) mechanochemical formation of triazole 5 using copper(II) acetate monohydrate as
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Published 06 Nov 2017

Substitution effect and effect of axle’s flexibility at (pseudo-)rotaxanes

  • Friedrich Malberg,
  • Jan Gerit Brandenburg,
  • Werner Reckien,
  • Oldamur Hollóczki,
  • Stefan Grimme and
  • Barbara Kirchner

Beilstein J. Org. Chem. 2014, 10, 1299–1307, doi:10.3762/bjoc.10.131

Graphical Abstract
  • semiempirical methods. In our groups, we investigated the main binding motif for rotaxane systems of the Vögtle [27][28][29][30], Schalley- [29][30][31], and Leigh-type [27]. We performed an energetic and vibrational analysis for the twofold hydrogen bonds in order to understand the binding pattern [28]. A
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Published 05 Jun 2014

Use of activated enol ethers in the synthesis of pyrazoles: reactions with hydrazine and a study of pyrazole tautomerism

  • Denisa Tarabová,
  • Stanislava Šoralová,
  • Martin Breza,
  • Marek Fronc,
  • Wolfgang Holzer and
  • Viktor Milata

Beilstein J. Org. Chem. 2014, 10, 752–760, doi:10.3762/bjoc.10.70

Graphical Abstract
  • Formalism Polarizable Continuum Model) model including the effect of the solution was applied to optimize the geometries in (m)ethanol and DMSO. The stability of the obtained structures was proven by vibrational analysis (no imaginary vibrations). NMR chemical shifts δ (in ppm) were evaluated from the
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Published 01 Apr 2014

A new intermediate in the Prins reaction

  • Shinichi Yamabe,
  • Takeshi Fukuda and
  • Shoko Yamazaki

Beilstein J. Org. Chem. 2013, 9, 476–485, doi:10.3762/bjoc.9.51

Graphical Abstract
  • TS geometries were optimized. They were characterized by vibrational analysis, which checked whether the obtained geometries have single imaginary frequencies (ν‡s). From the TSs, reaction paths were traced by the intrinsic reaction coordinate (IRC) method [30][31] to obtain the energy-minimum
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Published 05 Mar 2013

SbCl3-catalyzed one-pot synthesis of 4,4′-diaminotriarylmethanes under solvent-free conditions: Synthesis, characterization, and DFT studies

  • Ghasem Rezanejade Bardajee

Beilstein J. Org. Chem. 2011, 7, 135–144, doi:10.3762/bjoc.7.19

Graphical Abstract
  • ′-diaminotriarylmethane derivatives in the presence of antimony trichloride as catalyst is described. Triarylmethane derivatives were prepared in good to excellent yields and characterized by elemental analysis, FTIR, 1H and 13C NMR spectroscopic techniques. The structural and vibrational analysis were investigated by
  • performing theoretical calculations at the HF and DFT levels of theory by standard 6-31G*, 6-31G*/B3LYP, and B3LYP/cc-pVDZ methods and good agreement was obtained between experimental and theoretical results. Keywords: diaminotriarylmethane; SbCl3; solvent-free reactions; synthesis; vibrational analysis
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Published 31 Jan 2011
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