نتایج جستجو برای: dft nmr

تعداد نتایج: 76720  

Journal: :Chemical science 2017
Feriel Rekhroukh Charlie Blons Laura Estévez Sonia Mallet-Ladeira Karinne Miqueu Abderrahmane Amgoune Didier Bourissou

The synthesis and characterization of the first gold(iii)-arene complexes are described. Well-defined (P,C)-cyclometalated gold(iii)-aryl complexes were prepared and characterized by NMR spectroscopy. These complexes swiftly and cleanly reacted with norbornene and ethylene to provide cationic gold(iii)-alkyl complexes, in which the remote phenyl ring was η2-coordinated to gold. The interaction ...

Journal: :Physical chemistry chemical physics : PCCP 2011
Iker del Rosal Torsten Gutmann Bernadeta Walaszek Iann C Gerber Bruno Chaudret Hans-Heinrich Limbach Gerd Buntkowsky Romuald Poteau

It is now well-known that (2)H solid-state NMR techniques can bring a better understanding of the interaction of deuterium with metal atoms in organometallic mononuclear complexes, clusters or nanoparticles. In that context, we have recently obtained experimental quadrupolar coupling constants and asymmetry parameters characteristic of deuterium atoms involved in various bonding situations in r...

Journal: :Molecules 2014
Pantelis Charisiadis Vassiliki G Kontogianni Constantinos G Tsiafoulis Andreas G Tzakos Michael Siskos Ioannis P Gerothanassis

Experimental parameters that influence the resolution of 1H-NMR phenol OH signals are critically evaluated with emphasis on the effects of pH, temperature and nature of the solvents. Extremely sharp peaks (Δν1/2≤2 Hz) can be obtained under optimized experimental conditions which allow the application of 1H-13C HMBC-NMR experiments to reveal long range coupling constants of hydroxyl protons and,...

Journal: :Dalton transactions 2013
Carmen R Barone Cecilia Coletti Ruth J McQuitty Nicola J Farrer Giuseppe Lorusso Luciana Maresca Alessandro Marrone Giovanni Natile Concetta Pacifico Simon Parsons Nazzareno Re Peter J Sadler Fraser J White

In this work UVA and blue light have been used to study photo-isomerisation about the C=C double bond in complexes of the type [PtCl(-CH=CHAr)(tmeda)] [Ar = C6H5, (E)-2a; 4-CH3O-C6H4, (E)-2b; 3-NO2-C6H4, (E)-2c; and 3-CH3O-C6H4, (E)-2d]. The progress of the reaction has been monitored by NMR spectroscopy following irradiation of the NMR sample. The NMR data have been complemented with X-ray dif...

2017
Jason D. Masuda

A new chloroform adduct of the N-heterocyclic carbene (NHC) 1,3-bis(2,6diisopropylphenyl)imidazolidin-2-ylidene (SIPr) has been prepared via C–H bond activation of the chloroform at the carbene carbon. This redox product was crystallized and was characterized by 1H and 13C-NMR spectroscopy, elemental analysis (EA), and single-crystal X-ray diffraction. The 1H and 13C-NMR spectroscopic data are ...

Journal: :Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 2015
Tao Wang Xueliang Wang

The title compounds, rabdosinate and rabdosin B, were isolated from the leaves of Isodon japonica, and characterized by IR-NMR spectroscopy. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO-13C) chemical shift values of the title compounds have been calculated by using DFT/B3LYP method with 6-311++G(d,p) basis set. In addition, obtained results were relat...

2017
Sander J Wezenberg Ben L Feringa

Toward the development of photoresponsive anion receptors, a stiff-stilbene photoswitch has been equipped with two urea anion-binding motifs. Photoinduced E/Z isomerization has been studied in detail by UV-vis and NMR spectroscopy. Titration experiments (1H NMR) reveal strong binding of acetate and phosphate to the (Z)-isomer, in which the urea groups are closely together. Isomerization to the ...

2013
Steven S Y Wong Michael G Brant Christopher Barr Allen G Oliver Jeremy E Wulff

Dipolar addition of cyclic azomethine imines with cyclic vinyl sulfones gave rise to functionalized tricycles that exhibited fluxional behavior in solution at room temperature. The scope of the synthetic methodology was explored, and the origin of the fluxional behavior was probed by NMR methods together with DFT calculations. This behavior was ultimately attributed to stereochemical inversion ...

2001
Walid Fathalla Michal Čajan

The regioselectivity of the model compound 4-methyl-1-thioxo1,2,4,5-tetrahydro[1,2,4]triazolo[4,3-a]quinazolin-5-one (3) towards different electrophiles was studied. Compound 3 reacts with alkyl and aryl halides to give the corresponding S-substituted derivatives. The reaction of the model thioamide with acyl halides proceeds by the formation of kinetically controlled S-acyl derivatives followe...

Journal: :Molecules 2008
Iwona Kowalczyk

1,1-Dimethyl-3-oxo-1,4-diazepan-1-ium chloride (1) and 1,1-dimethyl-1-carboxymethyl-3-aminopropyl ammonium hydrochloride (2) have been obtained by the reactions of 1,1-dimethyl-1,3-propylenediamine with ethyl chloroacetate and chloroacetic acid, respectively. The products have been characterized by FTIR, Raman and NMR spectroscopy. B3LYP calculations have also been carried out. The screening co...

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