Tautomerism of azo dyes in the solid state studied by 15N, 14N, 13C and 1H NMR spectroscopy, X-ray diffraction and quantum-chemical calculations

2020 ◽  
Vol 178 ◽  
pp. 108342 ◽  
Author(s):  
Kateřina Bártová ◽  
Ivana Císařová ◽  
Antonín Lyčka ◽  
Martin Dračínský
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Quantum Chemical Calculations ◽  
1H Nmr ◽  
Azo Dyes ◽  
Quantum Chemical ◽  
1H Nmr Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray

Influence of fluorine side-group substitution on the crystal structure formation of benzene-1,3,5-trisamides

CrystEngComm ◽  
2014 ◽  
Vol 16 (39) ◽  
pp. 9273-9283 ◽  
Author(s):  
Christoph Zehe ◽  
Marko Schmidt ◽  
Renée Siegel ◽  
Klaus Kreger ◽  
Venita Daebel ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
Structure Formation ◽  
Solid State Nmr ◽  
Quantum Chemical ◽  
Side Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Structure Formation

The crystal structure of 1,3,5-tris(2-fluoro-2-methylpropionylamino)benzene was solved by combining powder X-ray diffraction, solid-state NMR spectroscopy and quantum chemical calculations.

Encapsulation of L-Valine, D-Leucine and D-Methionine by Cucurbit[8]uril

CrystEngComm ◽  
2022 ◽  
Author(s):  
Zenghui Zhang ◽  
Rui-Lian Lin ◽  
Xiangyun Yu ◽  
Li-Xia Chen ◽  
Zhu Tao ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Solid State ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Binding Interactions ◽  
X Ray ◽  
X Ray Crystallography

The binding interactions of cucurbit[8]uril (Q[8]) with L-Valine, D-Leucine, and D-Methionine, both in aqueous solution and solid state, have been studied by 1H NMR spectroscopy and X-ray crystallography. 1H NMR...

A new aspect of the “pseudo water” concept of bis(trimethylsilyl)carbodiimide – “pseudohydrates” of aluminum

2018 ◽  
Vol 73 (11) ◽  
pp. 911-918
Author(s):  
Katrin Krupinski ◽  
Erica Brendler ◽  
Robert Gericke ◽  
Jörg Wagler ◽  
Edwin Kroke
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
Quantum Chemical ◽  
Metal Salt ◽  
Similar Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Positional Disorder ◽  
Cp Mas Nmr

AbstractBis(trimethylsilyl)carbodiimide (BTSC), so-called “pseudo water” because of some analogies such as similar (group)electronegativities of Me3Si– vs. H– and –N=C=N– vs. –O–, may form two different kinds of “pseudo hydrates” of metals (M), i.e. M–N(SiMe3)=C=N(SiMe3) and M–N≡C–N(SiMe3)2, derived from its carbodiimide and cyanamide isomeric forms, respectively. With anhydrous AlCl3 in Me3SiCl solution BTSC was shown to be capable of forming both kinds of solvates, i.e. Cl3Al–N(SiMe3)–C≡N(SiMe3) (1) and ((Cl3Al)(Me3Si)NCN)3–Al–(N≡C–N(SiMe3)2)3 (2). Both compounds were isolated as crystalline solids, which undergo condensation reactions upon storage. By single-crystal X-ray diffraction analysis the constitution of 1 was confirmed unambiguously, and quantum chemical calculations (B3LYP/6-311++g(d,p)) confirmed that compound 1 is 6 kcal mol−1 more stable than its hypothetical N,N-bis(trimethylsilyl)cyanamide isomer Cl3Al–N≡C–N(SiMe3)2. Compound 1 represents the first crystallographically confirmed disilylcarbodiimide complex of a metal salt. The molecules of compound 2 are heavily disordered in the solid state (positional disorder of N≡C–N(SiMe3)2 vs. N≡C–N(SiMe3)(AlCl3) and positional disorder of SiMe3 vs. AlCl3 groups in the latter). Therefore, the identity of 2 was additionally confirmed by 13C, 15N, 27Al and 29Si CP/MAS NMR spectroscopy.

Conformational study of blocked pentofuranoses and their 1,5-anhydro derivatives by 1H NMR spectroscopy

1984 ◽  
Vol 49 (1) ◽  
pp. 235-243
Author(s):  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Jiří Farkaš
Keyword(s):  
Spectral Analysis ◽  
Nmr Spectroscopy ◽  
Quantum Chemical Calculations ◽  
1H Nmr ◽  
Quantum Chemical ◽  
1H Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Conformational Study ◽  
H Nmr

Preferred conformations of the furanose ring and conformer population about the C(5)-C(4) bond in a series of benzoylated pentofuranosyl cyanides have been determined from their 1H NMR spectra. For the 1,5-anhydropentofuranose derivatives the results of the 1H NMR spectral analysis have been compared with the quantum chemical calculations.

scholarly journals 6,6′-Dimethyl-1,1′,5,5′-tetraaza-6,6′-bi(bicyclo[3.1.0]hexane): synthesis and investigation of molecular structure by quantum-chemical calculations, NMR spectroscopy and X-ray diffraction analysis

2021 ◽  
Author(s):  
Inna Nikolaevna Kolesnikova ◽  
Vladimir Vladimirovich Kuznetsov ◽  
Alexander Sergeevich Goloveshkin ◽  
Nikolai Andreevich Chegodaev ◽  
Nina Nikolaevna Makhova ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
X Ray Diffraction ◽  
X Ray

N-Heterocyclic Carbene-facilated Condensation of 3-Methylphenylboronic Acid to the Boroxine

2013 ◽  
Vol 68 (5-6) ◽  
pp. 453-457 ◽  
Author(s):  
Dongxiang Zhang ◽  
Jie Li ◽  
Xiao Dong ◽  
Xing Zhou ◽  
Zhi Yang ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
1H Nmr ◽  
Elemental Analysis ◽  
1H Nmr Spectroscopy ◽  
Phenylboronic Acid ◽  
X Ray Diffraction ◽  
X Ray

The adduct of (3-MeC6H4)3B3O3 with an N-heterocyclic carbene (NHC=1,3-diethyl-4,5- dimethylimidazol-2-ylidene) was prepared by reacting 2.5 equiv. of 3-methylphenylboronic acid with 1 equiv. of the NHC. This reaction shows a novel carbene-facilitated condensation of substituted phenylboronic acid monomers. The structure of the compound (3-MeC6H4)3B3O3(NHC) (1) has been characterized by 1H NMR spectroscopy, elemental analysis, and single-crystal X-ray diffraction studies

Hungry for charge – how a beryllium scorpionate complex “eats” a weakly coordinating anion

2020 ◽  
Vol 75 (5) ◽  
pp. 503-508
Author(s):  
Dominik Naglav-Hansen ◽  
Kevin Dzialkowski ◽  
Briac Tobey ◽  
Christoph Wölper ◽  
Georg Jansen ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Single Crystal ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr Spectroscopy ◽  
Weakly Coordinating ◽  
Weakly Coordinating Anion ◽  
Heteroleptic Complex

AbstractWe present the reaction of a tris(pyrazolyl) beryllium scorpionate (TpBe) complex with a weakly coordinating anion (WCA), which yields the heteroleptic complex TpBeOC(CF3)31 (TpBeORF). The product 1 has been characterized by multinuclear NMR spectroscopy (1H, 9Be, 13C) and single-crystal X-ray diffraction (scXRD). Quantum chemical calculations (DFT, NPA, LOL) were performed to study the bonding nature in 1.

Molecular and Crystal Structure of Chlorido[2-(N,N,N',N'- tetramethylamidinio)ethynido]silver

2013 ◽  
Vol 68 (5-6) ◽  
pp. 687-692
Author(s):  
Werner Weingärtner ◽  
Gerhard Maas
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Diffraction Analysis ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Silver Complex ◽  
State Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths

The solid-state structure of chlorido[2-(N,N,N',N'-tetramethylamidinio)ethynido]silver (3), obtained by C(sp)-metalation of N,N,N',N'-tetramethyl-propiolamidinium chloride with silver(I) oxide, has been determined by X-ray diffraction analysis. A comparison of bond lengths in the propiolamidinium moiety with those of the two genuine propiolamidinium salts 4 and 5, as well as with data for the isolated N,N,N',N'-tetramethyl-propiolamidinium cation obtained by quantum-chemical calculations, has been made. It can be concluded that complex 3 is better described as a (tetramethylamidinio) ethynyl than as a 3,3-bis(dimethylamino)allenylidene silver complex

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